Is Inhibitors

Kinase is an enzyme that adds phosphate groups to other molecules. This process is known as phosphorylation. Protein phosphorylation is a key aspect in the regulation of a large number of cellular processes including cellular division, metabolism, signal transduction, and so on. There are over 500 kinases encoded by the human genome and it has been estimated that kinases regulate approximately 50% of cellular functions. Kinases are a large group of drug targets in drug discovery. Kinase inhibitors are an important class of drugs that block certain enzymes involved in diseases such as cancer and inflammatory disorders.

Kinase inhibitor library designed by MCE contains 2,673 kinase inhibitors and regulators mainly targeting protein kinases (VEGFR, EGFR, BTK, CDK, Akt, etc.), lipid kinases (PI3K, PI4K, SK, etc.) and carbohydrate kinases (Hexokinase), and is a useful tool for kinase drug discovery and related research.

According to reports, most known kinase inhibitors exert their effects through competitive binding in highly conserved ATP pockets. Although genetic techniques such as RNA interference can inactivate specific genes, most kinases are multi domain proteins, each of which has an independent function. Highly selective inhibitors have higher efficiency than non-selective inhibitors, and the selectivity to the target is at least 100 times higher. Therefore, ensuring the validation of targets with the most selective inhibitors is crucial for a more thorough understanding of the pharmacology of the kinase field. The Highly Selective Inhibitors Library contains 4,694 compounds, covering multiple targets and subtypes, such as GPCR protein family, Ion channel, multiple kinases, etc. The Highly Selective Inhibitors Library is an effective tool for screening different phenotypes

Protein phosphorylation is a key post-translational modification underlying the regulation of many cellular processes. Phosphatases and kinases contribute to the regulation of protein phosphorylation homeostasis in the cell. This reversible regulation of protein phosphorylation is critical for the proper control of a wide range of cellular activities, including cell cycle, proliferation and differentiation, metabolism, cell-cell interactions, etc.

Protein phosphatases have evolved in separate families that are structurally and mechanistically distinct. Based on substrate specificity and functional diversity, protein phosphatases are classified into two superfamilies: Protein serine/threonine phosphatases and Protein tyrosine phosphatases. Ser/Thr phosphatases are metalloenzymes belonging to two major gene families termed PPP (phosphoprotein phosphatase) and PPM (metal-dependent protein phosphatases), whereas protein tyrosine phosphatases (PTPs) belong to distinct classes of enzymes that utilize a phospho-cysteine enzyme intermediate as a part of their catalytic action.

MCE supplies a unique collection of 134 phosphatase inhibitors that mainly targeting protein tyrosine phosphatases (PTPs) and serine/threonine-specific protein phosphatases. MCE Phosphatase Inhibitor Library is a useful tool for phosphatase drug discovery and related research.

A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. Proteases play important roles in regulating multiple biological processes in all living organisms, such as regulating the fate, localization, and activity of many proteins, modulating protein-protein interactions, creating new bioactive molecules, contributing to the processing of cellular information, and generating, transducing, and amplifying molecular signals.

Proteases are important targets in drug discovery. Some protease inhibitors are often used as anti-virus drugs and anti-cancer drugs. MCE offers a unique collection of 605 protease inhibitors. MCE Protease Inhibitor Library is critical for drug discovery and development.

The PI3K/Akt/mTOR pathway controls many cellular processes that are important for the formation and progression of cancer, including apoptosis, transcription, translation, metabolism, angiogenesis, and cell cycle progression. Every major node of this signaling network is activated in a wide range of human tumors. Mechanisms for the pathway activation include activation of receptor tyrosine kinases (RTKs) upstream of PI3K, mutation or amplification of PIK3CA encoding p110α catalytic subunit of PI3K, mutation or loss of PTEN tumor suppressor gene, and mutation or amplification of Akt1. Once the pathway is activated, signaling through Akt can stimulate a series of substrates including mTOR which is involved in protein synthesis. Thus, inhibition of this pathway is an attractive concept for cancer prevention and/or therapy. Currently some mTOR inhibitors are approved for several indications, and there are several novel PI3K/Akt/mTOR inhibitors in clinical trials.

MCE owns a unique collection of 575 compounds that can be used for PI3K/Akt/mTOR pathway research. PI3K/Akt/mTOR Compound Library also acts as a useful tool for anti-cancer drug discovery.

MAPK families play an important role in complex cellular programs like proliferation, differentiation, development, transformation, and apoptosis. In mammalian cells, four MAPK families have been clearly characterized: ERK1/2, C-Jun N-terminal kinse/stress-activated protein kinase (JNK/SAPK) , p38 kinase and ERK5. They respond to different signals. Each MAPK-related cascade consists of three enzymes that are activated in series: a MAPK kinase kinase (MAPKKK), a MAPK kinase (MAPKK) and a MAP kinase (MAPK). MAPK signaling pathways has been implicated in the development of many human diseases including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and various types of cancers.

MCE designs a unique collection of 519 MAPK signaling pathway inhibitors that act as a useful tool for MAPK-related drug screening and disease research.

Cytokines are a kind of low molecular soluble proteins synthesized and secreted by immunogen, mitogen or other factors. They have functions of regulating innate and adaptive immune responses, promoting hematopoiesis, stimulating cell activation, proliferation and differentiation. The process of releasing a large number of cytokines is also called “Cytokine storm”, which can cause damage to many tissues and organs in the body. Cytokine is involved in the pathogenesis of many human diseases, including cancer, diabetes, chronic inflammatory diseases and so on. Cytokine inhibitors are a class of essential compounds that act by directly inhibiting the synthesis and release of cytokine or blocking the binding of cytokine to their receptors. Cytokine inhibitors are important compounds for the study of tumor and autoimmune diseases.

MCE designs a unique collection of 827 cytokine inhibitors, mainly targeting the receptor interleukin (IL), colony-stimulating factor (CSF), interferon (IFN), tumor necrosis factor (TNF), growth factor (GF) and chemokine, which is an effective tool for development and research of anti-cancer, anti-chronic inflammatory diseases and anti-autoimmune diseases compounds.

Chemokines, or chemotactic cytokines, are small cytokines or signaling proteins secreted by cells. They are a component of intercellular communication, controlling the directional movement of immune cells especially leukocytes, as well as other cell types, for instance, endothelial and epithelial cells, which are essential to maintain human health and the function of the immune system.

The biological effects of chemokines are achieved by binding to chemokine receptors, which are G protein-coupled receptors found on the surface of leukocytes. Some chemokine receptors are involved in directing tumor metastasis and over-expression by certain tumors. So inhibiting the interaction between chemokine and chemokine receptors on the surface of tumor cells may be a new possible therapeutic approach. Some chemokine receptors are coreceptors for HIV entry, and related inhibitors have been approved by the FDA to treat patients with HIV. Obviously, chemokines and chemokine receptors have become new targets for studying cancer, HIV, inflammation, and other diseases.

MCE supplies a unique collection of 149 chemokine or chemokine receptor inhibitors and activators, all of which have the identified inhibitory or activated effect on chemokine or chemokine receptors. MCE Chemokine Library is a useful tool for drug research related to cancer, AIDS, and wound therapy.

Potassium channels are the most widely distributed type of ion channel and are found in virtually all living organisms. There are four major classes of K channels: voltage-gated potassium channel, calcium-activated potassium channel, inwardly rectifying potassium channel and tandem pore domain potassium channel. There is growing evidence that dysfunction in potassium channels correlates with several diseases, such as chronic hypertension, diabetes, hypercholesterolemia and atherosclerosis, etc.

MCE Potassium Channel Compound Library consists of 215 potassium channel inhibitor and activators, which is a useful tool to discover drugs for cardiovascular diseases and potassium channel research.

GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory neurotransmitter in the vertebrate central nervous system. There are two classes of GABA receptors: GABAA and GABAB. GABAA receptors are ligand-gated ion channels (also known as ionotropic receptors), whereas GABAB receptors are G protein-coupled receptors (also known asmetabotropic receptors). GABA receptors are significant drug targets in the treatment of neuropsychiatric disorders such as epilepsy, insomnia, and anxiety, as well as in anesthesia in surgical operations.

MCE offers a unique collection of 139 GABA receptors inhibitors and activators, which is an efficient tool for neuropsychiatric disorders drugs discovery.

Protein serine/threonine kinases (PSKs) are protein kinases that use ATP as a high-energy donor molecule to transfer phosphate groups to serine/threonine residues of target protein. As an important signal transduction regulator, serine/threonine kinases can affect the function of target proteins by disrupting enzyme activity or binding of target proteins to other proteins. Serine/threonine kinases are involved in the regulation of immune response, cell proliferation, differentiation, apoptosis and other physiological processes. Serine/threonine kinase inhibitors are an important class of compounds that have been widely studied in cancer, chronic inflammation, autoimmune diseases, aging and other diseases.

MCE designs a unique collection of 1,286 serine/threonine kinase inhibitors, mainly targeting the receptor PKA, Akt, PKC, MAPK/ERK, etc, which is an effective tool for development and research of anti-cancer, anti-chronic inflammatory diseases, anti-autoimmune diseases and anti-aging compounds.

Nuclear receptors (NR) are proteins found in cells that sense androgen and thyroid hormones and certain other molecules. They are ligand-activated transcription factors that participate in many aspects of human physiology and pathology, and regulate the expression of various important genes.

Nuclear receptors have become one of the main targets in the development of new drug strategies, providing a unique type of receptors for studying a variety of human diseases, such as breast cancers, skin disorders and diabetes. 13% of U.S. Food and Drug Administration (FDA) approved drugs target nuclear receptors.

MCE supplies a unique collection of 668 nuclear receptor inhibitors and activators, all of which have the identified inhibitory or activated effect on nuclear receptor. MCE Nuclear Receptor Library is a useful tool for drugs research related to cancer, skin disease and diabetes.

Exosomes are small membrane vesicles of endocytic origin that are secreted by most cells in culture. Exosomes contain nucleic acids, proteins, lipids, amino acids, and metabolites, etc. Their diverse constituents can reflect their cell of origin. Exosomes are associated with immune responses, viral pathogenicity, pregnancy, cardiovascular diseases, central nervous system-related diseases, and cancer progression. Proteins, metabolites, and nucleic acids delivered by exosomes into recipient cells effectively alter their biological response. Such exosome-mediated responses can be disease promoting or restraining.

The biology of exosomes in disease is still emerging, and the number of studies addressing their utility in the diagnosis and treatment of various pathologies has increased substantially. MCE supplies a unique collection of 47 compounds with the activity of inhibiting or stimulating exsomes secretion/biosynthesis. MCE Exosomes Compound Library is a useful tool for exsomes research.

The majority of hypertensive patients have primary (or essential) hypertension, that is, hypertension in which secondary causes are not present. Management aims to control arterial pressure, prevent end-organ damage (cerebrovascular, cardiovascular, and renal), and reduce the risk of premature death.

Antihypertensive drugs may be divided into two broad groups, the first group being those which directly or indirectly block the renin–angiotensin system (RAS), for example, ACEIs, angiotensin receptor antagonists (ARAs), direct renin inhibitors (DRIs), and to a lesser extent β-blockers. The second group of drugs works by increasing water and sodium excretion, thereby reducing intravascular volume, or by causing vasodilatation through non-RAS pathways, for example, diuretics and calcium channel blockers (CCBs).

MCE offers a unique collection of 487 compounds with identified and potential antihypertensive activity. MCE Antihypertensive Compound Library is critical for antihypertensive drug discovery and development.

Copper is an important co-factor of all biological enzymes, but if the concentration exceeds the threshold of maintaining the homeostasis mechanism, copper will lead to cytotoxicity. This death mechanism has been named "Cuproptosis".

The mechanism of cuproptosis distinct from all other known mechanisms of regulated cell death, including apoptosis, pyroptosis, necroptosis, and ferroptosis.

Copper combine with the lipoylated components of the tricarboxylic acid cycle (TCA), leading to lipoylated protein aggregation and subsequent loss of iron-sulfur cluster proteins, ultimately resulting in protein toxicity stress and cell death. Studies have shown that the necessary factors for cuproptosis include the presence of glutathione, mitochondrial metabolism of galactose and pyruvate, and glutamine metabolism.

Targeted regulation of cuproptosis is a potential choice to treat cancer, rheumatoid arthritis, and other diseases. For example, up-regulation of LIPT1 may inhibit the occurrence and development of tumors by destroying TCA in mitochondria and then inducing cuproptosis.

MCE supplies a unique collection of 188 cuproptosis-related compounds, all of which act on the targets or signaling pathways related to cuproptosis and may have in inhibitory or activated effect on cuproptosis. MCE Cuproptosis Library is a useful tool for drug research related to cancer, rheumatoid arthritis, and other diseases.

5-HT receptors, also called Serotonin receptors, are a group of G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LGICs) found in the central and peripheral nervous systems. These receptors are now classified into seven families, 5-HT1–7, comprising a total of 14 structurally and pharmacologically distinct mammalian 5-HT receptor subtypes. The 5-HT receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, andthermoregulation. The serotonin receptors are the target of a variety of pharmaceutical drugs, including many antidepressants, antipsychotics, anorectics, antiemetics, gastroprokinetic agents, antimigraine agents, hallucinogens, and entactogens.

MCE 5-HT Receptor Compound Library consists of 310 5-HT receptor inhibitors and activators, which can be used for neuropsychiatric disorders drugs discovery.

Coagulation, also known as clotting, is the process in which blood changes from a liquid to a solid gel to form a blood clot. Thrombin, which is accurately and evenly generated in the injured part of blood vessels, is a key effector enzyme of the blood coagulation system and participates in many important biological processes, such as platelet activation, fibrinogen conversion to fibrin network, coagulation feedback amplification, etc. At the same time, to avoid the accidental formation of thrombus in the body, there is also an anticoagulant mechanism that inhibits blood coagulation.

Normal coagulation mechanism represents a balance between the pro-coagulant pathway in the injured site and anti-coagulant pathway beyond it. The blood coagulation system may be out of balance during the perioperative period or critical illness, which may lead to thrombosis or excessive bleeding. Therefore, the physiological study of coagulation balance is an important basis for clinical diagnosis and treatment of the abnormal coagulation process.

MCE supplies a unique collection of 973 compounds targeting key proteins in coagulation and anti-coagulation system. MCE Coagulation and Anti-coagulation Compound Library is a useful tool for study the mechanism of coagulation and anticoagulation.

Glycolysis is a series of metabolic processes by which one molecule of glucose is catabolized to two molecules of pyruvate with a net gain of two ATP. Glycolysis takes place in 10 steps and catalyzed by a series of enzyme, such as hexokinase, Glucose-6-phosphate isomerase, Phosphofructokinase, etc. Glycolysis is used by all cells in the body for energy generation.

Most cancer cells exhibit increased glycolysis and use this metabolic pathway for generation of ATP as a main source of their energy supply. This phenomenon is known as the Warburg effect and is considered as one of the most fundamental metabolic alterations during malignant transformation. Because increased aerobic glycolysis is commonly seen in a wide spectrum of human cancers, development of novel glycolytic inhibitors as a new class of anticancer agents is likely to have broad therapeutic applications.

MCE provides a unique collection of 696 glycolysis compounds that mainly target hexokinase, glucokinase, enolase, pyruvate kinase, PDHK, etc. MCE Glycolysis Compound Library is a useful tool for glucose metabolism research and anti-cancer drug discovery.

Protein tyrosine kinases (PTKs) are key signaling molecules and important drug targets. Two classes of PTKs are present in cells: the transmembrane receptor PTKs (RTKs) and the nonreceptor PTKs. The RTK family includes the receptors for insulin and for many growth factors, such as EGFR, FGFR, PDGFR, VEGFR, and NGFR. RTKs are transmembrane glycoproteins that are activated by the binding of their ligands, and they transduce the extracellular signal to the cytoplasm by phosphorylating tyrosine residues on the receptors themselves (autophosphorylation) and on downstream signaling proteins. Their principal functions of PTKs involve the regulation of multicellular aspects of the organism. Cell to cell signals concerning growth, differentiation, adhesion, motility, and death are frequently transmitted through tyrosine kinases. In humans, tyrosine kinases have been demonstrated to play significant roles in the development of many disease states, including diabetes and cancers.

MCE designs a unique collection of 1,064 compounds that act as a useful tool for PTKs-related drug screening and disease research.

The transforming growth factor beta (TGF-β) signaling pathway is involved in many cellular processes in both the adult organism and the developing embryo including cell growth, cell differentiation, apoptosis, cellular homeostasis and other cellular functions. The TGF-β superfamily comprises TGF-βs, bone morphogenetic proteins (BMPs), activins and related proteins. Signaling begins with the binding of a TGF beta superfamily ligand to a TGF beta type II receptor. The type II receptor is a serine/threonine receptor kinase, which catalyzes the phosphorylation of the Type I receptor. The type I receptor then phosphorylates receptor-regulated SMADs (R-SMADs) which can now bind the coSMAD (e.g. SMAD4). R-SMAD/coSMAD complexes accumulate in the nucleus where they act as transcription factors and participate in the regulation of target gene expression. Deregulation of TGF-β signaling contributes to developmental defects and human diseases, including cancers, some bone diseases, chronic kidney disease, etc.

MCE designs a unique collection of 226 TGF-beta/Smad signaling pathway compounds. TGF-beta/Smad Compound Library acts as a useful tool for TGF-beta/Smad-related drug screening and disease research.

Mutations in oncogenes and tumor suppressor genes can modify multiple signaling pathways and in turn cell metabolism, which facilitates tumorigenesis. The paramount hallmark of tumor metabolism is “aerobic glycolysis” or the Warburg effect, coined by Otto Warburg in 1926, in which cancer cells produce most of energy from glycolysis pathway regardless of whether in aerobic or anaerobic condition. Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside. The increased uptake of glucose is facilitated by the overexpression of several isoforms of membrane glucose transporters (GLUTs). Likewise, the metabolic pathways of glutamine, amino acid and fat metabolism are also altered. Recent trends in anti-cancer drug discovery suggests that targeting the altered metabolic pathways of cancer cells result in energy crisis inside the cancer cells and can selectively inhibit cancer cell proliferation by delaying or suppressing tumor growth.

MCE provides a unique collection of 2,068 compounds which cover various tumor metabolism-related signaling pathways. These compounds can be used for anti-cancer metabolism targets identification, validation as well anti-cancer drug discovery.

The developmental proteins Hedgehog, Notch and Wnt are key regulators of cell fate, proliferation, migration and differentiation in several tissues. Their related signaling pathways are frequently activated in tumors, and particularly in the rare subpopulation of cancer stem cells. The Wnt signaling pathway is a conserved pathway in animals. Deregulated Wnt signaling has catastrophic consequences for the developing embryo and it is now well appreciated that defective Wnt signaling is a causative factor for a number of pleiotropic human pathologies, including cancer. Hedgehog signaling pathway is linked to tumorigenesis and is aberrantly activated in a variety of cancers. The Notch signaling pathway is a highly conserved cell signaling system present in most animals. It plays an important role in cell-cell communication, and further regulates embryonic development.

MCE designs a unique collection of 358 Wnt/Hedgehog/Notch signaling pathway-related small molecules. Wnt/Hedgehog/Notch Compound Library serves as a useful tool for stem cell research and anti-cancer drug screening.

Adult stem cells are important for tissue homeostasis and regeneration due to their ability to self-renew and generate multiple types of differentiated daughters. Self-renewal is reflected by their capacity to undergo multiple/limitless divisions. Several signaling pathways are involved in self-renewal of stem cells, that is, Notch, Wnt, and Hedgehog pathways or Polycomb family proteins. Recent studies mainly focus on cancer stem cell (CSCs), induced pluripotent stem cell (iPSCs), neural stem cell and maintenance of embryonic stem cell pluripotency. Among them, CSCs have been believed to be responsible for tumor initiation, growth, and recurrence that have implications for cancer therapy.

MCE owns a unique collection of 1,757 compounds that can be used for stem cell regulatory and signaling pathway research.

Macrocycles, molecules containing 12-membered or larger rings, are receiving increased attention in small-molecule drug discovery. The reasons are several, including providing access to novel chemical space, challenging new protein targets, showing favorable ADME- and PK-properties. Macrocycles have demonstrated repeated success when addressing targets that have proved to be highly challenging for standard small-molecule drug discovery, especially in modulating macromolecular processes such as protein–protein interactions (PPI). Otherwise, the size and complexity of macrocyclic compounds make possible to ensure numerous and spatially distributed binding interactions, thereby increasing both binding affinity and selectivity.

MCE offers a unique collection of 367 macrocyclic compounds which can be used for drug discovery for high throughput screening (HTS) and high content screening (HCS). MCE Macrocyclic Compound Library is a useful tool for discovering new drugs, especially for “undruggable” targets and protein–protein interactions.

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases. However, the design of modulators targeting PPI still faces tremendous challenges, such the difficult PPI interfaces for the drug design, lack of ligands reference, lack of guidance rules for the PPI modulators development and high-resolution PPI proteins structures.

The PPI Library comprises molecules of various sizes, frameworks, and shapes ranging from fragment-like entities to macrocyclic derivatives designed as secondary structure mimetics or as epitope mimetics. The designs cover β-turn / loop mimetics and α-helix mimetics. Since helices present at the interface in 62% of all protein-protein interactions. This library focused on designs including mimics with the substitution geometry of an a-helices, as well as designs that mimic the location of “hot-spot” side chains in helix-mediated PPIs.

Small molecule covalent inhibitors, or irreversible inhibitors, are a type of inhibitors that exert their biological functions by irreversibly binding to target through covalent bonds. Compared with non-covalent inhibitors, covalent inhibitors have obvious advantages in bioactivity, such that covalent warheads can target rare residues of a particular target protein, thus leading to the development of highly selective inhibitors and achieving a more complete and continued target occupancy in living systems. In recent years, the distinct strengths of covalent inhibitors in overcoming drug resistance had been recognized. However, toxicity can be a real challenge related to this class of therapeutics due to their potential for off-target reactivity and has led to these drugs being disfavored as a drug class. The drug design and optimization of covalent inhibitors has become a hot spot in drug discovery.

MCE covalent inhibitor library contains 2,996 small molecules including identified covalent inhibitors and other molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

MCE Covalent inhibitor Library plus, with more powerful screening capability, further complement Covalent inhibitor Library (HY-L036) by adding some fragment compounds with covalent warheads.

Small molecule covalent inhibitors, or irreversible inhibitors, are a type of inhibitors that exert their biological functions by irreversibly binding to target through covalent bonds. Compared with non-covalent inhibitors, covalent inhibitors have obvious advantages in bioactivity, such that covalent warheads can target rare residues of a particular target protein, thus leading to the development of highly selective inhibitors and achieving a more complete and continued target occupancy in living systems. In recent years, the distinct strengths of covalent inhibitors in overcoming drug resistance had been recognized. However, toxicity can be a real challenge related to this class of therapeutics due to their potential for off-target reactivity and has led to these drugs being disfavored as a drug class. The drug design and optimization of covalent inhibitors has become a hot spot in drug discovery.

MCE covalent inhibitor library contains 1,676 small molecules including identified covalent inhibitors and other bioactive molecules having common covalent reactive groups as warheads, such as acrylamides, activated terminal acetylenes, Sulfonyl fluorides/esters, cloracetamides, alkyl halides, epoxides, aziridines, disulfides, etc.

Stem cells, which are found in all multi-cellular organisms, can divide and differentiate into diverse special cell types and can self-renew to produce more stem cells. To be useful in therapy, stem cells must be converted into desired cell types as necessary which is called induced differentiation or directed differentiation. Understanding and using signaling pathways for differentiation is an important method in successful regenerative medicine. Small molecules or growth factors induce the conversion of stem cells into appropriate progenitor cells, which will later give rise to the desired cell type. There is a variety of signal molecules and molecular families that may affect the establishment of germ layers in vivo, such as fibroblast growth factors (FGFs); the wnt family or superfamily of transforming growth factors β (TGFβ) and bone morphogenetic proteins (BMP). Unfortunately, for now, a high cost of recombinant factors is likely to limit their use on a larger scale in medicine. The more promising technique focuses on the use of small molecules. These small molecules can be used for either activating or deactivating specific signaling pathways. They enhance reprogramming efficiency by creating cells that are compatible with the desired type of tissue. It is a cheaper and non-immunogenic method.

MCE Differentiation Inducing Compound Library contains a unique collection of 1,447 compounds that act on signaling pathways for differentiation. These compounds are potential stimulators for induced differentiation. This library is a useful tool for researching directed differentiation and regenerative medicine.

Neurotransmitter (NT) receptors, also known as neuroreceptors, are a broadly diverse group of membrane proteins that bind neurotransmitters for neuronal signaling. There are two major types of neurotransmitter receptors: ionotropic and metabotropic. Ionotropic receptors are ligand-gated ion channels, meaning that the receptor protein includes both a neurotransmitter binding site and an ion channel. The binding of a neurotransmitter molecule (the ligand) to the binding site induces a conformational change in the receptor structure, which opens, or gates, the ion channel. The term “metabotropic receptors” is typically used to refer to transmembrane G-protein-coupled receptors. Metabotropic receptors trigger second messenger-mediated effects within cells after neurotransmitter binding.

In some neurological diseases, the neurotransmitter receptor itself appears to be the target of the disease process. Many neuroactive drugs act by modifying neurotransmitter receptors. A better understanding of neurotransmitter receptor changes in disease may lead to improvements in therapy.

MCE designs a unique collection of 1,806 compounds targeting a variety of neurotransmitter receptors. MCE Neurotransmitter Receptor Compound Library is a useful tool for neurological diseases drug discovery.

Antibody inhibitors are compounds with the same activity as the original therapeutic antibodies, which can be used as positive controls for drug efficacy evaluation and other studies. Antibody inhibitors can also assist in verifying the functional activity of the target protein. These antibody inhibitors are active in vivo and can achieve certain physiological functions by blocking or neutralizing target proteins, such as CD20, HER2, EGFR, VEGFR, TNF-α, etc. In drug screening, antibody inhibitor-based screening can be carried out to identify active compounds targeting target proteins and target diseases.

MCE can provide 21 antibody inhibitors that can be used for drug development in cancer, immunity, infection and other hot research areas.

A unique set of molecules containing mild electrophilic moieties that covalently interact with amino acid residues in the target protein. The diversity of our compounds for covalent drug discovery ranges from natural product-like scaffolds to macrocycles, creating multiple opportunities in hit generation for a selected target.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is central to signaling by cytokine receptors, a superfamily of more than 30 transmembrane proteins that recognize specific cytokines, and is critical in blood formation and immune response. Canonical JAK/STAT signaling begins with the association of cytokines and their corresponding transmembrane receptors. Activated JAKs then phosphorylate latent STAT monomers, leading to dimerization, nuclear translocation, and DNA binding. In mammals, there are four JAKs (JAK1, JAK2, JAK3, TYK2) and seven STATs (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, STAT6). Since the JAK/STAT pathway plays a major role in many fundamental processes, such as apoptosis and inflammation, dysfunctional proteins in the pathway may lead to a number of diseases. For example, alterations in JAK/STAT signalling can result in cancer and diseases affecting the immune system, such as severe combined immunodeficiency disorder (SCID).

MCE provides 424 compounds that can be used in the study of the JAK/STAT signaling pathway and related diseases.

Endoplasmic reticulum (ER) contributes to the production and folding of approximately one third of cellular proteins, and is thus inextricably linked to the maintenance of cellular homeostasis and the fine balance between health and disease. However, some adverse factors negatively impact ER functions and protein synthesis, resulting in the activation of Endoplasmic reticulum stress (ER stress, ERS) and unfolded protein response (UPR) signaling pathways. The UPR is triggered when ER protein folding capacity is overwhelmed by cellular demand and the UPR initially aims to restore ER homeostasis and normal cellular functions. However, if this fails, then the UPR triggers cell death. Chronic ER stress and defects in UPR signaling are emerging as key contributors to a growing list of human diseases, including diabetes, neurodegeneration and cancer.

MCE Endoplasmic Reticulum Stress Compound Library contains 221 ER stress-related compounds that mainly target PERK, IRE1, ATF6, etc. MCE ER stress library is a useful tool for researching ER stress and related diseases.

Mitochondria plays an important role in many vital processes in cells, including energy production, fatty-acid oxidation and the Tricarboxylic Acid (TCA) cycle, calcium signaling, permeability transition, apoptosis and heat production. At present, it is recognized that many diseases are associated with impaired mitochondrial function, such as increased accumulation of ROS and decreased OXPHOS and ATP production. Mitochondria are recognized as one of the most important targets for new drug design in cancer, cardiovascular, and neurological diseases, etc. Some small molecule drugs or biologics can act on mitochondria through various pathways, including ETC inhibition, OXPHOS uncoupling, mitochondrial Ca²⁺ modulation, and control of oxidative stress via decrease or increase of mitochondrial ROS accumulation.

MCE supplies a unique collection of 894 mitochondria-targeted compound that mainly targeting Mitochondrial Metabolism, ATP Synthase, Mitophagy, Reactive Oxygen Species, etc. MCE Mitochondria-Targeted Compound Library is a useful tool for mitochondria-targeted drug discovery and related research.

Bioactive compounds are a general term for a class of substances that can cause certain biological effects in the body, which are the main source of small molecule drugs. These compounds generally penetrate cell membranes, act on specific target proteins in cells, regulate intracellular signaling pathways, and cause some changes in cell phenotype.

MCE owns a unique collection of 18,934 compounds with confirmed biological activities and clear targets. These compounds include natural products, innovative compounds, approved compounds, and clinical compounds. These can also be used for signal pathway research, drug discovery and drug repurposing, etc.

The blood-brain barrier (BBB) is the complex network of brain microvessels. It protects the brain from the external bloodstream environment and supplies the brain with the required nutrients for normal function. However, blood-brain barrier is also the obstacle to deliver beneficial drugs to treat CNS (central nervous system) diseases or brain tumors, as it has the least permeable capillaries in the entire body due to physical barriers (tight junctions). Therefore, it is crucial to discover drugs which can cross this barrier for the treatment of brain-based diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and epilepsy.

MCE offers a unique collection of 858 compounds with confirmed CNS-Penetrant property. It’s a useful tool for the discovery of drugs used for brain diseases, such as brain tumors, mental disorders, and neurodegenerative diseases.

Glutamine is an important metabolic fuel that helps rapidly proliferating cells meet the increased demand for ATP, biosynthetic precursors, and reducing agents. Glutamine Metabolism pathway involves the initial deamination of glutamine by glutaminase(GLS), yielding glutamate and ammonia. Glutamate is converted to the TCA cycle intermediate α-ketoglutarate (α-KG) by either glutamate dehydrogenase (GDH) or by the alanine or aspartate transaminases (TAs), to produce both ATP and anabolic carbons for the synthesis of amino acids, nucleotides and lipids. During periods of hypoxia or mitochondrial dysfunction, α-KG can be converted to citrate in a reductive carboxylation reaction catalyzed by IDH2. The newly formed citrate exits the mitochondria where it is used to synthesize fatty acids and amino acids and produce the reducing agent, NADPH.

Cancer cells display an altered metabolic circuitry that is directly regulated by oncogenic mutations and loss of tumor suppressors. Mounting evidence indicates that altered glutamine metabolism in cancer cells has critical roles in supporting macromolecule biosynthesis, regulating signaling pathways, and maintaining redox homeostasis, all of which contribute to cancer cell proliferation and survival. Thus, intervention in glutamine metabolic processes could provide novel approaches to improve cancer treatment.

MCE owns a unique collection of 917 compounds targeting the mainly proteins and enzymes involved in glutamine metabolism pathway. Glutamine Metabolism compound library is a useful tool for intervention in glutamine metabolic processes.

A histone modification, a covalent post-translational modification (PTM) to histone proteins, includes methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation, etc. In general, histone modifications are catalyzed by specific enzymes that act predominantly at the histone N-terminal tails involving amino acids such as lysine or arginine, as well as serine, threonine, tyrosine, etc. The PTMs made to histones can impact gene expression by altering chromatin structure or recruiting histone modifiers. Histone modifications act in diverse biological processes such as transcriptional activation/inactivation, chromosome packaging, and DNA damage/repair. Deregulation of histone modification contributes to many diseases, including cancer and autoimmune diseases.

MCE owns a unique collection of 629 bioactive compounds targeting Epigenetic Reader Domain, HDAC, Histone Acetyltransferase, Histone Demethylase, Histone Methyltransferase, Sirtuin, etc. Histone Modification Research Compound Library is a useful tool for histone modification research and drug screening.

Metabolism is the set of life-sustaining chemical reactions in organisms. Metabolic pathways are enzyme-mediated biochemical reactions that lead to biosynthesis (anabolism) or breakdown (catabolism) of natural product small molecules within a cell or tissue. Acting as catalysts, enzymes are crucial to metabolism - they allow a reaction to proceed more rapidly - and they also allow the regulation of the rate of a metabolic reaction. Proteases are used throughout an organism for various metabolic processes. Proteases control a great variety of physiological processes that are critical for life, including the immune response, cell cycle, cell death, wound healing, food digestion, and protein and organelle recycling. Imbalances in metabolic activities have been found to be critical in a number of pathologies, such as cardiovascular diseases, inflammation, cancer, and neurodegenerative diseases.

MCE designs a unique collection of 4,475 Metabolism/Protease-related small molecules that act as a useful tool for drug discovery of metabolism-related diseases.

Most of molecules enter or leave cells mainly via membrane transport proteins, which play important roles in several cellular functions, including cell metabolism, ion homeostasis, signal transduction, the recognition process in the immune system, energy transduction, etc. There are three major types of transport proteins, ATP-powered pumps, channel proteins and transporters. Transport proteins such as channels and transporters play important roles in the maintenance of intracellular homeostasis, and mutations in these transport protein genes have been identified in the pathogenesis of a number of hereditary diseases. In the central nervous system, ion channels have been linked to, but not limited to, many diseases such asataxias, paralyses, epilepsies, and deafness. This indicates the roles of ion channels in the initiation and coordination of movement, sensory perception, and encoding and processing of information. Ion channels are a major class of drug targets in drug development.

MCE designs a unique collection of 1,404 smal-molecule modulators that can be used for the research of Ion Channel and Membrane Transporter or high throughput screening (HTS) related drug discovery.

Protein ubiquitination is an enzymatic post-translational modification in which an ubiquitin protein is attached to a substrate protein. Ubiquitination involves three main steps: activation, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. Ubiquitination affects cellular processes such as apoptosis, cell cycle, DNA damage repair, and membrane transportation, etc. by regulating the degradation of proteins (via the proteasome and lysosome), altering the cellular localization of proteins, affecting proteins activity, and promoting or preventing protein-protein interactions. Deregulation of ubiquitin pathway leads to many diseases such as neurodegeneration, cancer, infection and immunity, etc.

MCE offers a unique collection of 257 small molecule modulators with biological activity used for ubiquitination research. Compounds in this library target the key enzymes in ubiquitin pathway. MCE Ubiquitination Compound Library is a useful tool for the research of ubiquitination regulation and the corresponding diseases.

Nuclear factor-κB (NF-κB)/Rel proteins include NF-κB2 p52/p100, NF-κB1 p50/p105, c-Rel, RelA/p65, and RelB. These proteins function as dimeric transcription factors that regulate the expression of genes and influence a broad range of biological processes including innate and adaptive immunity, inflammation, stress responses, B-cell development, and lymphoid organogenesis. NF-κB plays a key role in regulating the immune response to infection. In addition, activation of the NF-κB pathway is involved in the pathogenesis of chronic inflammatory diseases, such as asthma, rheumatoid arthritis, and inflammatory bowel disease. Incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development.

MCE owns a unique collection of 809 small molecule compounds that can be used in the research of NF-κB signaling pathway or high throughput screening (HTS) related drug discovery.

Neuronal Signaling is involved in the regulation of the mechanisms of the central nervous system (CNS) such as its structure, function, genetics and physiology as well as how this can be applied to understand diseases of the nervous system. Every information processing system in the CNS is composed of neurons and glia, neurons have evolved unique capabilities for intracellular signaling (communication within the cell) and intercellular signaling (communication between cells). G protein-coupled receptors (GPCRs), including 5-HT receptor, histamine receptor, opioid receptor, etc. are the largest class of sensory proteins and are important therapeutic targets in Neuronal Signaling. Besides, Notch signaling, such as β- and γ-secretase, also plays multiple roles in the development of the CNS including regulating neural stem cell (NSC) proliferation, survival, self-renewal and differentiation. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Notch signaling in neurons, glia, and NSCs is also involved in pathological changes that occur in disorders such as stroke, Alzheimer's disease and CNS tumors. Thus, targeting Neuronal Signaling, such as notch signaling and GPCRs, can be used as therapeutic interventions for several different CNS disorders.

MCE designs a unique collection of 2,572 Neuronal Signaling-related compounds that act as a useful tool for the research of neuronal regulation and neuronal diseases.

Covalent inhibitors are small molecules that can bind specifically to target proteins through covalent bonds and inhibit their biological functions. Although for a long time, covalent targeting has been playing a subordinate role in drug discovery, with an increasing number of reports on successful clinical applications of such drugs, the potential of these agents is now being acknowledged. Currently, cysteine is the most common covalent amino acid residue in a variety of covalent drugs, and various warheads have been developed that can react with cysteine, providing the key building blocks for covalent drugs to form covalent bonds.

To meet the development needs of covalent inhibitors targeting cysteine, MCE has designed a unique collection of 4,528 compounds with different covalent warheads that target cysteine. The MCE Cysteine Targeted Covalent Library is designed using the following covalent warheads: Acrylamides, Propiolic acid ester, Dimethylamine functionalized acrylamides, Chloroacetamides, Acrylonitrile, 2-Cyanoacrylamide, Aziridine, Haloacetamide, etc.

Protein protein interactions (PPI) have pivotal roles in life processes. The studies showed that aberrant PPI are associated with various diseases, including cancer, infectious diseases, and neurodegenerative diseases. The classic drug targets are usually enzymes, ion channels, or receptors, the PPI indicate new potential therapeutic targets. Therefore, targeting PPI is a new direction in treating diseases and an essential strategy for the development of new drugs.

However, the design of modulators targeting PPI still faces tremendous challenges, such the difficult PPI interfaces for the drug design, lack of ligands reference, lack of guidance rules for the PPI modulators development and high-resolution PPI proteins structures.

With the development of high-throughput technology, high-throughput screening is also gradually used for the identification of PPI inhibitors, but the compound library used for conventional target screening is not very effective in screening PPI inhibitors. To improve screening efficiency, MCE carefully selected 583 PPI inhibitors and mainly targeting MDM2-p53, Keap1-Nrf2, PD-1/PD-L1, Myc-Max, etc. MCE Protein-protein Interaction Inhibitor Library is a useful tool for PPI drug discovery and related research.

Angiogenesis is the physiological process through which new blood vessels are formed from pre-existing vessels. It occurs in various physiological processes e.g. embryonic development, menstrual cycle, exercise and wound healing etc. Angiogenesis is regulated by both endogenous activators and inhibitors. Some key activators of angiogenesis include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), angiogenin, TGF-β, etc. whereas angiogenesis inhibitors are angiostatin, endostatin, interferon, platelet factor 4, etc. The loss of balance between these opposing signals leads to life threatening diseases like cancer, cardiovascular and ischemic diseases etc. which are thus controlled by exogenous angiogenesis activators (for cardiovascular/ischemic disorders) and inhibitors (for cancer).

MCE offers a unique collection of 2,003 compounds with validated angiogenesis targets modulating properties. MCE angiogenesis-related compound library is an effective tool for angiogenesis research and discovery of angiogenesis-related drugs.

Covalent inhibitors are small molecules that can bind specifically to target proteins through covalent bonds and inhibit their biological functions. Although for a long time, covalent targeting has been playing a subordinate role in drug discovery, with an increasing number of reports on successful clinical applications of such drugs, the potential of these agents is now being acknowledged. Currently, cysteine is the most common covalent amino acid residue in a variety of covalent drugs, and various warheads have been developed that can react with cysteine, providing the key building blocks for covalent drugs to form covalent bonds.

To meet the development needs of covalent inhibitors targeting cysteine, MCE has designed a unique collection of 3,165 fragments with different covalent warheads that target cysteine. The MCE Cysteine Targeted Covalent Fragment Library is designed using the following covalent warheads: Acrylamides, Propiolic acid ester, Dimethylamine functionalized acrylamides, Chloroacetamides, Acrylonitrile, 2-Cyanoacrylamide, Aziridine, Haloacetamide, etc. All fragments are pre-filtered with the Rule of Three restrictions which can be used for fragment-based covalent drug development.

Nucleoside and nucleotide analogues are synthetic, chemically modified compounds that have been developed to mimic their physiological counterparts in order to exploit cellular metabolism and subsequently be incorporated into DNA and RNA to inhibit cellular division and viral replication. In addition to their incorporation into nucleic acids, nucleoside and nucleotide analogues can interact with and inhibit essential enzymes such as human and viral polymerases (that is, DNA-dependent DNA polymerases, RNA-dependent DNA polymerases or RNA-dependent RNA polymerases), kinases, ribonucleotide reductase, DNA methyltransferases, purine and pyrimidine nucleoside phosphorylase and thymidylate synthase. These actions of nucleoside and nucleotide analogues have potential therapeutic benefits — for example, in the inhibition of cancer cell growth, the inhibition of viral replication as well as other indications.

MCE offers a unique collection of 497 nucleotide compounds including nucleotide, nucleoside and their structural analogues. MCE Nucleotide Compound Library is a useful tool to discover anti-cancer and antiviral drugs for high throughput screening (HTS) and high content screening (HCS).

Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. PROTACs consist of a ligand for E3 ligase (E3 ligase binder), a linker and a ligand (mostly small-molecule inhibitor) for protein of interest（target binder）. Upon binding to the target protein, the PROTACs can recruit E3 for target protein ubiquitination, which is subjected to proteasome-mediated degradation. Therefore, PROTACs execute their functions by degrading the target proteins rather than inhibiting them, which has a great superiority in overcoming resistance caused by target mutation or overexpression. To date, PROTAC technology has been applied to a variety of targets, including AR, ER, BTK, BET, and BCR-ABL to overcome resistance.

MCE carefully prepared a unique collection of 39 ligands for target proteins, which have been reported to be used in PROTAC design. MCE Target Protein Ligand Library is a useful tool for PROTAC development.