polypeptides

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 604 protease inhibitors. MCE Protease Inhibitor Library is critical for drug discovery and development.

Cyclic peptides are polypeptide chains taking cyclic ring structure, which exhibit diverse biological activities, such as antibacterial activity, immunosuppressive activity and anti-tumor activity. Cyclic peptides, with the features of good binding affinity, target selectivity and low toxicity, show great success as therapeutics. Multiple cyclic peptides are currently in clinical use, for examples, gramicidin and tyrocidine with bactericidal activity, cyclosporin A with immunosuppressive activity, and vancomycin with antibacterial activity. Furthermore, cyclic peptides usually have the sufficient size and a balanced conformational flexibility/rigidity for binding to flat protein-protein interaction (PPI) interfaces, which have potential to develop PPI drugs.

MCE offers a unique collection of 84 cyclic peptides, all of which have good bioactivities. MCE Cyclic Peptide Library is a powerful tool for drug discovery and PPI inhibitor screening.

Polymixin B is a mixture of B1 and B2 polypeptides obtained from different strains of Bacillus polymyxa, with antibacterial activity against gram-negative bacteria. It can bind lipopolysaccharide (LPS) of the outer membrane of gram-negative bacteria and disrupts the cytoplasmic membrane by inducing large pores to allow nucleotide leakage in bacterial walls. This disrupts the permeability of the cytoplasmic membrane.