S100A8-S100A9 Heterodimer Protein, Human (sf9, Flag-His)

The S100A8, composed of calcium- and zinc-binding S100A8, crucially regulates inflammation and immune responses. As calprotectin, it aids leukocyte functions, modulates cytoskeleton, and activates NADPH-oxidase intracellularly. Extracellularly, it displays pro-inflammatory, antimicrobial, and apoptosis-inducing activities, acting as a DAMP molecule that stimulates innate immune cells through TLR4 and AGER. With antimicrobial effects, it regulates neutrophils, induces cell death, and prevents tissue damage. Notably, it amplifies inflammation in autoimmunity and cancer, potentially influencing aberrant neutrophil expansion in microbial infections like SARS-CoV-2. S100A8-S100A9 Heterodimer Protein, Human (sf9, Flag-His) is a recombinant protein dimer complex containing human-derived S100A8-S100A9 Heterodimer protein, expressed by Sf9 insect cells, with C-His, C-Flag labeled tag. S100A8-S100A9 Heterodimer Protein, Human (sf9, Flag-His), has molecular weight of ~12.2 & 14.2 kDa, respectively.

S100A8, plays a crucial role in regulating inflammatory processes and immune responses. Often found as calprotectin (S100A8/A9), it serves diverse intracellular functions, including facilitating leukocyte arachidonic acid trafficking and metabolism, modulating the tubulin-dependent cytoskeleton during phagocyte migration, and activating the neutrophilic NADPH-oxidase. In particular, it activates NADPH-oxidase by aiding in the assembly of the enzyme complex at the cell membrane, transferring arachidonic acid, and directly binding to NCF2/P67PHOX. Extracellularly, it exhibits pro-inflammatory, antimicrobial, oxidant-scavenging, and apoptosis-inducing activities. Acting as an alarmin or danger-associated molecular pattern (DAMP) molecule, S100A8 stimulates innate immune cells through binding to pattern recognition receptors such as Toll-like receptor 4 (TLR4) and receptor for advanced glycation endproducts (AGER), activating MAP-kinase and NF-kappa-B signaling pathways and amplifying the pro-inflammatory cascade. With antimicrobial activity against bacteria and fungi, it likely exerts this effect through Zn(2+) chelation essential for microbial growth. Additionally, S100A8/A9 induces cell death via autophagy and apoptosis, regulates neutrophil number and apoptosis, and acts as an oxidant scavenger to prevent tissue damage. It acts as an amplifier of inflammation in autoimmunity and cancer development, and in microbial infection, such as by SARS-CoV-2, it may induce expansion of aberrant immature neutrophils in a TLR4-dependent manner.

Human

Sf9 insect cells

C-His;C-Flag

P05109 (M1-E93)&P06702 (M1-P114)

6279  [NCBI]&6280  [NCBI]

Approximately 12.2&14.2 kDa

Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized from a 0.2 μm filtered solution of 50 mM Tris, 500 mM NaCl, 10% Glycerol, pH 8.0. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.