protein-containing complex calprotectin complex cellular_component 2015-02-25T14:03:17Z An example of this is S100A9 in human (UniProt symbol P06702) in PMID:25417112 (inferred from direct assay). GO:1990660 bhm A protein complex composed of S100A8 and S100A9 and capable of limiting Mn(2+) and Zn(2+) availability at sites of infection. Also binds Ca(2+). Expressed and released by neutrophils and epithelial cells, it exhibits broad-spectrum antimicrobial activity attributed to its metal-binding properties. Endogenous ligand of toll-like receptor 4 (TLR4) and of the receptor for advanced glycation end products (RAGE) initiating signal transduction through NF-kappa-B pathways. calprotectin heterodimer