S-100 Antibody

S-100 protein is a 21-kDa component isolated first from the brain but later found in a wide variety of normal and neoplastic cells of mesodermal, neuroectodermal, and epithelial origins. The S-100 protein is found in 3 forms: S-100a(0), a homodimer of alpha-alpha subunits; S-100a, a heterodimer of alpha-beta subunits; and, S-100b, a homodimer of beta-beta subunits. S-100 binds to and initiates the activation of STK38 by releasing autoinhibitory intramolecular interactions within the kinase. Interaction with AGER after myocardial infarction plays a role in myocyte apoptosis by activating ERK1/2 and p53/TP53 signaling. S-100 weakly binds calcium but binds zinc with a higher affinity. Concentrations of potassium ions antagonize the binding of both divalent cations, especially calcium.