S100 calcium-binding protein (S100) (S100)

The S100 calcium-binding protein (S100) family consists of over 20 low-molecular-weight proteins characterized by two EF-hand calcium-binding motifs (Source: UniProt). These proteins function as dynamic calcium sensors that undergo conformational changes upon binding calcium, allowing them to interact with various target proteins to regulate cell cycle progression, differentiation, and motility (Source: PubMed). Beyond their intracellular roles, several S100 members are secreted and function as damage-associated molecular patterns (DAMPs), activating the Receptor for Advanced Glycation End-products (RAGE) and Toll-like receptor 4 (TLR4) to initiate inflammatory cascades (Source: NIH). Clinically, S100 proteins are significant as both therapeutic targets and diagnostic biomarkers; for instance, S100B is an established marker for melanoma and traumatic brain injury (Source: StatPearls). Therapeutic strategies involve small molecule inhibitors like tasquinimod, which targets S100A9 to treat prostate cancer, and pentamidine, which inhibits S100B (Source: PubChem). However, the high structural homology between family members presents a challenge for achieving isoform-specific inhibition without off-target effects (Source: Wikipedia).

Other names

S-100 proteinS100 proteinsEF-hand calcium-binding proteinCalgranulinCalprotectin (S100A8/A9 complex)

Inhibition of calcium-dependent protein-protein interactions and antagonism of extracellular signaling through RAGE and TLR4 receptors.