S100, S-100 protein alpha subunit, S-100 protein alpha chain, Protein S100-A1, S100 calcium-binding protein A1, S100 alpha, Protein S100-A1, S-100 protein alpha chain, S-100 protein subunit alpha, S100 Calcium Binding Protein A1, S100 calcium-binding protein A1, S100 protein alpha polypeptide, S100A, S10A1_HUMAN, S-100 alpha, S-100-alpha, S-100alpha.
Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites.