title: Zinc ion binding to human brain calcium binding proteins, calmodulin and S100b protein.
abstract: Comparative studies have been performed on the binding properties of zinc ions to human brain calmodulin and S100b protein. Calmodulin is characterized by two sets of Zn2+ binding sites, with KD ranging from 8.10(-5)M to 3.10(-4)M. The S100b protein also exhibited two sets of zinc binding sites, with a much higher affinity. KD = 10(-7) - 10(-6)M. We suggest that S100b protein should no longer be considered only as a "calcium binding protein" but also as a "zinc binding protein", and that Zn2+ ions are involved in the functions of the S100 proteins.
mesh_terms: D001921:Brain / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009418:S100 Proteins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D014443:Tyrosine; D015032:Zinc / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D009419:Nerve Tissue Proteins; D009418:S100 Proteins; D014443:Tyrosine; D015032:Zinc