Zimmer Danna B, Weber David J
Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A & M University, MS 4467 College Station, TX 77843-4467, USA.
Cardiovasc Psychiatry Neurol. 2010;2010. doi: 10.1155/2010/728052. Epub 2010 Aug 17.
S100B is a calcium signaling protein that is a member of the S100 protein family. An important feature of S100B and most other S100 proteins (S100s) is that they often bind Ca(2+) ions relatively weakly in the absence of a protein target; upon binding their target proteins, Ca(2+)-binding then increases by as much as from 200- to 400-fold. This manuscript reviews the structural basis and physiological significance of increased Ca(2+)-binding affinity in the presence of protein targets. New information regarding redundancy among family members and the structural domains that mediate the interaction of S100B, and other S100s, with their targets is also presented. It is the diversity among individual S100s, the protein targets that they interact with, and the Ca(2+) dependency of these protein-protein interactions that allow S100s to transduce changes in Ca(2+) levels into spatially and temporally unique biological responses.
S100B是一种钙信号蛋白，属于S100蛋白家族。S100B和大多数其他S100蛋白（S100s）的一个重要特征是，在没有蛋白质靶点的情况下，它们通常与Ca(2+)离子结合相对较弱；一旦与它们的靶蛋白结合，Ca(2+)结合能力随后会增加多达200至400倍。本文综述了在存在蛋白质靶点的情况下Ca(2+)结合亲和力增加的结构基础和生理意义。还介绍了有关家族成员之间冗余以及介导S100B和其他S100s与其靶点相互作用的结构域的新信息。正是单个S100s之间的多样性、它们与之相互作用的蛋白质靶点以及这些蛋白质-蛋白质相互作用对Ca(2+)的依赖性，使得S100s能够将[Ca(2+)]（细胞内）水平的变化转化为空间和时间上独特的生物学反应。
