S100b also known as Protein S100-B. S100b is a protein of the S100 protein family. S100 proteins comprise a multigene family of EF-hand calcium binding proteins that engage in multiple functions in response to cellular stress. S100b protein has been implicated in oligodendrocyte progenitor cell (OPC) regeneration in response to demyelinating insult. Also, S100b and other members of S100 proteins are specifically interact with PP5-TPR and inhibited the PP5-Hsp90 interaction. Recombinant mouse S100b was expressed in E.coli and purified by using conventional chromatography techniques.