S-100 proteins.

摘要: S-100 is a group of closely related, small, acidic Ca2+-binding proteins (S-100a0, S-100a and S-100b, which are alpha alpha, beta, beta in composition, respectively). structurally related to calmodulin other proteins. abundant the brain contained well defined cell types both neuroectodermal non-neuroectodermal origin, as their neoplastic counterparts. In mammalian brain, S-100b confined glial cells, while S-100a0 neuronal localization. Single isoforms bind Ca2+ with nearly same affinity. K+ antagonizes binding high affinity sites on S-100. binds Zn2+ found soluble membrane-bound form has ability interact artificial natural membranes. no enzymatic activity. been involved several activities including memory processes, regulation diffusion monovalent cations across membranes, modulation physical state phosphorylation proteins, control assembly-disassembly microtubules. Some these effects strictly Ca2+-dependent, not. being secreted or released extracellular space. some cases, this event hormonally regulated. Several described.