S100蛋白对猪脑微管蛋白中微管蛋白依赖性ATP酶活性的抑制作用。

Inhibition of tubulin-dependent ATPase activity in microtubule proteins from porcine brain by S100 protein.

作者信息

Asai H, Miyasaka Y, Kondo Y, Fuju T

机构信息

Department of Functional Polymer Science, Faculty of Textile Science and Technology, Shinshu University, Ueda 386, Japan.

出版信息

Neurochem Int. 1988;13(4):509-16. doi: 10.1016/0197-0186(88)90082-4.

DOI:10.1016/0197-0186(88)90082-4

PMID:20501311

Abstract

Microtubule-associated proteins (MAPs) of brain microtubules exhibit an ATPase activity which is markedly enhanced by tubulin and Ca(2+). Addition of S100 protein decreased the tubulindependent Ca(2+)-ATPase activity by about 85%, but did not affect the activity without tubulin. The inhibition by S100 protein was concentration-dependent and the apparent K(m) value for ATP was not altered. A large amount of tubulin restored the inhibition, indicating that S100 protein acts through the binding to the tubulin molecule. Zn(2+), which can bind both microtubule proteins and S100 protein, had little effect on the inhibitory action of S100 protein. The ATPase inhibition by S100 protein was partially restored by chlorpromazine or vinblastine. S100a is more effective than S100b on the inhibitory effect of tubulin-dependent ATPase activity. The results suggest that S100 protein may function as a regulatory factor of ATPase in brain microtubules.

摘要

脑微管的微管相关蛋白（MAPs）表现出一种ATP酶活性，该活性可被微管蛋白和Ca(2+)显著增强。添加S100蛋白可使依赖微管蛋白的Ca(2+)-ATP酶活性降低约85%，但不影响无微管蛋白时的活性。S100蛋白的抑制作用呈浓度依赖性，且ATP的表观K(m)值未改变。大量微管蛋白可恢复这种抑制作用，表明S100蛋白通过与微管蛋白分子结合发挥作用。既能结合微管蛋白又能结合S100蛋白的Zn(2+)对S100蛋白的抑制作用影响很小。氯丙嗪或长春花碱可部分恢复S100蛋白对ATP酶的抑制作用。S100a对依赖微管蛋白的ATP酶活性的抑制作用比S100b更有效。结果表明，S100蛋白可能作为脑微管中ATP酶的调节因子发挥作用。