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玉米细胞质分子伴侣Hsp70的ATPase活性

周人纲, Miernyk J A

河北省农林科学院农业物理生理生化研究所.河北,石家庄 050051；Micotoxin Research Unit,USDA,National Center for Agricultural Utilization Research.Peoria,IL 61604

摘要

玉米胚乳细胞中纯化的细胞质Hsp70蛋白有低水平的ATPase活性,它在50℃、pH5.8、20mmol/L的KCl条件下活性最高,Ca~(2+)和Mg~(2+)抑制其活性。大肠杆菌DnaJ蛋白能将玉米细胞质Hsp70的ATPase活性提高6倍,而GrpE蛋白对其影响很小。8种不同的人工合成多肽均能刺激该蛋白的ATPase活性,增加幅度从2.5倍到10倍不等。亲水性不同的氨基酸对Hsp70的ATPase活性影响不同。玉米细胞质Hsp70是一个三磷酸核苷酸酶,除ATP外,它还能催化UTP、GTP、CTP和ITP的水解。

关键词： 热激蛋白; 分子伴侣; ATPase活性; 玉米

ATPase activity of cytosolic chaperone Hsp70 from maize endosperm cell

Zhou Rengang, Miernyk J A

Institute of Agro-physics,Physiology and Biochemistry,Hebei Academy of Agricultural Sciences.Shijiazhuang 050051,Hebei

Abstract

The cytosolic chaperone Hsp70 protein from maize endosperm cell was purified. The Hsp70 have a low-level ATPase activity at normal temperature. In vitro the ATPase activity of the Hsp70 was maximal at 50℃, pH 5.8, and a KCl concentration of 20 mmol/L. It^s activity was decreased with increasing concentration of magnesium or calcium from 0 to 20 mmol/L. The co-chaperone protein from E. coli, DnaJ protein, increased the ATPase activity of maize Hsp70 about 6-fold, while GrpE, also a co-chaperone protein from E. coli, had no effect.

Key words: Heat shock protein;Molecular chaperone;ATPase activity;maize (Zea mays L.)

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引用本文：

周人纲, Miernyk J A. 玉米细胞质分子伴侣Hsp70的ATPase活性[J]. 生理学报 1999; 51 (3): .

Zhou Rengang, Miernyk J A. ATPase activity of cytosolic chaperone Hsp70 from maize endosperm cell. Acta Physiol Sin 1999; 51 (3): (in Chinese with English abstract).