Na_2SO_3和NaHCO_3对叶绿体CF_1－ATPase活力作用的机制  

Mechanism of Stimulation of Chloroplast ATPase by Sulfite and Bicarbonate

作　　者：何向东 杜子云[1] 李有则[1] 

机构地区：[1]中国科学院上海植物生理研究所

出　　处：《植物生理学报（0257-4829)》1995年第2期175-182,共8页Acta Phytophysiologica Sinica

基　　金：国家自然科学基金

摘　　要：Ｎａ２ＳＯ３对热－ＤＴＴ活化的游离ＣＦ１及类囊体膜上ＣＦ１－ＡＴＰａｓｅ活力均有显著的促进作用，ＮａＨＣＯ３亦有明显的促进作用。Ｎａ２ＳＯ３和ＮａＨＣＯ３的促进作用与它们解除Ｍｇ２＋的抑制作用有关。从ＮａＨＣＯ３和Ｎａ２ＳＯ３及它们与Ｍｇ２＋之间的竞争性关系，表明三者是结合在酶的同一部位上。Ｎａ２ＳＯ３可明显降低热－ＤＴＴ活化的游禹ＣＦ１－ＡＴＰａｓｅ催化反应的活化能，这可能与促进产物ＡＤＰ的释放有关。Sulfite markedly stimulated the ATPase activity of both heat-DTT activated soluble and thylakoid membrane-bound CF1. Similar to sulfite,bicarbonate also significantly stimulated the ATPase activity of soluble CF1,but showed barely visible effects on that of membrane-bound CF1 (Figs. 1,2 ). The stimulatory effects of sulfite and bicarbonate were found to be related with their role in relieving Mg2+ inhibition (Table 1). The competitive character of the inhibition by sulfite,bicarbonate and Mg2+ indicated that they might bind to the same site on the enzyme (Figs. 3￣6 ). The activation energy of the catalytic reaction of soluble CF1-ATPase activated by heat-DTT could be decreased markedly by sulfite (Fig. 7), it might be correlated with its stimulatory effect on ADP release.

关 键 词：亚硫酸钠 碳酸氨钠 叶绿体 CF1 腺苷三磷酸酶 

分 类 号：Q732[生物学—分子生物学]