Na_2SO_3对不同状态CF_1－ATPase活力的促进作用  

Study on the Stimulative Effect of Sulfite on the Activity of CF_1-ATPase in Different States

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)》1996年第3期303-310,共8页Acta Phytophysiologica Sinica

基　　金：国家自然科学基金

摘　　要：Ｎａ２ＳＯ３对ＣＦ１－ＡＴＰａｓｅ活力的促进作用与酶所处状态有关。ＣＦ０降低ＣＦ１对Ｎａ２ＳＯ３的亲和力和Ｎａ２ＳＯ３促进的最大反应速率。在Ｎａ２ＳＯ３作用下，膜上ＣＦ１－ＡＴＰａｓｅ的活化能高于游离的。膜上和游离ＣＦ１－ＡＴＰａｓｅ的γ亚基上二硫键的还原可以提高Ｎａ２ＳＯ３对酶活力的促进作用。Ｎａ２ＳＯ３对甲醇活化的ＣＦ１－ＡＴＰａｓｅ活力的促进作用只有在甲醇活化的亚适浓度下才能充分表现出来。Ｎａ２ＳＯ３对Ｍｇ２＋抑制的解除作用因ＣＦ１－ＡＴＰａｓｅ处于不同活化状态而不同。The effects of sulfite on CF1ATPase in different binding saltes and activated by different methods were studied. Sulfite stimulated the activity ofheat/DTT-activated soluble and thylakoid membrane-bound CF1-ATPase,but the stimulative effect on membranebound CF1-ATPase activity was weaker(Fig. 1 ). The affinity of heat/DTT-activated membrane-bound CF1-ATPasefor sulfite and the maximal activity ofheat/DTT-activated membrane-boundCF1-ATPase stimulated by sulfite werelower than those of soluble CF1-ATPase(Table 1 ). In the presence of sulfite,the activation energy of thylakoid membrane-bound CF1-ATPase was higherthan that of soluble CF1-ATPase (Fig.2 ). These results indicate that thecatulytic function of CF1 is controlledby membrane-bound CF0.The reduction of disulfide bond inY subunit could further increase thestimulative effect of sulfite on heat-ormethanol-activated soluble and thylakoid-membrane-bound CF1-ATPase(Fibs. 3-5).The stimulative effect of sulfite onthe methanol-activated soluble and thylakoid membrane-bound CF1-ATPasewas dependent on the methanol concentration in the reaction medium. Itsstimulative effect was more pronouncedat sub-optimal methanol concentrationsthan at the optimum concentration (Fig.6 ). The relieving effect of sulfite onthe inhibition of the methanol-activatedCF1-ATPase activity by Mg2+ was different from that of the heat/Drr-activated CF1-Accuse (Fig. 7). Why sulfite has different effects in relieving theinhibition of the activity of differentlyactivated CF1-ATPase by Mg2+ needsfurther study.

关 键 词：叶绿体 腺苷三磷酸酶 酶活力 亚硫酸钠 

分 类 号：Q732[生物学—分子生物学]