Norling B, Tourikas C, Hamasur B, Glaser E
Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden.
Eur J Biochem. 1990 Mar 10;188(2):247-52. doi: 10.1111/j.1432-1033.1990.tb15396.x.
An endogenous ATPase inhibitor protein has been identified and isolated for the first time from plant mitochondria. The inhibitor protein was isolated from potato (Solanum tuberosum) tuber mitochondria and purified to homogeneity. The isolated inhibitor is a heat-stable, trypsin-sensitive, basic protein, with a molecular mass approximately 8.3 kDa. Amino acid analysis reveals a high content of glutamic acid, lysine and arginine and the absence of proline; threonine and leucine. The interaction of the inhibitor with F1-ATPase requires the presence of Mg2(+)-ATP in the incubation medium. The ATPase activity of isolated F1 is inhibited to 50% in the presence of 14 micrograms inhibitor/mg F1. A stoichiometry of 1.3 mol inhibitor/mol F1 for complete inhibition can be calculated from this value. The potato ATPase inhibitor is also a potent inhibitor of the ATPase activity of the isolated yeast F1. The inhibitor resembles the ATPase inhibitors of yeast and mammalian mitochondria, and does not seem to be related to the inhibitory peptide, epsilon subunit, of chloroplast ATPase.
首次从植物线粒体中鉴定并分离出一种内源性ATP酶抑制剂蛋白。该抑制剂蛋白是从马铃薯（Solanum tuberosum）块茎线粒体中分离出来的，并纯化至同质。分离出的抑制剂是一种热稳定、对胰蛋白酶敏感的碱性蛋白，分子量约为8.3 kDa。氨基酸分析显示谷氨酸、赖氨酸和精氨酸含量高，且不含脯氨酸、苏氨酸和亮氨酸。抑制剂与F1-ATP酶的相互作用需要在孵育介质中存在Mg2(+)-ATP。在存在14微克抑制剂/毫克F1的情况下，分离出的F1的ATP酶活性被抑制50%。据此值可计算出完全抑制所需的抑制剂与F1的化学计量比为1.3摩尔抑制剂/摩尔F1。马铃薯ATP酶抑制剂也是分离出的酵母F1的ATP酶活性的有效抑制剂。该抑制剂类似于酵母和哺乳动物线粒体的ATP酶抑制剂，似乎与叶绿体ATP酶的抑制肽ε亚基无关。
