牛心线粒体ATP酶抑制蛋白对酶的催化部位构象的影响

以标记在ＡＴＰ酶（Ｆ_１）催化部位的ＴＮＰ－ＡＴＰ为荧光探针，比较测定了Ｆ_１与其抑制蛋白（ＩＦ_１）结合前后的ＴＮＰ－ＡＴＰ荧光光谱、荧光寿命和荧光偏振光谱。结果表明在ＩＦ１的作用下，酶分子催化部位的极性下降，ＴＮＰ－ＡＴＰ分子运动的自由度减小，提示ＩＦ_１引起了Ｆ_１催化部位的构象改变。

Regulatory Function of Mitochondrial ATPase Inhibitor Protein on Catalytic Portion of ATPase

The regulatory function of mitochondrial ATPase inhibitor (IF1) on catalytic portion of ATPase (F1) was investigated by using labelled F1 with fluorescent ATP derivatve 2’, 3’,-0(2, 4, 6-trinitrocyclohexadienylidene) adenosine 5’-triphosphate (TNP-ATP).The fluorescent parameters including fluorescent spectra, fluorescent lifetime and polarization spectra were determined for TNP-ATP-F1 and IF1-TNP-ATP-F1. These data indicate that IF1 significantly alters the polarity of the catalytic portion of F1 and the catalytic portion became more constricted under the action of IF1.