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猪心线粒体F_1—ATP酶分子组成中约有97个酪氨酸残基,其中相当一部份是暴露的,有约10个左右的色氨酸残基埋藏于分子内部的疏水区。采用不同链长以及不同分支链的甲、乙、正丙、异丙和叔丁五种醇作用于猪心线粒体F_1—ATP酶,观察此酶水解活性变化的同时观察其内源荧光的变化以及用ANS荧光探针观察其疏水区的变化。实验结果指出,当F_1受不同浓度(5％—20％)甲醇作用后其水解活性呈激活状态。这时F_1的内源酪氨酸的荧光增强,这可能是由于F_1分子中酪氨酸残基的暴露有所增加或由于分子二、三、四级的结构有所变化,这后者的构象变化减弱了酪氨酸荧光的猝灭所致。至于对ANS荧光的影响则呈下降现象。当F_1受乙醇、正丙醇、异丙醇或叔丁醇作用后水解活性呈抑制作用时F_1分子中内源色氨酸荧光大为增加。这意味着色氨酸的暴露疏水区的扩大,ANS疏水荧光探针监测的结果与此一致,也是疏水区的扩大。文中对F_1激活与抑制时两种不同构象作了初步介释。
There are about 97 tyrosine residues in the molecular composition of porcine heart mitochondrial F_1-ATPase, a considerable portion of which is exposed. About 10 tryptophan residues are buried in the hydrophobic region inside the molecule. The mitochondrial F 1 -ATPase activity of porcine heart mitochondrial F_1-ATPase was tested by using five kinds of alcohols (A, B, C, C and F) with different chain lengths and branches. The change of endogenous fluorescence The ANS fluorescence probe was used to observe the change of hydrophobic region. The experimental results indicated that when F_1 was exposed to different concentrations of methanol (5% -20%), its hydrolytic activity was activated. At this time F 1 endogenous tyrosine fluorescence increased, which may be due to F 1 molecules tyrosine residue increased exposure or due to the molecular structure of two, three, four changes, the latter conformation Changes diminish the quenching of tyrosine fluorescence. As for the impact of ANS fluorescence decreased. When F_1 was inhibited by ethanol, n-propanol, isopropanol or tert-butanol, the endogenous tryptophan fluorescence in F_1 molecule was greatly increased. This means that the enlarged hydrophobic region of tryptophan exposed, ANS hydrophobic fluorescent probe monitoring results consistent with this, but also the expansion of the hydrophobic region. In this paper, two different conformations of F_1 activation and repression were preliminarily explained.