Mechanism of H^+ transport by H^+ATPase

H^+-ATP酶与ATP水解的能量耦合转运质子，ATP合成酶与质子运动耦合合成ATP。它们是生物体中最重要的两种基本酶。本课题主要研究了FoF_1型ATP酶和液泡型ATP酶，通过大量的诱变研究，发现β亚基的Lys-155、Thr-156、Glu-181和Arg-182都形成了ATP酶的催化位点。我们还可以表明，Glu-185的亚基是必不可少的催化协同性的酶。γ亚基的羧基和氨基末端螺旋是催化和质子传递之间能量耦合的关键，Fo的H^+通路由a、B和c亚基组成，我们可以发现a亚基有六个跨膜结构域，整个Fo具有环状结构。本文研究了一系列亲脂性阳离子对FoF_1-ATPase和液泡型ATPase的影响，并发现氯丙嗪、奎纳克林对这两种酶均有抑制作用。我们还发现，concanamycin对空泡型ATP酶的抑制作用。

H^+-ATPase transport protons coupling with the energy of ATP hydrosis, and ATP synthase synthesizes ATP coupling with proton movement. They are the two of the most the important basic enzymes in organisms. In this project, we have focused on FoF_1 type ATPase and vacuolar type ATPases.From the extensive mutagenesis studies, we could show Lys-155, Thr-156, Glu-181 and Arg-182 of the beta subunit are forming catalytic site. We also could show that Glu-185 of the subunit is essential for the catalytic cooperativity of the enzyme. The carboxyl and amino terminal helices of the gamma subunit were shown to be essential for energy coupling between catalysis and proton transport.The H^+ pathway of Fo is formed from the a, b, and c subunits we could show that the a subunit has six transmembrane domains and the entire Fo has a ring like structure. We have studied effects of a series of lipophilic cations on FoF_1-ATPase and vacuolar type ATPase and chloropromazine, quinacrine could in habit both enzymes. We also showed inhibitory effects of concanamycin on vacuolar type ATPase.