【正文】
e) Stage3:電子傳遞和氧化磷酸化 。 一些特殊化合物中,主要是 ATP。 ? 氧化脫羧反應由丙酮酸脫氫酶復合體(丙酮酸脫氫酶系)催化。 丙酮酸脫氫酶復合體 ( pyruvate dehydrogenase plex) Enzymes E1: pyruvate dehydrogenase 丙酮酸脫氫酶 E2: dihydrolipoyl transacetylase 二氫硫辛酸乙酰轉(zhuǎn)移酶 E3: dihydrolipoyl dehydrogenase 二氫硫辛酸脫氫酶 Coenzymes/prosthetic group TPP: thiamine pyrophosphate (焦磷酸硫胺素) FAD: flavin adenine dinucleotide (黃素腺嘌呤二核苷酸) CoA: coenzyme A(輔酶 A) NAD+: nicotinamide adenine dinucleotide (尼克酰胺腺嘌呤二核苷酸) Lipoate(硫辛酸) Dissociable proton Reactive carbon atom TPP as an acyl carrier H+ + e H+ + e H H 半醌型 FMN/FAD: electron carrier CoA as an acyl carrier NAD(P)+: electron carrier H+ + 2e H+ :H 硫辛酸結(jié)構(gòu) both as an acyl carrier and an electron carrier 丙酮酸脫氫酶復合體排列示意圖 A model of the E. coli pyruvate dehydrognase plex showing the three kinds of enzymes and the flexible lipoamide arms covalently attached to E2 E2 (dihydrolipoyl transacetylase): consisting the core, 24 subunits。 E3 (dihydrolipoyl dehydrogenase): bound to the E2 core, 12 subunits. (a protein kinase and Protein kinase and phosphoprotein phosphatase, not shown here, are also part of the plex) E2 E3 Electron micrograph of pyruvate dehydrogenase plexes from E. coli ? 氧化脫羧反應過程經(jīng)過 5步反應: 丙酮酸脫氫酶復合體的作用 ? 丙酮酸脫氫酶復合體的反應機制精巧而又復雜。 ? 任何引起丙酮酸脫氫酶功能異常的因素都會導