Inhibition of D(--)-beta-hydroxybutyrate dehydrogenase by modifiers of disulfides, thiols, and vicinal dithiols.
Inhibition of D(--)-beta-hydroxybutyrate dehydrogenase by modifiers of disulfides, thiols, and vicinal dithiols.
复制标题
二硫化物、硫醇和邻二硫醇修饰剂对 D(--)-β-羟基丁酸脱氢酶的抑制。
DOI：
10.1021/bi00506a001
复制
发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
Hatefi,Y
中科院分区：
文献类型：
--
作者：
Phelps,DC;Hatefi,Y
Donna C. Phelps1 和 Youssef Hatefi* 摘要：牛心线粒体的 o (-)-/3-羟基丁酸脱氢酶在 NAD 存在下催化 D-(-)-/3-羟基丁酸可逆氧化为乙酰乙酸。酶的膜结合形式和可溶形式均受到硫醇修饰剂[N-乙基马来酰亚胺（NEM）和对（氯汞）苯磺酸盐（pCMS）]、邻位二硫醇[氧化苯胂和二氮烯二甲酸双（二甲酰胺）（二酰胺）]和二硫化物（亚硫酸盐、硫化物和氰化物）的抑制。 NAD 和 NADH，但不包括 3-羟基丁酸和乙酰乙酸，可以保护酶免受 NEM、pCMS、氧化苯胂和二酰胺的抑制。用 NEM 和二酰胺进行测试，单硫醇和二硫醇修饰剂引起的抑制是伪一级，并且 D (-)-/3-羟基丁酸脱氢酶 (EC 1.1.1.30) 首次由 Green 等人 (1937) 于 1937 年发现，并由 Sekuzuet al.(1963) 首先以高度纯化的形式分离出来。/3-羟基丁酸脱氢酶紧密结合线粒体内膜（Grafflin & Green，1948；Cheldelin & Beinert，1952；Lehninger & Greville，1953），其催化位点显然面向线粒体基质（Gaudemer & Latruffe，1975）。它在 NAD 存在下催化立体异构体 o (-)-/3-羟基丁酸酯可逆氧化为乙酰乙酸酯。在肝外组织中，但在肝脏中则不然，乙酰乙酸通过琥珀酰辅酶A-乙酰乙酸硫代酶转化为乙酰乙酰辅酶A，然后进一步转化为乙酰辅酶A，并通过柠檬酸循环完全氧化。乙酰乙酰辅酶A的产生是由线粒体底物水平磷酸化反应的反应物和产物的质量作用效应通过调节琥珀酰辅酶A的水平来控制的（Hatefi
Donna C. Phelps1 and Youssef Hatefi* abstract: o (-)-/3-Hydroxybutyrate dehydrogenase of beef heart mitochondria catalyzes the reversible oxidation of D-(-)-/3-hydroxybutyrate toacetoacetate in the presence of NAD. Both the membrane-bound and the soluble forms of the en-zyme are inhibited by modifiers of thiols [iV-ethylmaleimide (NEM) and p-(chloromercuri) phenylsulfonate (pCMS)], vicinal dithiols [phenylarsineoxide and diazenedicarboxylic acid bis (dimethylamide)(diamide)], and disulfides (sulfite, sulfide, and cyanide). NAD and NADH, but not/3-hydrox-ybutyrate and acetoacetate, protect the enzyme against in-hibition by NEM, pCMS, phenylarsine oxide, and diamide. As tested with NEM and diamide, the inhibitions caused by mono-and dithiol modifiers were pseudo first order, and theD (-)-/3-Hydroxybutyrate dehydrogenase (EC 1.1. 1.30) was first discovered in 1937 by Green et al.(1937) and first isolated in highly purified form by Sekuzuet al.(1963)./3-Hydrox-ybutyrate dehydrogenase is tightly bound to the inner mem-brane of mitochondria (Grafflin & Green, 1948; Cheldelin & Beinert, 1952; Lehninger & Greville, 1953), with its catalytic site apparently facing the mitochondrial matrix (Gaudemer & Latruffe, 1975). It catalyzes the reversible oxidation of the stereoisomer o (-)-/3-hydroxybutyrate to acetoacetate in the presence of NAD. In extrahepatic tissue, but not in liver, acetoacetate is converted to acetoacetyl-CoA by the enzyme succinyl-CoA-acetoacetate thiophorase and is then further converted to acetyl-CoA and completely oxidized through the citric acid cycle. The production of acetoacetyl-CoA is con-trolled by the mass action effect of the reactants and products of the substrate-level phosphorylation reactions of mitochondria through their modulation of the level of succinyl-CoA (Hatefi