Inhibition of D (-)-3-hydroxybutyrate dehydrogenase by malonate analoges.
Inhibition of D (-)-3-hydroxybutyrate dehydrogenase by malonate analoges.
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丙二酸类似物抑制 D (-)-3-羟基丁酸脱氢酶。
DOI：
10.1016/0003-9861(75)90376-8
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发表时间：
1975
影响因子：
3.9
通讯作者：
G. Plaut
中科院分区：
文献类型：
--
作者：
A. W. Tan;C. Smith;T. Aogaichi;G. Plaut
来自豚鼠、大鼠和牛心脏以及豚鼠肝脏的 (1)d(-)-3-羟基丁酸脱氢酶活性被丙二酸和酒石酸抑制，并且更有效地被类似物丙二酸甲酯、溴丙二酸、氯代丙二酸和中草酸抑制。发现对氨基丙二酸、丙二酸乙酯、丙二酸二甲酯、琥珀酸、戊二酸、草酰乙酸、苹果酸、丙酸、丙酮酸、d-和l-乳酸、正丁酸、异丁酸和环丙烷甲酸的抑制作用很小或没有。 (2) 在 pH 8.1 的初始速度动力学中，使用来自牛心脏的可溶性酶制剂，活性丙二酸衍生物的抑制作用与 3-羟基丁酸具有竞争性，而与乙酰乙酸、NAD+ 或 NADH 没有竞争性。以d-3-羟基丁酸作为可变反应物(Kmapp=0.26mM)，丙二酸甲酯的抑制常数(Kis)为0.09mm。 (3)在ADP存在下，偶联的大鼠心脏线粒体对d-3-羟基丁酸(78μm)的利用率被150μm甲基丙二酸抑制50%。 (4) 在不添加 ADP 的情况下，在豚鼠肝脏线粒体氧化正辛酸的情况下，丙二酸甲酯 (1-3 mm) 对 3-羟基丁酸形成的抑制作用远大于对总酮产生的抑制作用。然而，添加甲基丙二酸后，线粒体内NADH（或NADPH）水平没有变化，表明积累的3-羟基丁酸和乙酰乙酸的比率的变化是由3-羟基丁酸脱氢酶的直接抑制引起的。以丙酮酸或乙酸酯作为乙酰基源，丙二酸甲酯对 3-羟基丁酸/乙酰乙酸酯比例和酮体形成具有相同的影响。尽管辛酸对总酮形成的抑制更为严重，但丙二酸（10 mm）也获得了类似的结果。
(1)d(-)-3-Hydroxybutyrate dehydrogenase activity from guinea pig, rat, and bovine heart and from guinea pig liver is inhibited by malonate and tartronate, and more potently by the analogs methylmalonate, bromomalonate, chloromalonate, and mesoxalate. Little or no inhibitory effect was found for aminomalonate, ethylmalonate, dimethylmalonate, succinate, glutarate, oxaloacetate, malate, propionate, pyruvate,d- andl-lactate,n-butyrate, isobutyrate, and cyclopropanecarboxylate. (2) In initial velocity kinetics at pH 8.1 with a soluble enzyme preparation from bovine heart, the inhibition by the active malonate derivatives is competitive with respect to 3-hydroxybutyrate and uncompetitive with respect to acetoacetate, NAD+or NADH. Withd-3-hydroxybutyrate as the variable reactant (Kmapp= 0.26 mM) the inhibition constant of methylmalonate (Kis) was 0.09 mm. (3) The rate of utilization ofd-3-hydroxybutyrate (78 μm) by coupled rat heart mitochondria in the presence of ADP was inhibited 50% by 150 μmmethylmalonate. (4) With coupled guinea pig liver mitochondria oxidizingn-octanoate in the absence of added ADP, methylmalonate (1–3 mm) depressed 3-hydroxybutyrate formation substantially more than total ketone production. However, the intramitochondrial NADH (or NADPH) levels were unchanged by the addition of methylmalonate, indicating that the changes in ratios of accumulated 3-hydroxybutyrate and acetoacetate were caused by direct inhibition of 3-hydroxybutyrate dehydrogenase. Methylmalonate had the same effect on 3-hydroxybutyrate/acetoacetate ratios and ketone body formation with pyruvate or acetate as the source of acetyl groups. Similar results were obtained with malonate (10 mm) although the inhibition of total ketone formation from octanoate was more severe.