Impairment of pyruvate dehydrogenase activity by acetaldehyde
Impairment of pyruvate dehydrogenase activity by acetaldehyde
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DOI：
10.1016/s0741-8329(01)00156-2
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发表时间：
2001-08-01
期刊：
影响因子：
2.3
通讯作者：
Koren, G
中科院分区：
文献类型：
--
作者：
Hard, ML;Raha, S;Koren, G
胎儿酒精综合征（FAS）的面部特征与丙酮酸脱氢酶（PDH）缺乏症的面部特征惊人相似。此外，酒精诱导的中枢神经系统损伤导致中线异常，如胼胝体发育不全，这也被描述在几种代谢疾病，包括PDH缺乏症。本工作的目的是检查乙醛对PDH的影响在体外。在乙醛（10 μ M-1 mM）存在下，通过在340 nm处测量还原形式的烟酰胺-腺嘌呤二核苷酸的形成来测量PDH的活性。丙酮酸脱氢酶与[1，2-C-14]-乙醛孵育后，用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳技术分离，以放射自显影检测共价加合物的形成。乙醛对磷酸化的复合物的效果，也确定了自显影孵育后的PDH与P-32-腺苷三磷酸。该研究的结果表明，乙醛通过混合抑制型机制（Kic = 62.4 +/- 25.7 μ M，Kiu = 225 +/- 68 μ M）损害PDH活性，这不是与PDH形成共价加合物的结果，也不是复合物的磷酸化或失活的刺激的结果。由于PDH水平在整个发展过程中是低的，丙酮酸和乙醛之间的竞争可能会增强，由于乙醇诱导的环境丙酮酸浓度的降低，我们得出结论，PDH的损害可能有显着的影响发育中的胎儿。(C)2001 Elsevier Science Inc. All rights reserved.
The facial features that are characteristic of fetal alcohol syndrome (FAS) are strikingly similar to those seen in pyruvate dehydrogenase (PDH) deficiency. Furthermore, alcohol-induced central nervous system insult results in midline anomalies such as agenesis of the corpus callosum, which has also been described in several metabolic diseases, including PDH deficiency. The purpose of this work was to examine the effect of acetaldehyde on PDH in vitro. The activity of PDH was measured in the presence of acetaldehyde (10 muM-1 mM) by measuring the formation of the reduced form of nicotinamide-adenine dinucleotide at 340 nm. Pyruvate dehydrogenase was separated by using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique after incubation with [1,2-C-14]-acetaldehyde to detect the formation of covalent adducts autoradiographically. The effect of acetaldehyde on the phosphorylation of the complex was also determined autoradiographically after incubating of PDH with P-32-adenosine triphosphate. The results of this study show that acetaldehyde impairs PDH activity by a mixed inhibition type mechanism (Kic = 62.4 +/- 25.7 muM, Kiu = 225 +/- 68 muM), which is not a result of the formation of covalent adducts with PDH, nor of a stimulation of phosphorylation or inactivation of the complex. Because PDH levels are low throughout development and that the competition between pyruvate and acetaldehyde may be enhanced due to ethanol-induced lowering of ambient pyruvate concentrations, we conclude that impairment of PDH may have a significant effect on the developing fetus. (C) 2001 Elsevier Science Inc. All rights reserved.