Polypeptide-chain stoicheiometry and lipoic acid content of the pyruvate dehydrogenase complex of Escherichia coli.
Polypeptide-chain stoicheiometry and lipoic acid content of the pyruvate dehydrogenase complex of Escherichia coli.
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大肠杆菌丙酮酸脱氢酶复合物的多肽链化学计量和硫辛酸含量。
DOI：
10.1042/bj1770129
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
R. Perham
中科院分区：
文献类型：
--
作者：
G. Hale;R. Perham
丙酮酸脱氢酶多酶复合体是从[35S]硫酸盐存在下生长的大肠杆菌中分离出来的。用十二烷基硫酸钠/聚丙烯酰胺凝胶电泳法分离三种多肽链，通过测定各区带的放射性来确定三种多肽链的摩尔比。硫胺脱氢酶与硫辛酸酯乙酰转移酶的链比接近1，但丙酮酸脱羧酶的链摩尔过剩。35S标记的络合物还用于硫辛酸总含量的新测定。研究发现，脂肪酸乙酰转移酶组分的每个多肽链似乎至少含有三个硫辛基。
The pyruvate dehydrogenase multienzyme complex was isolated from Escherichia coli grown in the presence of [35S]sulphate. The three component enzymes were separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and the molar ratios of the three polypeptide chains were determined by measurement of the radioactivity in each band. The chain ratio of lipoamide dehydrogenase to lipoate acetyltransferase approached unity, but there was a molar excess of chains of the pyruvate decarboxylase component. The 35S-labelled complex was also used in a new determination of the total lipoic acid content. It was found that each polypeptide chain of the lipoate acetyltransferase component appears to bear at least three lipoyl groups.