USING LIPOATE ENANTIOMERS AND THIOREDOXIN TO STUDY THE MECHANISM OF THE 2-OXOACID-DEPENDENT DIHYDROLIPOATE PRODUCTION BY THE 2-OXOACID DEHYDROGENASE COMPLEXES
USING LIPOATE ENANTIOMERS AND THIOREDOXIN TO STUDY THE MECHANISM OF THE 2-OXOACID-DEPENDENT DIHYDROLIPOATE PRODUCTION BY THE 2-OXOACID DEHYDROGENASE COMPLEXES
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DOI：
10.1016/0014-5793(95)00904-n
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发表时间：
1995-09-04
期刊：
影响因子：
3.5
通讯作者：
FOLLMANN, H
中科院分区：
文献类型：
--
作者：
BUNIK, V;SHOUBNIKOVA, A;FOLLMANN, H
The thioredoxin-catalyzed insulin reduction by dihydrolipoate was applied to study the 2-oxoacid:lipoate oxidoreductase activity of 2-oxoacid dehydrogenase complexes, The enzymatic and non-enzymatic mechanisms of the transfer of reducing equivalents from the complexes to free lipoic acid (alpha-lipoic acid, 6,8-thiooctic acid) were distinguished using the high stereoselectivity of the complex enzymes to the R-enantiomer of lipoate, Unlike these enzymes, thioredoxin from E, coli exibited no stereoselectivity upon reduction,vith chemically obtained dihydrolipoate, However, coupled to the dihydrolipoate production by the dehydrogenase complexes, the process was essentially sensitive both to the enantiomer used and the dihydrolipoyl dehydrogenase activity of the complexes, These results indicated the involvement of the third complex component, dihydrolipoyl dehydrogenase, in the 2-oxoacid-dependent dihydrolipoate formation, The implication of the investigated reaction for a connection between thioredoxin and the 2-oxoacid dehydrogenase complexes in the mitochondrial metabolism are discussed.
