On the dehydration of (R)‐lactate in the fermentation of alanine to propionate by Clostridium propionicum

FEBS Letters

Schweiger, Georg¹  Buckel, Wolfgang¹ 

[1] Biochemie I, Universität Regensburg, D-8400 Regensburg, FRG

关键词: (S)-Alanine;    (S)-Glutamate dehydrogenase (NAD);    (R)-Lactate dehydrogenase (NAD);    Propionate CoA-transferase;    (R)-Lactate dehydration;    Inhibition by 2;    4-dinitrophenol;   

DOI  :  10.1016/0014-5793(84)80463-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

All the enzymes of the pathway of (S)-alanine fermentation to acetate and propionate were detected in cell-free extracts of Clostridium propionicum. Among these (S)-glutamate dehydrogenase (NAD), (R)-lactate dehydrogenase (NAD) and propionate CoA-transferase were purified to apparent homogeneity. Their structures were presumably α₆, α₂ and α₄, respectively. The latter enzyme was specific for short-chain monocarboxylic acids with a pronounced preference for (R)-lactate over the (S)-enantiomer. The key step of the pathway, the dehydration of (R)-lactate required acetyl phosphate and CoASH under anaerobic conditions. It was inhibited by hydroxylamine, arsenate, azide (1 mM each) or by 0.1 mM 2,4-dinitrophenol. Thus it closely resembled the dehydration of (R)-2-hydroxyglutarate in Acidaminococcus fermentans, although an activation was not necessary.

【 授权许可】

Unknown