Moustafa E, Leong C K
Biochim Biophys Acta. 1975 May 23;391(1):9-14. doi: 10.1016/0005-2744(75)90146-1.
ATP, ADP, AMP and cyclic AMP inhibit NAD-dependent isocitrate dehydrogenase (L-s-isocitrate : NAD-+ oxidoreductase, EC 1.1.1.41) from rhizobia but have no effect on the enzyme from corresponding bacteroids. This was observed using three rhizobial strains two of which are effective, and one ineffective, with Lotus pedunculatus. Using partially purified enzyme from each of the three rhizobial strains it was found that the adenine nucleotides inhibit the enzyme by competing with NAD-+, not with isocritrate. The rate of reaction catalysed by the enzyme (expressed as activity per mg protein) in cell-free extracts of each of the effective rhizobial strains was about three times that of the reaction in extracts of the corresponding bacteroids. No correlation was found between effectiveness and NAD-dependent isocitrate dehydrogenase activity in the rhizobial cells.
ATP、ADP、AMP和环磷酸腺苷抑制根瘤菌中依赖NAD的异柠檬酸脱氢酶（L - s - 异柠檬酸：NAD⁺氧化还原酶，EC 1.1.1.41），但对相应类菌体中的该酶没有影响。这一现象是在使用三株根瘤菌菌株时观察到的，其中两株对百脉根有效，一株无效。使用从这三株根瘤菌菌株中部分纯化得到的酶发现，腺嘌呤核苷酸通过与NAD⁺竞争而非与异柠檬酸竞争来抑制该酶。在每株有效根瘤菌菌株的无细胞提取物中，该酶催化的反应速率（以每毫克蛋白质的活性表示）约为相应类菌体提取物中反应速率的三倍。在根瘤菌细胞中，有效性与依赖NAD的异柠檬酸脱氢酶活性之间未发现相关性。
