丽蝇飞行肌线粒体中腺嘌呤核苷酸的变化

Changes in intramitochondrial adenine nucleotides in blowfly flight-muscle mitochondria.

作者信息

Danks S M, Chappell J B

出版信息

Biochem J. 1974 Aug;142(2):353-8. doi: 10.1042/bj1420353.

DOI:10.1042/bj1420353

PMID:4374197

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1168286/

Abstract

With freshly isolated blowfly mitochondria 38% of the intramitochondrial adenine nucleotide was present as AMP. 2. On incubation with oxidizable substrates the AMP and ADP concentrations fell and that of ATP rose; with pyruvate together with proline the ATP concentration reached its maximum value at 6min; with glycerol phosphate the phosphorylation of endogenous nucleotide was more rapid. 3. Addition of the uncoupling agent carbonyl cyanide phenylhydrazone caused a rapid fall of ATP and a parallel rise in ADP, then ADP was converted into AMP. 4. This was in contrast with rat liver mitochondria endogenous AMP concentrations, which were always lower than those of blowfly mitochondria and changed little under different metabolic conditions. 5. Evidence is presented that adenylate kinase (EC 2.7.4.3) has a dual distribution in blowfly mitochondria, a part being located in the matrix space and a part in the space between the outer and inner mitochondrial membranes, as in liver and other mitochondria. 6. The possible regulatory role of changing AMP concentrations in the mitochondrial matrix was investigated. Partially purified pyruvate carboxylase (EC 6.4.1.1) and citrate synthase (EC 4.1.3.7) were inhibited 30% by 2mm-AMP, whereas pyruvate dehydrogenase (EC 1.2.4.1) was unaffected. 7. AMP activated the NAD(+)-linked isocitrate dehydrogenase (EC 1.1.1.41) activity of blowfly mitochondria in the absence of ADP, but in the presence of ADP, AMP caused inhibition. 8. It is suggested that AMP may exert a controlling effect on the oxidative activity of blowfly mitochondria.

摘要

新鲜分离的丽蝇线粒体中，38%的线粒体内腺嘌呤核苷酸以AMP形式存在。2. 与可氧化底物一起孵育时，AMP和ADP浓度下降，ATP浓度上升；丙酮酸与脯氨酸一起孵育时，ATP浓度在6分钟时达到最大值；与磷酸甘油一起孵育时，内源性核苷酸的磷酸化更快。3. 添加解偶联剂羰基氰苯腙导致ATP迅速下降，ADP平行上升，然后ADP转化为AMP。4. 这与大鼠肝脏线粒体的内源性AMP浓度形成对比，大鼠肝脏线粒体的内源性AMP浓度总是低于丽蝇线粒体，并且在不同代谢条件下变化不大。5. 有证据表明，腺苷酸激酶（EC 2.7.4.3）在丽蝇线粒体中有双重分布，一部分位于基质空间，一部分位于线粒体外膜和内膜之间的空间，就像在肝脏和其他线粒体中一样。6. 研究了线粒体基质中AMP浓度变化可能的调节作用。部分纯化的丙酮酸羧化酶（EC 6.4.1.1）和柠檬酸合酶（EC 4.1.3.7）受到2 mM AMP的30%抑制，而丙酮酸脱氢酶（EC 1.2.4.1）不受影响。7. 在没有ADP的情况下，AMP激活丽蝇线粒体的NAD(+)-连接异柠檬酸脱氢酶（EC 1.1.1.41）活性，但在有ADP的情况下，AMP会导致抑制。8. 有人认为，AMP可能对丽蝇线粒体的氧化活性发挥控制作用。