INHIBITION OF MITOCHONDRIAL AND PARACOCCUS-DENITRIFICANS NADH UBIQUINONE REDUCTASE BY OXACARBOCYANINE DYES - A STRUCTURE-ACTIVITY STUDY
INHIBITION OF MITOCHONDRIAL AND PARACOCCUS-DENITRIFICANS NADH UBIQUINONE REDUCTASE BY OXACARBOCYANINE DYES - A STRUCTURE-ACTIVITY STUDY
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DOI：
10.1016/0006-2952(93)90024-q
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发表时间：
1993-05-25
影响因子：
5.8
通讯作者：
ANDERSON, AC
中科院分区：
文献类型：
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作者：
ANDERSON, WM;WOOD, JM;ANDERSON, AC
在这项研究中，我们确定了3，3‘-二乙氧基碳菁染料(DiOC2(3))、3，3’-二戊氧基碳菁染料(DiOC5(3))和3，3‘-二己基-草酸碳菁染料(DiOC6(3))以及一个草酸碳菁染料3，3’-二乙氧基碳菁染料(DiOC2(4))能抑制牛心脏线粒体NADH氧化酶的活性，其中一种染料DiOC6(3)能抑制副硝化细菌NADH氧化酶的活性。线粒体的I50值为9um(DiOC2(3))，约1um(DiOC5(3)和DiOC6(3))，约3um(DiOC2(4))，而脱氮假单胞菌的I50值约为2um(DiOC6(3))。既不是琥珀酸，也不是细胞色素氧化酶(EC 1.9.3.1)任何一种电子传递链上的化合物都能显著抑制酶的活性，使氧碳菁染料的抑制部位位于NADH和泛醌之间的呼吸链上。在亚线粒体颗粒(SMP)中，四种化合物均能显著抑制依赖NADH的杜苯二酚和辅酶Q1的还原，其中DiOC6(3)的抑制作用最强，对甲苯二酮的还原也有明显的抑制作用。当使用纯化的络合物I时，依赖于NADH的还原被DiOC5(3)抑制，辅酶Q1的还原被所有的草炭菁所抑制。对于脱氮假单胞菌的膜小泡，DiOC6(3)基本上抑制了辅酶Q1的NADH依赖的还原。与络合物I相比，所有的含氧碳菁类化合物都是膜制剂中更有效的抑制剂，说明膜相互作用在抑制中起作用。其抑制机制似乎与鱼藤酮相似，因为(A)基本上只有受鱼藤酮影响的电子受体受到影响，(B)鱼藤酮饱和的SMP可显著减弱对甲苯二酮还原的抑制，(C)对辅酶Q1的抑制可被鱼藤酮不敏感的络合物I和脱氮假单胞菌的膜小泡基本消除。
In this study, we determined that three structurally related oxacarbocyanine dyes, 3,3'-diethyloxacarbocyanine (DiOC2(3)), 3,3'-dipentyloxacarbocyanine (DiOC5(3)), and 3,3'-dihexyl-oxacarbocyanine (DiOC6(3)), and one oxadicarbocyanine, 3,3'-diethyloxadicarbocyanine (DiOC2(4)), inhibit bovine heart mitochondrial NADH oxidase activity and one of them, DiOC6(3), inhibits Paracoccus denitrificans NADH oxidase activity. The mitochondrial I50 values were 9 muM (DiOC2(3)), approximately 1 muM (DiOC5(3)) and DiOC6(3)), and approximately 3 muM (DiOC2(4)), whereas the I50 value for P. denitrificans was approximately 2 muM (DiOC6(3)). Neither succinate nor cytochrome oxidase (EC 1.9.3. 1) activity was inhibited significantly by any of the compounds in either electron transport chain, localizing the inhibitory site of the oxacarbocyanine dyes to the respiratory chain segment between NADH and ubiquinone. With submitochondrial particles (SMP), NADH-dependent reduction of duroquinone and coenzyme Q1 was inhibited markedly by all four compounds with DiOC6(3) being the most potent inhibitor, and the reduction of menadione was inhibited substantially by DiOC6(3). When purified complex I was used, NADH-dependent reduction of ferricyanide was inhibited by DiOC5(3) and coenzyme Q1 reduction was inhibited by all oxacarbocyanines. With P. denitrificans membrane vesicles, DiOC6(3) substantially inhibited NADH-dependent reduction of coenzyme Q1. All the oxacarbocyanines were more effective inhibitors with membrane preparations than with complex I, suggesting that membrane interactions play a role in inhibition. The mechanism of inhibition of the oxacarbocyanines appears to be similar to that of rotenone since (a) essentially only electron acceptors affected by rotenone were affected by the compounds, (b) inhibition of menadione reduction was diminished drastically with rotenone-saturated SMP, and (c) inhibition of coenzyme Q1 was largely eliminated with rotenone-insensitive complex I, and P. denitrificans membrane vesicles.