Singh A P, Bragg P D
Can J Biochem. 1979 Dec;57(12):1384-91. doi: 10.1139/o79-184.
Respiration- and ATP-dependent transhydrogenation of NADP+ by NADH in everted membrane vesicles from Escherichia coli is inhibited by nigericin but is relatively insensitive to valinomycin. The sensitivity to nigericin is enhanced 30-fold in the presence of valinomycin. It is concluded that both the transmembrane pH difference and the membrane potential constitute the driving force for energy-dependent transhydrogenation. Respiration- and ATP-dependent transhydrogenation are inhibited by tributyltin chloride. Although effects on the energization system have not been excluded, the inhibitor appears to react with a sulfhydryl group on the transhydrogenase enzyme. This inhibition is not dependent on the presence of a permeant anion and can be reversed by mono- and particularly di-thiol compounds. The transhydrogenase is also inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), N-ethylmaleimide, p-chloromercuriphenyl sulfonic acid, and Zn2+, but these reagents are less effective than tributyltin chloride. Energy-independent transhydrogenation is inhibited at high concentrations (20 mM) of cysteine. The reason for this is unknown.
在大肠杆菌外翻膜囊泡中，NADH对NADP⁺的呼吸及ATP依赖性转氢作用受到尼日利亚菌素的抑制，但对缬氨霉素相对不敏感。在存在缬氨霉素的情况下，对尼日利亚菌素的敏感性增强30倍。得出的结论是，跨膜pH差和膜电位均构成能量依赖性转氢作用的驱动力。呼吸及ATP依赖性转氢作用受到氯化三丁基锡的抑制。尽管未排除对能量化系统的影响，但该抑制剂似乎与转氢酶上的一个巯基发生反应。这种抑制不依赖于渗透性阴离子的存在，并且可以被单硫醇化合物尤其是二硫醇化合物逆转。转氢酶也受到5,5'-二硫代双(2-硝基苯甲酸)、N-乙基马来酰亚胺、对氯汞苯磺酸和Zn²⁺的抑制，但这些试剂的效果不如氯化三丁基锡。在高浓度（20 mM）的半胱氨酸下，非能量依赖性转氢作用受到抑制。其原因尚不清楚。
