Bisschop A, de Jong L, Lima Costa M E, Konings W N
J Bacteriol. 1975 Mar;121(3):807-13. doi: 10.1128/jb.121.3.807-813.1975.
The rate of reduced nicotinamide adenine dinucleotide (NADH) oxidation by membrane vesicles from Bacillus subtilis W23 increases three- to fourfold during logarithmic growth, reaching maximal levels in early stationary phase. Initial rates of L-proline, L-alanine, and L-glutamate transport energized by NADH closely parallel the increase in NADH oxidation. In vesicles prepared at different stages of growth, a constant number of NADH molecules varying from 150 to 260 have to be oxidized to transport one molecule of amino acid. Membrane vesicles from B. subtilis aroD (strain RB163), a mutant defective in menaquinone synthesis, do not transport amino acids in the presence of NADH. Ascorbate plus phenazine methosulfate, however, energizes amino acid transport equally well as in vesicles of B. subtilis W23. NADH oxidation and NADH-driven amino acid transport can be restored instantaneously by the addition of menadione (vitamin K3).
来自枯草芽孢杆菌W23的膜囊泡对还原型烟酰胺腺嘌呤二核苷酸(NADH)的氧化速率在对数生长期增加三到四倍,在稳定期早期达到最高水平。由NADH供能的L-脯氨酸、L-丙氨酸和L-谷氨酸的初始转运速率与NADH氧化的增加密切平行。在不同生长阶段制备的囊泡中,为转运一分子氨基酸,必须氧化150至260个数量恒定的NADH分子。来自枯草芽孢杆菌aroD(RB163菌株)的膜囊泡,一种在甲萘醌合成中存在缺陷的突变体,在NADH存在的情况下不转运氨基酸。然而,抗坏血酸加吩嗪硫酸甲酯与枯草芽孢杆菌W23的囊泡一样能很好地为氨基酸转运供能。通过添加甲萘醌(维生素K3),NADH氧化和NADH驱动的氨基酸转运可以立即恢复。