Kim Y J, Song K B, Rhee S K
Department of Microbiology, Changwon National University, Kyungnam, Republic of Korea.
J Bacteriol. 1995 Sep;177(17):5176-8. doi: 10.1128/jb.177.17.5176-5178.1995.
Membrane vesicles prepared from Zymomonas mobilis oxidized NADH exclusively, whereas deamino-NADH was little oxidized. In addition, the respiratory chain-linked NADH oxidase system exhibited only a single apparent Km value of approximately 66 microM for NADH. The NADH oxidase was highly sensitive to the respiratory chain inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide. However, the NADH:quinone oxidoreductase was not sensitive to 2-heptyl-4-hydroxyquinoline-N-oxide and was highly resistant to another respiratory chain inhibitor, rotenone. Electron transfer from NADH to oxygen generated a proton electrochemical gradient (inside positive) in inside-out membrane vesicles. In contrast, electron transfer from NADH to ubiquinone-1 generated no electrochemical gradient. These findings indicate that Z. mobilis possesses only NADH:quinone oxidoreductase lacking the energy coupling site.
运动发酵单胞菌制备的膜囊泡仅氧化NADH，而脱氨基NADH几乎不被氧化。此外，呼吸链连接的NADH氧化酶系统对NADH仅表现出一个约66微摩尔的表观Km值。NADH氧化酶对呼吸链抑制剂2-庚基-4-羟基喹啉-N-氧化物高度敏感。然而，NADH：醌氧化还原酶对2-庚基-4-羟基喹啉-N-氧化物不敏感，并且对另一种呼吸链抑制剂鱼藤酮具有高度抗性。从NADH到氧气的电子传递在内翻膜囊泡中产生质子电化学梯度（内侧为正）。相反，从NADH到泛醌-1的电子传递不产生电化学梯度。这些发现表明运动发酵单胞菌仅拥有缺乏能量偶联位点的NADH：醌氧化还原酶。
