Properties and physiological roles of Na^+-motive respiratory chain in marine bacteria.

海洋细菌Na^-动力呼吸链的特性和生理作用。

基本信息

批准号：
61560110
负责人：
TOKUDA Hajime
金额：
$ 1.02万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560110/
关键词：
Sodium pump Energy-coupling Marine bacteria Respiratory chain キノン還元

项目摘要

The Marine bacterium Vibrio alginolyticus possesses a Na^+ pump that generates an lectrochemical potential of Na^+ as a direct result of respiration. Examinations of Na^+ pump-defective mutants, Napl and Nap2, revealed that Na^+ is extruded at the NADH:quinone oxidoreductase segment of NADH oxidase. In the wild type, two kinds of NADH:quinone oxidoreductases (NQR) are present; one is dependent on Na^+-dependent NQR. The Na^+ and another is not. Both Nap1 and Nap2 lack the activity of Na^+-dependent NQR. The Na^+-dependent NQR of the wild type was purified to near homogeneity and found to be composed of three subunits, <Alpha>, <beta> and <gamma>. Moreover, it was shown that Nap2 has a point mutation in <beta> subunit whereas Napl lacks all the subunits. Mechanism of electron transfer by the Na^+-dependent NQR were examined in detail using purified subunits and NQR complex. The subunit <beta> catalysed the reduction of ubiquinone to ubisemiquinone. The subunit <alpha> and <gamma> were e … More ssential for the reduction of ubiquinone to ubiquinol. NQR complex reconstituted in liposomes generated a membrane potential, which was dependent on Na^+.Besudes V, akgubikttucysm gakiogukuc V, cistucoka aksi retaubs the BA^+-motive NADH oxidase. which requires Na^+ for maximum activity. In order to investigate the distribution of Na^+-motive NADH oxidase in halophiles, Na^+-requiremet of NADH oxidase was exanubed ub narube bacterua. Out of 10 strains examined, 9 strains belonging to Alteromonas, Alcaligenes or Vibrio retained Na^+-dependent NADH oxidases. Moreover,Na^+-dependent site of all NADH oxidases existed at the NADH:quinone oxidoreductase and was inhibited by 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), a specific inhibitor of the Na^+ pump in V. alginolyticus and V. costicola. Na^+-dependent NADH oxidases in all the strajns including V. alginolyticus were able to oxidize deamino-NADH whereas NADH oxidase in Nap1 and Nap2 showed little activity to deamino-NADH. These results indicated that the Na^+-dependent (Na^+-motive) NADH oxidase is a general mechanism to generate energy in marine bacteria and shares some commmon properties. Less

海洋细菌溶藻弧菌拥有Na^+泵，其作为呼吸的直接结果产生Na^+电化学势。对Na^+泵缺陷突变体Napl和Nap2的检查表明，Na^+在Na^+被挤出。 NADH：NADH 氧化酶的醌氧化还原酶片段在野生型中，有两种 NADH：醌氧化还原酶。 (NQR) 存在；一个依赖于 Na^+，另一个则不依赖于 Na^+ 的 NQR。野生型被纯化至接近同质，并发现由三个亚基组成，<α>、<β>和<gamma>。此外，显示Nap2在<β>亚基中具有点突变，而Napl缺乏。使用纯化的亚基和NQR复合物详细检查了Na^+依赖性NQR的电子转移机制。亚基<β>催化泛醌还原为泛半醌。 e ... 更多对于将泛醌还原为泛醇复合物在脂质体中重构所产生的膜电位至关重要。 Na^+。Besudes V、akgubikttucysm gakiogukuc V、cistucoka aksi 修复了需要 Na^+ 才能发挥最大活性的 BA^+ 动力 NADH 氧化酶。为了研究 Na^+ 动力 NADH 氧化酶在嗜盐菌中的分布。 NADH氧化酶的^+-需求被排除在narube细菌之外。检测的10株菌株中，9株属于交替单胞菌属、产碱菌属或弧菌属，保留了Na^+依赖性NADH氧化酶，而且所有NADH氧化酶的Na^+依赖性位点都存在于NADH：醌氧化还原酶上，并被2-庚基-4抑制。 -羟基喹啉-N-氧化物 (HQNO)，溶藻弧菌和溶藻弧菌中 Na^+ 泵的特异性抑制剂。包括溶藻弧菌在内的所有菌株中的 Na^+ 依赖性 NADH 氧化酶都能够氧化脱氨基 NADH，而 Nap1 和 Nap2 中的 NADH 氧化酶对脱氨基 NADH 表现出很少的活性。（Na^+-动机）NADH 氧化酶是海洋细菌中产生能量的通用机制，并具有一些共同的特性。