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。

• 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

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（Vibrio alginolyticus）具有一个Na^+泵，它通过呼吸作用直接产生Na^+的电化学势。对Na^+泵缺陷突变体Nap 1和Nap 2的检测显示，Na^+在NADH氧化酶的NADH：醌氧化还原酶区段被挤出。在野生型中，存在两种NADH：醌氧化还原酶（NQR）;一种依赖于Na^+依赖的NQR。Na^+和另一个不是。Nap 1和Nap 2都缺乏Na^+依赖的NQR活性。野生型的Na^+依赖性NQR被纯化至接近同质，并发现由三个亚基、<Alpha>、<beta>和组成<gamma>。此外，还显示Nap 2在亚基中具有点突变<beta>，而Napl缺乏所有亚基。利用纯化的亚基和NQR复合物详细研究了Na^+依赖的NQR的电子传递机制。该亚基<beta>催化泛醌还原为泛半醌。亚基<alpha>和<gamma>为E ...更多信息 对于将泛醌还原为泛醇是必要的。脂质体中重组的NQR复合物产生依赖于Na^+的膜电位。Besudes V，akgubikttucysm gakiogukuc V，cistucoka aksi retubs BA^+-motive NADH氧化酶。它需要Na^+才能发挥最大的活性。为了研究Na^+-动力型NADH氧化酶在嗜盐菌中的分布，对盐菌narube natiua的Na^+-需要量进行了研究。在10个菌株中，有9个属于交替单胞菌属、产碱菌属或弧菌属的菌株保留了Na^+依赖型NADH氧化酶。此外，所有NADH氧化酶的Na^+依赖位点都存在于NADH：醌氧化还原酶上，并被2-庚基-4-羟基喹啉-N-氧化物（HQNO）抑制，HQNO是溶藻弧菌和肋状弧菌中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^+依赖型NADH氧化酶都能氧化脱氨基-NADH，而Nap 1和Nap 2中的NADH氧化酶对脱氨基-NADH几乎没有活性。这些结果表明，Na^+依赖型（Na^+动力型）NADH氧化酶是海洋细菌产生能量的一种普遍机制，并具有一些共同的性质。少

项目成果

Tokuda,Hajime: FIBS Lett.215. 335-338 (1987)

德田肇：FIBS Lett.215。

徳田元: 日本農芸化学会誌. 61. 1-9 (1987)

Hajime Tokuda：日本农业化学学会杂志 61. 1-9 (1987)。

Tokuda, Hajime: "Conjugation-dependent recovery of the Na^+ pump in a mutant of Vibrio alginolyticus lacking three subunits of the Na^+ pump." FEBS Lett.215. 335-338 (1987)

Tokuda, Hajime：“在缺乏 Na^ 泵三个亚基的溶藻弧菌突变体中，Na^ 泵的结合依赖性恢复。”

Tokuda, Hajime: "Roles of the respiratory Na^+ pump in bioenergetics of Vibrio alginolyticus." J. Biochemistry. 103. (1988)

Tokuda, Hajime：“呼吸钠泵在溶藻弧菌生物能学中的作用。”