Characterization of denitrifying enzymes in photosynthetic bacterium

光合细菌反硝化酶的表征

• 批准号: 11460036
• 负责人: OKUBO Akira
• 金额: $ 9.54万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11460036/
• 关键词: denitrification; multi-cupper enzyme; Rhodobacter sphaeroides f.sp. denitrificans; nitrous oxide; 脱窒; N_2O; 金属酵素; 光合成細菌

Rhodobacter sphaeroides f. sp. denitrificans IL 106 is the first isolated strain as a photosynthetic denitrifying bacteria, which can grow depending on a variety of energy-generating systems, i.e., not only denitrification, but also O_2 respirarion, dimethyl sulfoxide respiration and photosynthesis.Denitrifying enzymes in this photosynthetic bacterium,were studied. Nitrous oxide reductase (N_2OR), nitrite reductase (NIR) and nitric oxide reductase (NOR) were examined. Especially, N_2OR was intensively studied and characterized.The N_2OR from this strain was purified by ammonium sulfate fractionation, gel filtration chromatography and anion exchange chromatography. This purified enzyme is composed of two identical subunits and contains four copper atoms per subunit. The subunit molecular mass was 66 kDa determined by MALDI-TOF-MS. By means of ESR measurement, this enzyme contains at least three types of copper centers, namely, CU_A, Cuz_1 and Cuz_3. The CU_A center, which is different from Cu(type 1) or Cu(type 2) and found only in N_2OR and cytochrome oxidase, was found in this enzyme and supposed to play a role in electron transfer.

球形红杆菌(Rhodbacter sphaeroides f.)反硝化细菌IL-106是我国首次分离到的一株光合作用反硝化细菌，该菌不仅可以进行反硝化作用，还可以进行氧气呼吸、二甲基亚砜呼吸和光合作用等多种能量产生系统的生长。测定一氧化二氮还原酶(N2OR)、亚硝酸盐还原酶(NIR)和一氧化氮还原酶(NOR)。对该菌株的N_2OR进行了深入的研究和鉴定，并通过硫酸铵分级沉淀、凝胶过滤层析和阴离子交换层析对其进行了分离纯化。这种纯化的酶由两个相同的亚基组成，每个亚基含有四个铜原子。用MALDI-TOF-MS测定亚基相对分子质量为66 kDa。经ESR测定，该酶至少含有三种类型的铜中心，即CuA、CuZ_1和CuZ_3。在该酶中发现了一种不同于铜(类型1)或铜(类型2)的铜中心，它只存在于N_2OR和细胞色素氧化酶中，可能在电子转移中起作用。

项目成果

K.Sato et al.: "Characterization of Multi-Copper Enzymes Nitrous Oxide Reductase from Rhodobacter sphaeroides f.sp. denitrificans"Journal of Biochemistry. 124・1. 51-54 (1998)

K. Sato 等人：“来自球形红细菌反硝化菌的多铜酶一氧化二氮还原酶的特性”，生物化学杂志 124・1（1998 年）。

K.Sato et al.: "Anaerobic Purification and Characterization of Nitrous Oxide Reductase from Rhodobacter sphaeroides f.sp. denitrificans IL106"Journal of Biochemistry. 125・5. 864-868 (1999)

K. Sato 等人：“球形红细菌反硝化菌 IL106 中一氧化二氮还原酶的厌氧纯化和表征”《生物化学杂志》125・5（1999 年）。

Kiichi Sato, Akira Okubo, Sunao Yamazaki: "Characterization of Multi-Copper Enzymes Nitrous Oxide Reductase from Rhodobacter sphaeroides f.sp. denitrificans."Journal of Biochemistry. 124,1. 51-54 (1998)

Kiichi Sato、Akira Okubo、Sunao Yamazaki：“来自球形红细菌 f.sp. 脱氮菌的多铜酶一氧化二氮还原酶的表征。”生物化学杂志。

Kiichi Sato, Akira Okubo, Sunao Yamazaki: "Anaerobic Purification and Characterization of Nitrous Oxide Reductase from Rhodobacter sphaeroides f.sp. denitrificans IL106"Journal of Biochemistry. 125,5. 864-868 (1999)

Kiichi Sato、Akira Okubo、Sunao Yamazaki：“球形红杆菌反硝化菌 IL106 中一氧化二氮还原酶的厌氧纯化和表征”生物化学杂志。