Structural and functional analysis of Ascaris suum cytochrome b in the nematode methemoglobin reductase system

线虫高铁血红蛋白还原酶系统中猪蛔虫细胞色素b的结构和功能分析

• 批准号: 18590406
• 负责人: TAKAMIYA Shinzaburo
• 金额: $ 2.47万
• 依托单位: Juntendo University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590406/
• 关键词: cytochrome b_5; methemoglobin reductase system; Ascaris suum; X-ray crystallography; adaptation to low-oxygen tension; C. elegans; 蛋白質; X-線構造解析; 結晶化; ヘモグロビン

Objectives : This research project was undertaken to elucidate structural properties of Ascaris suum cytochrome b_5, the component of novel NADH-methemoglobin reductase system , by comparing the coding gene and crystal structure with those of cytochromes b_5 from mammalian host and free-living nematode C. elegans. More specifically, 1) To resolve structural properties of A. suum cytochrome b_5 , which have been gained in the course of parasitic adaptation, 2) To analyze its mode of biosynthesis, i. e. the role of presequence of A. suum cytochrome b_5 by expressing the precursor cytochrome b_5 in C. elegans nematode. Achievements 1) The crystal structure of A. suum cytochrome b_5 was resolved at 1.8 A resolution demonstrating the structure different from that of aerobic mammalian cytochrome b_5(erythrocyte type, soluble). Docking models of A. suum hemoglobin and cytochrome b_5 strongly suggest that they are physiological reaction partners. Immunohistochemical and immunoblotting studies … More showed that A. suum cytochrome b_5 was localized in both the hypodermis and perienteric fluid , and that the cytochrome was a secretary protein. We proposed a working hypothesis that the cytochrome b_5 was a protein specialized during adaptation to low-oxygen tension of host intestinal lumen. To test this hypothesis, cytochrome b_5 species were surveyed from gene data bases of C. elegans, of which genome project has been completed. Four species of C. elegans cytochrome _b5 were found although none of them possesses presequence at all. Hydropathy analysis of the four species suggested that two of them were soluble proteins and one of the two exhibited highest homology with A. suum cytochrome b_5. However, none of the two was detected as expressed sequence tag. 2) Experimental conditions are currently examined because of low efficiency of transfection. 3) Affinity analysis using Biacore, employing Ascaris suum and human cytochromes b_5 as ligand, showed that the latter had less affinity with perienteric hemoglobin than the former. These results supported the working hypothesis described above. Less

目的：本研究项目旨在通过将编码基因和晶体结构与来自哺乳动物宿主和自由生活线虫线虫的细胞色素 b_5 的编码基因和晶体结构进行比较，阐明猪蛔虫细胞色素 b_5（新型 NADH-高铁血红蛋白还原酶系统的组成部分）的结构特性。更具体地说，1) 解析猪 A. suum 细胞色素 b_5 的结构特性，这些特性是在寄生适应过程中获得的，2) 分析其生物合成模式，即。 e.通过在秀丽隐杆线虫中表达前体细胞色素 b_5，A. suum 细胞色素 b_5 前序列的作用。成果 1) 以1.8 A的分辨率解析了A. suum细胞色素b_5的晶体结构，表明其结构不同于需氧哺乳动物细胞色素b_5（红细胞型，可溶性）。猪曲霉血红蛋白和细胞色素b_5的对接模型强烈表明它们是生理反应伙伴。免疫组织化学和免疫印迹研究表明，猪曲霉细胞色素 b_5 定位于皮下组织和肠周液中，并且细胞色素是一种分泌蛋白。我们提出了一个工作假设，即细胞色素 b_5 是一种专门适应宿主肠腔低氧张力的蛋白质。为了验证这一假设，我们从已经完成基因组计划的线虫基因数据库中调查了细胞色素b_5物种。发现了四种线虫细胞色素_b5，尽管它们都不具有前序。对这四个物种的水疗分析表明，其中两个是可溶性蛋白质，并且两个中的一个与猪曲霉细胞色素b_5表现出最高的同源性。然而，两者均未检测到表达序列标签。 2)由于转染效率低，目前正在检查实验条件。 3)使用Biacore进行亲和力分析，以猪蛔虫和人细胞色素b_5为配体，表明后者与肠周血红蛋白的亲和力低于前者。这些结果支持了上述工作假设。较少的

项目成果

Unique structure of Ascaris suum b_5-type cytochrome : an additional a-helix and positively charged residues on the surface domain interact with redox partners

猪蛔虫 b_5 型细胞色素的独特结构：额外的 a 螺旋和表面结构域上的带正电残基与氧化还原伙伴相互作用

• 发表时间: 2006
• 期刊: Biochemical Journal 394(2)
• 作者: Yokota;T.;Nakajima;Y.;Yamakura;F.;Sugio;S.;Hashimoto;M.;Takamiya S
• 通讯作者: Takamiya S

Ascaris suum cytochrome b_5,an adult-specific secretory protein reducing oxygen-avid ferric hemoglobin

猪蛔虫细胞色素 b_5，一种成人特异性分泌蛋白，可还原亲氧铁血红蛋白

• 发表时间: 2008
• 期刊: Archives of Biochemistry and Biophysics 471
• 作者: Daisuke;Kimura;Muneaki Hashimoto
• 通讯作者: Muneaki Hashimoto

Crystal structure and function of cytochrome b_5 from parasitic nematode Ascaris suum

寄生性猪蛔虫细胞色素b_5的晶体结构和功能

• 发表时间: 2006
• 作者: Shinzaburo;Takamiya;Shinzaburo Takamiya;Shinzaburo Takamiya
• 通讯作者: Shinzaburo Takamiya

Unique structure of Ascaris suum b_5-type cytochrome:an additional α-helix and positively charged residues on the surface domain interact with redox partners

猪蛔虫b_5型细胞色素的独特结构：表面域上额外的α螺旋和带正电荷的残基与氧化还原伙伴相互作用

• 发表时间: 2006
• 期刊: Biochemical Journal 394
• 作者: Kobayashi;T.;Sato;S.;Takamiya;S.;Komaki-Yasuda;K.;Yano;K.;Hirata;A.;Onitsuka;I.;Hata;M.;Mi-ichi;F.;Tanaka;T.;Hase;T.;Miyajima;A.;Kawazu;S.;Watanabe;Y.;Kita;K;Tamaki Kobayashi;Takehiro Yokota
• 通讯作者: Takehiro Yokota

Crystal structure of Ascsris cytochrome bs : Specific adaptation to the nematode myoglobin

Ascsris 细胞色素 bs 的晶体结构：对线虫肌红蛋白的特异性适应

• 发表时间: 2006
• 期刊: 11th International Congress of Parasitology ICOPAXI, MEDIMOND, International Proceedings
• 作者: Yokota;T.;Nakajima;Y.;Yamakura;F.;Sugio;S.;Hashimoto;M.;Takamiya S;Takehiro Yokota;Shinzaburo Takamiya
• 通讯作者: Shinzaburo Takamiya