Analysis of Maturation pathway protein toxin of Enteric Bacteria and Studies of Prevention of Diarrhea

肠道细菌成熟途径蛋白毒素分析及预防腹泻的研究

• 批准号: 18590423
• 负责人: OKAMOTO Keinosuke
• 金额: $ 2.49万
• 依托单位: Okayama 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-18590423/
• 关键词: Enteric infection; Bacterial toxin; Maturation pathway; Enterotoxin; Protease; Hemolvsin; Escherichia coli; Aeromonas; セリンプロテアーゼ; メタロプロテアーゼ; カルボキシ末端

The studies on maturation pathway of enterotoxin and protease of Aeromonas and heat-stable enterotoxin of enterotoxigenic Escherichia coil were performed in this study. The diarrheagenic toxin of Aeromonas has rapacity to lyse erythrocytes, therefore, another name the toxin is hemolysin. The culture filtrates of A. sobria and A. hydrophila exhibit hemolytic activity, because the hemolysin is produced into the solution. However, the filtrate of A. caviae does not exhibit However, A. caviae caused diarrhea in humans. We examined the production of diarrheagenic toxin of A. caviae. It has been shown that A. caviae synthesis the hemolysin and release it into outside of the cells, however, the hemolysin is broken by the proteases produced by A. caviae. Therefore, the culture filtrate of A. caviae does not exhibit hemolytic activity. In intestinal lumen and agar medium, these hemolysins produced by A. caviae can bind the appropriate cells and express the activity before these hemolysins are broken by proteases. Another finding of this research project is that production of serineprotease and metallo protease of A. sobria is inhibited by salt (sodium chloride) in the medium. hi the medium containing sodium chloride at the ratio of more than 2%, the production of these proteases is significantly repressed. The studies on the mechanism of the repression showed that the repressions of production of serineprotease and metallo pro ease are derived from inhibitions of maturation pathway and of transcriptional stage of each toxin, respectively. In the study about Escherichia coil, the structure of TolC which is involved in the translocation of ST(heat-stable enterotoxin) across the outer membrane was examined. To examined, we constructed the chimeric TolC which is consisted of E. coli TolC and Vibrio parahaemolyticus TolC. The result shows that the region covering 198th -214th of E. coli TolC plays an important role in the transport of ST.

本研究对气单胞菌的肠毒素和蛋白酶的成熟途径以及产肠毒素埃希氏菌的热稳定型肠毒素进行了研究。气单胞菌的致泻毒素具有溶解红细胞的能力，故又称溶血素。嗜水假单胞菌和嗜水假单胞菌的培养滤液表现出溶血活性，因为溶血素在溶液中产生。然而，鼠腹曲霉滤液不表现出鼠腹曲霉引起人腹泻。我们研究了豚鼠弓形虫致泻毒素的产生。研究表明，豚鼠a.a caviae合成溶血素并将其释放到细胞外，但溶血素被豚鼠a.a caviae产生的蛋白酶破坏。因此，黄颡鱼培养滤液不具有溶血活性。在肠腔和琼脂培养基中，在溶血素被蛋白酶破坏之前，这些溶血素可以结合合适的细胞并表达活性。本研究项目的另一个发现是，培养基中的盐（氯化钠）抑制了索布酵母丝氨酸蛋白酶和金属蛋白酶的产生。在氯化钠含量大于2%的培养基中，这些蛋白酶的产生明显受到抑制。对其抑制机制的研究表明，丝氨酸蛋白酶和金属蛋白酶的抑制分别来源于对成熟途径和转录阶段的抑制。在对大肠杆菌线圈的研究中，研究了参与热稳定型肠毒素（ST）跨外膜转运的TolC的结构。为此，我们构建了由大肠杆菌TolC和副溶血性弧菌TolC组成的嵌合TolC。结果表明，大肠杆菌TolC的第198 ~ 214段在ST的转运中起重要作用。

项目成果

Crystal structure of Aeromonas sobria serine protease, prototype Kexin/Furin protease: The extra occluding domain regulates protein substrate specificity

温和气单胞菌丝氨酸蛋白酶的晶体结构，原型Kexin/Furin蛋白酶：额外的封闭结构域调节蛋白质底物特异性

• 发表时间: 2007
• 作者: 小野 久弥;ほか;Hideaki Tsuge
• 通讯作者: Hideaki Tsuge

アエロモナスの菌体外毒素産生と環境

气单胞菌外毒素产生与环境

• 发表时间: 2006
• 作者: 李 仲娟;ほか;岡本敬の介
• 通讯作者: 岡本敬の介

スルホンアミド基を有する抗菌剤

具有磺酰胺基团的抗菌剂

• 发表时间: 2007

Fluid Secretion caused by Aerolysin-like Hemolysin of Aeromonas sobria in the Intestines Is Due to Stimulation of Production of Prostaglandin E2 via Cyclooxygenase-2 by the Intestinal Cells

肠道内气单胞菌类气溶素溶血素引起的液体分泌是由于肠细胞通过环加氧酶 2 刺激产生前列腺素 E2

• 发表时间: 2008
• 期刊: Infection and Immunity 76
• 作者: Maruo;S.;丸尾 聖爾;Seiji Maruo;丸尾 聖爾;Seiji Maruo;Seiji Maruo;Seiji Maruo;Yoshio Fujii
• 通讯作者: Yoshio Fujii

Influence of salt surroundings on the production of proteases into milieu

盐环境对环境中蛋白酶产生的影响

• 发表时间: 2007
• 作者: Eizo;Takahashi;Eizo Takahashi
• 通讯作者: Eizo Takahashi