Molecular Genetic Analysis and Mechanism of Action of Bacterial Cytolysins

本研究项目旨在积累各种细菌溶细胞酶的性质信息，了解其在感染中的确切作用。Shinoda纯化了创伤弧菌溶血素（VVH）并对其性质进行了研究。红细胞对VVH的敏感性因动物种类的不同而不同，因为它们结合VVH的能力不同。一些菌株产生免疫上不同的VVH。Katoh和Noda研究了金黄色葡萄球菌α -毒素和白细胞素的溶细胞作用机制，发现它们的nadr -核糖基化活性对溶细胞作用很重要。他们还发现了杀白细胞素S和f片段的确切作用。Sakurai发现，产气荚膜梭菌α -毒素的溶血活性和磷脂酶活性中心位于毒素分子的不同位置。此外，他还发现毒素对血管平滑肌收缩的作用改变了磷脂代谢。Honda研究了副溶血性弧菌耐热直接溶血素（TDH）的结构和功能。他分离出一个突变体，产生一个不显示溶血活性的tdh相关分子，并发现该突变体溶血素中90位的甘氨酸残基被天冬酰胺取代。Mizuguchi从副溶血性弧菌中分离出一个溶血素（delta-VPH）基因的转化体。通常的副溶血性弧菌培养不能产生Delta-VPH。然而，delta-VPH制剂对动物模型的挑战表明该毒素是弧菌的致病因素之一。Nakazawa发现了一种新的cepatia假单胞菌溶血素，该溶血素是非蛋白质的，具有抗真菌活性。这些结果为进一步了解细菌溶细胞素的作用机制提供了重要的信息。

This research projiects was organized to accumulate the information of property of various bacterial cytolysisns and to understand their exact role in infection. Shinoda purified Vibrio vulnificus hemolysin (VVH) and studied its property. Sensitivity of erythrocytes to VVH varied with the animal species because of difference of their ability to bind VVH. Some strains produced immunologically different VVH. Katoh and Noda studied the mechanism of cytolytic action of alpha-toxin and leukocidin of Staphylococcus aureus and found that their NAD-ribosylation activity was important to the lytic action. They also showed the exact role of S- and F-fragment of leukocidin. Sakurai found that active center for hemolytic activity and phospholipase of alpha-toxin of Clostridium perfrigens located on different sites of the toxin molecule. Furthermore, he showed change of phospholipid metabolism in action of the toxin on contraction of blood vessel smooth muscle. Honda studied structure and function of V. parahaemolyticus thermostable direct hemolysin (TDH). He isolated a mutant producing a TDH-related molecule which did non show hemolytic actibity and found that glycine residue at 90th was replaced with asparagine in the mutant hemolysin. Mizuguchi isolated a transformant which had gene encoding a hemolysin (delta-VPH) of V. parahaemolyticus. Delta-VPH was not produced by usual cultivation of V. parahaemolyticus. However, challenge of delta-VPH preparation to animal model suggested that the toxin was one of the pathogenic factor of the vibrio. Nakazawa found a new hemolysin of Pseudomonas cepatia The hemolysin was noon-proteinic and showed antimycotic activity. These results presented the important information for general understanding of the mechanism of action of bacterial cytolysins.