Molecular Genetic Analysis and Mechanism of Action of Bacterial Cytolysins

本研究旨在积累各种细菌溶细胞素的性质信息，了解它们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的敏感性因动物种属不同而不同，这是由于它们结合VVH的能力不同。一些菌株产生免疫学上不同的VVH。Katoh和Noda研究了金黄色葡萄球菌α毒素和杀白细胞素的细胞溶解作用机制，发现它们的NAD-核糖基化活性对溶解作用很重要。它们还显示了杀白细胞素S-和F-片段的确切作用。樱井发现产气荚膜梭菌α毒素的溶血活性中心和磷脂酶活性中心位于毒素分子的不同位点。此外，他还表明，在毒素对血管平滑肌收缩的作用中，磷脂代谢发生了变化。本田研究了副溶血弧菌耐热直接溶血素（TDH）的结构和功能。他分离出一个产生TDH相关分子的突变体，该突变体不显示溶血活性，并发现突变体溶血素中第90位的甘氨酸残基被天冬酰胺取代。Mizuguchi分离出一株具有编码副溶血性弧菌溶血素（delta-VPH）基因的菌株。Delta-VPH不是通过副溶血性弧菌的常规培养产生的。而delta-VPH制剂对动物模型的攻毒试验表明，该毒素是弧菌的致病因子之一。Nakazawa发现了一种新的头孢假单胞菌溶血素。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.