Biochemical analysis of the enzymatic complex responsible for the generation of superoxide anion on the cell surface of Chattonella marina

查顿内拉marina（C. marina）是一种针形藻类鞭毛虫，是最具毒性的赤潮浮游植物之一，对鱼类，特别是黄尾五鳍鱼（Seriola quinquer adiata）具有很高的毒性。我们以前的研究已经证明，动脉血氧分压的降低是鱼在暴露于C后观察到的最早的生理紊乱。码头鱼类暴露于C.马里纳还指出，过多的粘液会阻碍呼吸水流通过鳃板，从而干扰氧气的输送，导致窒息。海洋梭菌的生化特性之一是产生活性氧（ROS），如超氧阴离子和过氧化氢。在这项研究中，我们分析了酶复合物。ROS的产生可能与C.码头我们的研究结果表明，糖萼可能包括活性氧产生酶系统。糖萼是一种由碳水化合物和蛋白质组成的复杂结构，很容易从C. marin细胞对各种物理刺激做出反应。事实上，我们使用抗糖萼抗血清的免疫组织化学分析显示，在C.码头暴露。此外，我们还发现从C. marina细胞悬浮液在NADPH存在下产生ROS。这些结果表明，糖萼可能在C.码头我们最近的研究表明，C. marina含有光敏溶血毒素作为一种新的毒性因子。该毒素在C.码头

Chattonella. marina (C. marina), a raphidophycean flagellate, is one of the most noxious, red tide phytoplankton, and is highly toxic to fish, especially to yellowtail Seriola quinquer adiata. Previous our studies have demonstrated that a decrease in.oxygen partial pressure of arterial blood is the earliest physiological disturbance observed in fish after exposure to C. marina. Physiological and histological studies of fish exposed to C. marina also suggested that the blockade of respiratory water flow through the gill lamellae caused by excessive mucus interferes with oxygen transfer, resulting in asphyxia. One of the biochemical feature of C, marina is the ability to generate reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide. In this study, we analyzed the enzymatic complex. responsible for the production of ROS, which may be located on the cell-surface of C. marina. Our results suggest that glycocalyx may include ROS generating enzymatic system. Glycocalyx is a complex structure consisted of carbohydrates and proteins, and is easily discharged from C. marin cells in responding to various physical stimuli. In fact, our immunohistochemical analysis using anti-serum against glycocalyx revealed that significant amounts of glycocalyx were attached on the gill surface of yellowtail after C. marina exposure. Furthermore, we found that crude glycocalyx prepared from C. marina cell suspension produces ROS in the presence of NADPH. These findings suggest that glycocalyx may play a important role in the ROS-mediated fish-killing mechanism of C. marina. In addit ion to ROS, our recent study suggest that C. marina contains photoactive hemolytic toxin as a novel toxic factor. Further studies are required to clarify the involvement of such he molytic toxin in the fish-killing mechanism of C. marina.