PROPERTIES OF PROTEOLYTIC TOXIN OF VIBRIO ANGUILLARUM FROM DISEASED FLOUNDER

• Published in: Chinese journal of oceanology and limnology Vol. 20; no. 4; pp. 316 - 322
• Main Author: 莫照兰 陈师勇 张培军
• Format: Journal Article
• Language: English
• Published: Experimental Biolology Laboratory, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China 2002
• Subjects: Marine; 弧菌毒素; 比目鱼; 淀粉酶; 淋巴细胞; 溶血毒性; 白明胶酶; 组织病理学; 细胞外产物; 蛋白酶; toxicity; Vibrio anguillarum; extracellular products; p rotease
• ISSN: 0254-4059; 1993-5005

Extracellular products(ECP)produced by Vibrio anguillarum strain M3 originally isolated from diseased flounder(Paralichthys olivaceus)were prepared.ECP of M3 showed gelatinase,casinase,amylase and haemolytic activity on agarose plates.High protease activity against azocasin was detected.Bacterium M3 showed highest growth and protease activity at 25℃。The Protease present in ECP showed maximal activity at pH 8 and 55℃；was completely inactivated by application of 80℃ heat for 30 min;was completely inhibited by EDTA and HgCl2,and was partially inhibited by PMSF,SDS,MnCl2 and iodoacetic acid;but not inhibited by CaCl2 and MgCl2.The ECP was toxic to flounder fish at LD50 values of 3.1 μg protein/g body weight.The addition of HgCl2 and application of heat at 50℃ decreased the lethal toxicity of ECP.When heated at 100℃,ECP lethality to flounder was completely in-hibited.After intramuscular injection of ECP into flounder,it showed evident histopathological changes including necrosis of muscle,extensive deposition of haemosiderin in the spleen,dilated bolld vessels congested with numerous lymphocytes in the liver.These results showed that ECP protease was a lethal factor produced by the baterium V.anguillarum M3.