サケ科魚類せっそう病原因菌Ａｅｒｏｍｏｎａｓ ｓａｌｍｏｎｉｃｉｄａの産生する病因物質について ＩＩＩ Ａｅｒｏｍｏｎａｓ ｓａｌｍｏｎｉｃｉｄａ Ａｒ‐４ （ＥＦＬＤ）の産生するプロテアーゼの特性 Enzymatic properties of the purified extracellular protease of <i>Aeromonas salmonicida</i>, Ar-4 (EFDL)
In a previous paper, we examined the toxicity of the extracellular protease of <i>A. salmonicida</i>, Ar-4 (EFDL) on yamabe (<i>Oncorhynchus masou f. ishikawai</i>) and goldfish (<i>Carassius auratus</i>). From these results, we considered the protease secreted by this bacterium was a causative agent of furunculosis.<br> In this paper, we observed enzymatic properties of the purified protease. The results obtained were summarized as follows:<br> 1. The molecular weight of purified protease was estimated to be 71, 000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis.<br> 2. The purified protease showed maximal activity at pH 9.4 and 50°C. It was stable over the pH range 5.0 to 10.0 and was completely inactivated by temperature at 56°C.<br> 3. The protease was presumably classified an alkaline serine protease and it showed chymotryptic properties since it was significantly inhibited by diisopropylfluorophosphate (DFP) and tosyl-phenylalanine-chloromethyl ketone (TPCK) and hydrolyzed <i>N</i>-benzoyl-L-tyrosine ethyl ester (BTEE).
日本水産学会誌 50(1), 145-150, 1984