磷脂酶A1(Lecitase Ultra)催化水解油脂机理研究(Ⅰ)——磷脂酶A1(Lecitase Ultra)组成及酶学特性

摘要

采用凝胶色谱、凝胶电泳和生物质谱分析了磷脂酶A1(Lecitase Ultra)(PLA1)的主要组成,结果表明PLA1主要由4种同工酶组成,这4种同工酶在氨基酸序列上与棉状嗜热丝孢菌(Thermomyces lanuginosus)的脂肪酶高度吻合.测得PLA1水解大豆油的最适pH为6.8,最适温度为40℃.PLA1在pH 4～8之间,温度低于45℃下具有良好的稳定性,在pH 3以下和pH 10以上不稳定.%The composition of phospholipase A1(Lecitase Ultra)(PLA1) was analyzed by gel chromatography,gel electrophoresis and bio-mass spectrometry.The result showed that PLA1 was composed of 4 isoenzymes whose amino acid sequences were very similar to that of Thermomyces lanuginosus lipase.The optimal pH value and temperature for hydrolysis of soybean oil by PLA1 was 6.8 and 40℃,respectively.PLA1 showed a good stability at pH value range of 4 to 8 and temperature below 45℃.However,PLA1 became unstable when the pH value was below 3 or over 10.