重组海参溶菌酶理化特性及生物活性的初步研究

Physicochemical properties and biological activity of recombinant lysozyme from Stichopus japonicus

将构建好的重组海参溶菌酶毕赤酵母菌株进行诱导表达，用CM52-纤维素阳离子交换柱分离得到电泳纯的重组海参溶菌酶。利用浊度法测定该酶的活性，滤纸片液体扩散法测定其抑菌谱。结果显示，重组海参溶菌酶的最适pH值为6．5，最适温度为35℃，在pH5．0～7．5、50qC以下有较好的稳定性。抑菌谱测定结果显示重组海参溶菌酶对6种指示菌均表现出抑菌性，尤其对副溶血弧菌的抑制作用最强。上述结果均与天然海参溶菌酶一致。

Physicochemical properties and biological activity of recombinant Stichopus japonicus lysozyme were studied in this paper. Firstly, the constructed Pichia pastoris was induced to express recombinant Stichopus japonicus lysozyme by methanol, and the electrophoretic pure lysozyme was obtained by CM52-cellulose cation exchange column. Secondly, at different pH and temperature, the activity of recombinant Stichopus japonicus lysozyme was detected by turbidity measurement in order to determine the optimum pH, optimum temperature, pH stability and thermal stability. Thirdly, the antimicrobial spectrum of recombinant Stichopusjaponicus lysozyme was determined by the liquid diffusion method. The results showed that the optimum pH was 6.5, and the optimum temperature was 35℃, at pH 5.0-7.5. Under 50 %, the recombinant Stichopusjaponicus lysozyme exhibits relative higher stability. The results of antimicrobial spectrum indicated that the recombinant Stichopus japonicus lysozyme showed their antimicrobial activity toward 6 kinds of indicator bacteria, and especially to Vibrio parahaemolyticus. These results were consistent with the result of natural Stichopus japonicus lysozyme.