柞蚕溶菌酶基因在酵母中的表达及对变形链球菌的作用

Expression of a lysozyme from antheraea pernyi in pastoris and the effects of recombinant Ap-lysozyme on Streptococcus mutans

目的:建立柞蚕溶菌酶的毕赤酵母表达系统,分析重组的柞蚕溶菌酶对变形链球菌的作用。方法:毕赤酵母表达系统用于柞蚕溶菌酶的表达及纯化。琼脂扩散法用于检测重组柞蚕溶菌酶对变形链球菌的抗菌活性。结果:在毕赤酵母表达系统中表达的柞蚕溶菌酶能够分泌到胞外,并且被糖基化。抑菌圈结果显示重组柞蚕溶菌酶对变形链球菌有抑菌活性。柞蚕溶菌酶在酵母菌中的表达是在5ml/L甲醇诱导下96h达到高峰;纯化的重组柞蚕溶菌酶相对分子质量约为20000。结论:重组的柞蚕溶菌酶具有抑制变形链球菌生长的作用。

Objective： To construct the antheraea peruyi lysozyme（ApLZ） expression system using the methylotrophic yeast Pichia pastoris, to assay the antibacterial activity of the recombinant ApLZ against Streptococcus mutans. Methods：The ApLZ expression system was used in the expression and purity of Ap-lysozyme. The antibacterial activity of the recombinant ApLZ against Streptococcus mutans were assayed by using agar diffusion method. Resuits：Expression system of ApLZ was constructed using the methylotrophic yeast Pichia pastoris as a host. ApLZ was expressed correctly and secreted efficiently when the native signal sequence of ApLZ was used as secretion signal. The level of ApLZ expression in Pichia pastoris peaks at 96 h after the induction of sustaining 5 ml/L methanol. The molecular weight of the recombinant ApLZ is about 20 000. Conclusion：The recombinant ApLZ is active in inhibiting the growth of Streptococcus mutaus.