毕赤酵母表达罗氏耶尔森氏菌（Yersinia rohdei）植酸酶和酶学特性研究

摘要

按毕赤酵母偏爱密码子，将来自Yersinia rohdei的植酸酶基因（YrAPPA）进行了化学合成，并成功在毕赤酵母GS-115中异源分泌表达，重组植酸酶分泌量能达到72μg/mL。酶学特性研究结果表明：酶比活达到1500 U/mg，重组植酸酶的最适反应温度和 pH分别为55℃和4.5；纯化的重组植酸酶能耐受60℃高温，且pH 3—7.5范围内重组植酸酶有良好的稳定性；Cu2＋、Zn2＋、Fe3＋对植酸酶活性有抑制作用；重组植酸酶有抗胃蛋白酶和胰蛋白酶水解特性。%Yersinia rohdei phytase gene (YrAPPA)was chemically synthesized according to the codon usage of Pichia pastoris and successfully expressed in P.pastoris GS-1 1 5 ,with the secretion yield of recombinant phytase being up to about 72 μg/mL.The enzymatic characterization showed that the specific activity of enzyme is 1 500 U/mg,and the optimal reacting temperature and pH of recombinant phytase are respectively 55 ℃ and 4.5;The purified recombinant phytase can tolerate high temperature at 60 ℃ and has a good stability within pH 3—7.5;The phytase whose activity is inhibited by Cu2+,Zn2+ and Fe3+ has characteristics resistant to trypsin and pepsin.