嗜热栖热菌α-葡萄糖苷酶基因的表达及酶学性质研究

Expression and Enzymatic Characterization of Thermus thermophilus α-glucosidase Gene

摘要:

用PCR方法从嗜热栖热菌（Thermus thermophilus）HB27中扩增出编码α-葡萄糖苷酶基因hbg，将其克隆到大肠杆菌（Escherichia coli）表达载体pET28a(+)上，电击转化E.coli BL21（DE3），获得高效表达hbg基因的大肠杆菌重组菌。重组菌经IPTG诱导表达，SDS-PAGE检测表达蛋白相对分子质量约为59kD，与预期分子量相符。经镍柱和阴离子交换柱纯化的重组表达的α-葡萄糖苷酶HBG最适温度为95℃，最适pH值为5.0。

Abstract:

A α-glucosidase gene (hbg) was amplified with PCR from the total DNA of Thermus thermophilus and linked with pGEM-T vector.Hbg gene was inserted into the expression vector pET-28a(+) and transformed into Escherichia coli BL21(DE3) with electroporation，finally the recombinant strain which could efficently secret recombinant α-glucosidase was obtained.Induced by IPTG，the expression products of hbg gene analysed by SDS-PAGE had a molecular mass of 59kD.The optimum temperature and optimum pH of the recombinant expression α-glucosidase were 95℃ and 5.0 respectively.