Prokaryotic expression of streptolysin O antigen and its condition optimization / 国际检验医学杂志

ABSTRACT

Objective To construct the recombinant streptolysin O antigen(SLO) prokaryotic expression plasmid and establish its best expression condition in Escherichia coli .Methods The DNA fragment encoding SLO was amplified from streptococcal ge-nomic DNA template by PCR ,and then incorporated into pET-32a(+ ) vector to construct pET-32a(+ )-SLO recombinant plas-mid .pET-32a(+ )-SLO was transformed into Escherichia coli BL21(DE3) and SLO protein was expressed and purified by isopro-pyl-β-D-thiogalactoside(IPTG)-induction and auto-induction ,respectively .Results The results of DNA electrophoresis and DNA sequencing showed that pET-32a(+ )-SLO recombinant plasmid was constructed successfully .When IPTG at different concentra-tion was used ,SLO expressed as inclusion body and its expression efficiency was low .Under auto-induction condition ,SLO ex-pressed as partly soluble manner ,and its expression efficiency increased .Conclusion The prokaryotic expression plasmid pET-32a (+ )-SLO is constructed successfully and the best condition for SLO expression and purification from Escherichia coli culture is es-tablished ,which lay the foundation for further basic and clinical application research with SLO .