Prokaryotic expression, purification and identification of lactate dehydrogenase from schistosome japonicum

Objective To express SjLDH in prokaryotic expression system,purify and identify the protein expressed.Methods The encoding fragment of SjLDH was inserted into plasmid pET-28a and the recombiant plasmid p ET2-8a-SjLDH was transformed into E.coli BL21 and induced by IPTG.The expressed products were purified by affinity chromatography column and identified by SDS2PAGE,Western blot,EL ISA,enzymatic vital staining and enzymatic activity detection.Results Recombinant plasmid p ET2-8a-SjLDH was constructed and expressed in E.coli successfully.A 362kDa protein with 6×His-tag was purified by affinity column and identified by SDS-PAGE and Western blot,which had high LDH activity of 379 U/mg and high immunological activity.Conclusion Recombinant SjLDH was obtained successfully,which had high enzymatic activity and immunological activity.This work provided the essential material for the functional study on SjLDH.