Functional Expression Of Panicillium Expansumlip Ase Gene In Ecoliand Function Analysis

Penicillium expansum lipase (PEL) is a kind of carboxyl group esterase thatcatalyzes hydrolysing long chain acylglycerol. The lipase has biological catalysischaracteristic in both the aqueous phase medium and the non-aqueous phase medium.PEL is widly used catalysts in eater reaction, and it is the only one of China that wasproduced in factory.Prokaryotic expression is one path to optimize PEL in trangenetic methods, but itshows no enzyme activity through this path.In this research, the lipase gene pel was amplified from the RNA of Penicilliumexpansum by RT-PCR, and then was constructed to the plasmid pET-28a(+).The recombinant plasmid pET-28a(+)-pel was tranformed into E.coli BL21, andthen was expressed both in 15℃and 37℃. It was found that the expression yield inlow temperature and long period was higher.Co-transformed with each of the chaperones plasmids pGro7,pG-Tf2,pTf16,pKJE7 and pG-KJE8 and we obtained recombinant E.coli with effective functionalexpression of PEL. Each strain showed enzyme activity after low temperature (15℃)induction, and the detailed analysis indicated that chaperone potein GroEL and Tfplayed great effect on the PEL's activity. The expression of PEL and chaperoneprotein was also verified by SDS-PAGE. This is the first report on the functionalexpression of PEL in E. coli, and it offers a good way in high-throughput screeningafter random mutation.