Purification of Recombinant S-layer Protein fromLactobacillus brevis and Preliminary Identification of Adhesive Property in Vitro

Slp gene was subcloned by PCR from the plasmid of pMD19T-slp constructed in our laboratory,and inserted into the prokaryotic expression vector of pGEX-4T-3,so the prokaryotic expression vector of pGEX-slp was successfully constructed.Recombinant fusion protein of GST-SLP was gained by IPTG induction and purified by LiCl method.Then,expression products were identified by SDS-PAGE and Western blot.And the adhesive property of recombinant fusion protein was identified by ELISA method invitro.In cracked samples of E.coli BL21,both the SDS-PAGE and Western blot proved that the presence of the fusion protein GST-SLP which had a molecular weight of approximately 71ku.The ELISA results suggested that the recombinant fusion protein could effectively adhere to the surface of Lactococcus lactis NZ9000 in vitro.These experiments lay a foundation for further study on the biological characteristics of the S-layer protein.