Overproduction and purification of the CcpA protein from Lactococcus lactis.

In this work we present cloning and overexpression of lactococcal CcpA protein in Escherichia coli Xl1blue strain as a fusion with 6×His tag. A high yield of the CcpA protein was obtained when the cells were cultured in liquid medium LB with 100 Μg/ml ampicillin at 37°C and subsequently for 4 h after induction by IPTG. The procedure let us obtain 5 mg of homogenous CcpA protein. Glutaraldehyde crosslinking analysis indicated the formation of dimer or tetramer forms of the CcpA protein.