With the advent of recombinant DNA technology, numerous systems have been utilized for the overexpression of proteins. Recombinant protein expression inEscherichia coli (E. coli)typically provides large quantities of the protein of interest in a relatively short period of time. The expression can result in the accumulation of the recombinant protein to levels approaching 30–50% of the totalE. coliprotein. Expression of matrix metalloproteinases (MMPs) inE. colihas proven to be very useful in generating proteins for structural and functional studies, including X-ray crystallography. Numerous MMPs, including altered forms, have been successfully expressed in and purified fromE. coli.These include forms of stromelysin-1, stromelysin-2, stromelysin-3, matrilysin, elastase, collagenase-1, collagenase-3, neutrophil collagenase, and membrane type-1 MMP (1 –20 ). The expression of a truncated form of human stromelysin-1 (SL-1) will be used to illustrate the methods utilized for the expression of a matrix metalloproteinase inE. coliand for its extraction, refolding, and purification
