Expression in Escherichia coli of a cytochrome P450 enzyme with a cobalt protoporphyrin IX prosthetic group.

Unlike many hemoproteins, the prosthetic heme group of most cytochrome P450 enzymes cannot be extracted and replaced by modified heme groups. Here, we describe a procedure for generating a cytochrome P450 enzyme (CYP119) with cobalt protoporphyrin IX as its prosthetic group. This is achieved by expressing the protein in Escherichia coli in iron-limited medium and adding cobalt to the medium at the moment that inducible protein expression is initiated.