Expression of rat hepatic glucokinase in Escherichia coli

Rat liver glucokinase was expressed in Escherichia coli by using an expression system based on bacteriophage T7 RNA polymerase. The expressed protein starts with the predicted initiator methionine residue and ends at the appropriate carboxyl terminal residue. It was partially purified by ammonium sulfate precipitation and gel filtration and had kinetic and physical properties similar to the purified rat liver enzyme. The efficient expression of this low abundance hepatic protein in bacteria provides a system for in vitro analysis of mutations of the enzyme.