Expression of human leukotriene A4 hydrolase cDNA in Escherichia coli

Abstract

The cDNA clone encoding human leukotriene A₄ hydrolase was inserted into a vector pUC9 and expressed in Escherichia coli as a fusion protein containing the first 10 amino acid residues derived from a vector. The leukotriene A₄ hydrolase activity was recovered in the soluble fraction of the transformants. The purified enzyme showed kinetic properties similar to the native enzyme, including inactivation by the substrate and sulfhydryl‐modifying reagents. The results demonstrate that a protein with an M _r of 70000 was expressed in Escherichia coli with a full enzyme activity and structural fidelity. Acquisition of the expression system makes it feasible to elucidate the reaction mechanism of the enzyme.