A Novel Expression System for Production of a Labile Protein in Escherichia coli by infection with Cytosin-substituting T4 Phage.

Abstract

A novel expression system was developed for the high level production of a labile protein in Escherichia coli. The regulatory signal of bacteriophage T4 uvsY gene was fused in frame with the coding region of human ventricular myosin alkali light chain (VLC1) gene. Expression from the regulatory signal was enhanced and continued in a lysis-inhibition state by infection with a cytosine-substituting T4 phage mutant. VLC1 protein was produced at a low level without infection because of its instability in the cells. Although the productivity was partly improved in a lon-deficient mutant without infection, it was improved about 100-fold with T4 phage infection. T4 phage produces protease inhibitor(s) (pin gene product) against proteases of host cell including the lon gene product (protease La).