Degradation of Abnormal Proteins in Escherichia Coli: In Vitro Proteolysis of Cyanogen Bromide Peptides

Abstract

Exposure of E. coli to the antibiotic puromycin hydrochloride results in the synthesis of shortened polypeptide, which is rapidly degraded unlike protein of normal chain length (1,2). However, the mechanism by which the cell differentiates between normal length and the puromycin-induced prematurely terminated polypeptide to degrade specifically the latter is not understood. In an attempt to gain some insight into this process, we have produced shortened polypeptide in vitro and then examined the degradability of the resultant polypepetide in E. coli cell-free extracts.