Peptidyl transferase substrate activity and inhibition of protein biosynthesis by a hydrophilic-aminoacyl analogue of puromycin

A puromycin analogue possessing a hydrophilic amino acid, 3′-N-[S-(6-hydroxyhexyl)-L-cysteinyl]puromycin aminonucleoside, has been prepared and examined as a substrate for ribosomal peptidyl transferase. Kinetic studies indicate that this non-aromatic aminoacyl analogue is 95.6% as efficient as the parent antibiotic in the transpeptidation reaction. In addition, the analogue is an effective inhibitor of poly (U) and poly (U,C) directed protein synthesis in an Escherichia coli cell free system.