Effects of valine on protein synthesis and turnover in Pseudomonas saccharophila under "nongratuitous" inducing conditions.

Under "nongratuitous" inducing conditions, in Pseudomonas saccharophila, d-and l-valine and l-isoleucine inhibit net protein synthesis. At a concentration of 0.5 mumole or greater of valine per mg of bacterial protein, net protein synthesis declined approximately 70%. The inhibitory effect of valine is proportional to the exogenous valine concentration. Studies of (14)C amino acid incorporation and (14)C amino acid release from prelabeled cells indicate that valine stimulates protein turnover.