Protein Synthesis

Substrate hydrolysis has been the usual criterion of autolytic activity. On theoretical grounds we assume the reaction to be reversible and under proper conditions to lead to the synthesis of protein molecules from cleavage products. The experimental evidence for such reversals is obviously extraordinarily difficult to obtain in a tissue brei. Without the organization of the cell to protect and insure stability of a peptide chain once formed in order that it may go on to the next step in synthetic growth, the possibility of building up a native protein molecule seems remote.

Where the environment of the tissue extract, glutathione and cleavage products was changed from anaerobic to aerobic conditions. There have been a few other reports of similar successful syntheses. There have also been failures reported. Perhaps the most convincing demonstration of synthesis that liver or spleen cathepsin can catalyze the synthesis of a single specific peptide bond by the use of a well defined simple substrate. This experiment we believe finally completes the evidence which establishes the validity of the major concepts of the autolytic mechanism as functional in both atrophic and hypertrophic tissue changes.