The enzymatic synthesis of protein. I. The sythesizing action of pepsin

A condition in which a synthesis of protein-like material occurs, was first arranged in 1886 by Danilewski (1) who observed the formation of a precipitate when stomach extract was added to a concentrated solution of the products of peptic hydrolysis. He considered the causative agent to be an enzyme, because precipitation did not occur if the stomach extract had been previously heated to 100°C. This result was confirmed in 1895 by Okunew. Both Danilewski and Okunew concluded that the reaction involved synthesis of the products of protein decomposition into a more composite molecule approaching in complexity a native protein.