Studies on the induced synthesis of beta-galactosidase in Escherichia coli: the kinetics and mechanism of sulfur incorporation. 1955.

Abstract

Abstract A study of the kinetics of sulfur incorporation into the molecule of β-galactosidase during the induced synthesis of this enzyme in E. coli brings proof that the enzyme-protein is synthesized entirely de novo without any appreciable participation of materials coming from other cellular proteins. Furthermore, there is no measurable renewal of β-galactosidase sulfur in growing cells whether or not the enzyme is being synthesized. The induced synthesis of β-galactosidase appears as a virtually irreversible process. The bulk of the other cellular proteins in E. coli are equally stable and do not undergo any appreciable degradation and resynthesis during growth. The apparent contradiction between these results and the generally accepted concepts regarding the dynamic state of intracellular proteins is discussed.