THE MECHANISM OF THE SYNTHESIS OF ENZYMES : I. DEVELOPMENT OF A SYSTEM SUITABLE FOR STUDYING THIS PHENOMENON

1. An experimental system suitable for the study of enzyme formation has been described. 2. The formation of β-galastosidase in E. coli B could be induced by lactose, melibiose, D-galactose and β-methyl-D-galactoside. 3. Lactose-induced β-galactosidase formation was found to be inhibited by D-glucose, D-mannose, D-fructose, D-arabinose, and raffinose. 4. The utilizable structural analogue, D-glucose, was found to either stimulate or inhibit β-galactosidase formation depending upon its concentration. D-Arabinose, on the other hand, a non-utilizable structural analogue, is only capable of inhibiting, whereas succinic acid, a structurally unrelated energy source, is only capable of stimulating β-galactosidase formation. 5. D-Arabinose inhibition of lactose-induced β-galactosidase formation was found to be of the competitive type. 6. Some of the implications of these findings have been discussed.