GALACTOKINASE MUTANTS OF CHINESE HAMSTER SOMATIC CELLS RESISTANT TO 2-DEOXYGALACTOSE

Abstract

ABSTRACT The growth of Chinese hamster somatic cells was inhibited by 0.2 mg/cc of 2-deoxygalactose. Mutants partially or fully resistant to 2-deoxygalactose were isolated in a single-step or two-step selection. Some of them did not grow as well as the wild type; one of them which lacked galactokinase (EC.2.7.1.6) activity did not grow at all in galactose medium. The galactokinase kinetic properties (Vmax & Kmax) of the other mutants and of the wild type were different. Therefore resistance resulted either from the possible absence of galactokinase synthesis or from a structural mutation, possibly a missence mutation, in the galactokinase gene.—A simple diagnostic test for juvenile cataract is proposed.