REGULATION OF BIOSYNTHESIS OF PURINE NUCLEOTIDES IN SCHIZOSACCHAROMYCES POMBE .2. KINETIC STUDIES OF IMP DEHYDROGENASE

1. 1. IMP dehydrogenase was prepared from Schizosaccharomyces pombe. Enzyme kinetics showed properties typical of allosteric enzymes. 2. 2. In the absence of any effector, the substrate NAD exerted homotropic effects. No heterotropic interaction between NAD and substrate IMP was detected. 3. 3. IMP showed neither homotropic nor heterotropic effects. 4. 4. GMP exerted an allosteric effect upon the kinetic of fixation of NAD and showed an homotropic effect for its own fixation. © 1969.