Hydrogen Ion-induced Reversible Inactivation and Dissociation of Formyltetrahydrofolate Synthetase

Hydrogen ion-induced reversible inactivation and dissociation of formyltetrahydrofolate synthetase.

Formyltetrahydrofolate synthetase undergoes inactivation at pH values below 7. Inactivation is accompanied by both the dissociation of the tetramer into monomers and the exposure of aromatic amino acids to the solvent. The rate of inactivation is a function of pH. This rate and the rate of exposure of tryptophan residues to the aqueous environment follow first order kinetics. After prolonged in...

Reversible inactivation and dissociation of yeast hexokinase.

Recent’ work on the reactivation and reconstitution of several denatured enzymes has provided increasing understanding of the process of reversible protein denaturation. Studies on ribonuclease by Anfinsen et al. (1) and White (2) have convincingly demonstrated that under favorable conditions a complet,ely denatured protein can resume the active three-dimensional configuration of the native mol...

Reversible inactivation by hydrogen peroxide

Dissociation energies of molecular hydrogen and the hydrogen molecular ion.

We have obtained improved values for the dissociation energies of molecular hydrogen and its ion by using a high-resolution pulse-amplified laser to probe the second dissociation limit. The onset of the vibrational continuum is observed by state-selective detection of the atomic products of dissociation, and several auxiliary measurements link the results to the ground state. The dissociation e...

Distribution of 10-formyltetrahydrofolate synthetase in eubacteria.

The distribution of 10-formyltetrahydrofolate synthetase, which activates formate for use as a one-carbon donor in a variety of biosynthetic reactions, was determined for a variety of eubacteria. Organisms from several genera were found to lack detectable synthetase activity; however, all organisms tested were found to contain 5,10-methylenetetrahydrofolate dehydrogenase activity.