The Action of Atomic Hydrogen on Bovine Carbonic Anhydrase in Aqueous Solution

Abstract

The action of atomic hydrogen on bovine carbonic anhydrase in aqueous solution has been investigated at different total doses of H atoms. The rate of inactivation of the enzyme is (5.0 ± 0.5) × 107 liter mole−1 s−1. Concurrent with the inactivation of the enzyme, specific changes in the ultraviolet absorption spectrum have been observed. The observed decrease of the 280 nm absorption peak is consistent with attack on the tryptophan residues. H atoms were found to react faster with apocarbonic anhydrase than with the native enzyme. Sulfonamide inhibitor did not protect the tryptophan residues in the enzyme from the action of hydrogen atoms.