CATALYTIC OXIDATION OF SULFHYDRYL GROUPS BY O-PHENANTHROLINE COPPER COMPLEX

1. 1. Catalytic amounts of o-phenanthroline were found to enhance the rate of air-oxidation of all sulfhydryl groups tested in the presence of copper ions at neutral pH. This reaction was prevented by other metal ions which bind o-phenanthroline, as well as by reagents which chelate copper ions. 2. 2. For this reaction, molecular oxygen was essential, one-quarter mole of which was utilized per mole of sulfhydryl group oxidized. 3. 3. The most effective complex as a catalyst of the reaction was found to be (o-phenanthroline)2-Cu2+ complex. Cu+ was detected in the reaction mixture under anaerobic conditions. 4. 4. The interpretation is discussed that o-phenanthroline necessarily acts as a metal chelator in the inhibitory action of this reagent on any enzyme. © 1968.