Creatine as an antioxidant: Mechanism of the reaction between creatine and hypochlorous acid

CHED 806

Karin Brumback, karin-brumback@utulsa.edu, Matthew Thomas, matthew-thomas@utulsa.edu, John DiCesare, john-dicesare@utulsa.edu, and Gordon H. Purser, gordon-purser@utulsa.edu. Chemistry and Biochemistry, The University of Tulsa, 600 S. College Ave., Tulsa, OK 74104
Hypochlorous acid is a potent oxidizing agent produced during phagocytosis. It is known to react indiscriminately with a variety of biomolecules. Creatine, a biological muscle energy source and nutritional supplement, has been proposed as a potential antioxidant toward reactive oxygen species. The antioxidant properties of creatine toward reactive chlorine species have not been reported. To evaluate the potential of creatine to act as an antioxidant toward reactive chlorine, the reaction between creatine and hypochlorous acid has been studied using stopped-flow kinetics under buffered conditions between pH 4 and pH 10. Under basic conditions, the kinetic trace indicates the rapid disappearance of hypochlorite ion. However, under acidic conditions, the kinetic trace shows the formation and subsequent reaction of an intermediate. The subject of this presentation includes a proposed mechanism for this system.