In vitro production of reactive oxygen species by a histatin, copper (II), and ascorbic acid system

BIOL 10

Eric Houghton, houghton@ou.edu and Kenneth M. Nicholas, KNicholas@ou.edu. Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
Histatins are histidine-rich, short chain, salivary polypeptides. They exhibit antifungal properties, particularly against Candida albicans and related yeasts, and are also known to bind metals, primarily zinc and copper. Reactive oxygen species (ROS) have been both implicated and refuted for the antimicrobial properties of the histatins, as their molecular mechanism has not been ascertained. This presentation is part of a study of the global structure and reactivity of the hist-5 and hist-8. We have observed ROS production by a histatin / ascorbate / O2 / Cu system and spectral changes from NMR upon Cu(I) titration. These results and their interpretation vis à vis the specific ROS generated, the involvement of histatin – Cu complexes, and their possible biological significance will be presented.