title: Role of oxygen and metal ions in the instability of streptolysin O.
abstract: Thiol-containing preparations of streptolysin O (SLO) and pure cysteine generate superoxide radicals in alkaline buffer on autoxidation of the thiol groups. Autoxidation is stimulated by cupric ions. Reconstituted SLO preparations accumulate hydrogen peroxide with a concomitant loss of activity on storage at room temperature. Short-term protection of hemolytic activity was achieved by inclusion of catalase in the preparation; no apparent protection was observed by superoxide dismutase, whereas 1,10-O-phenanthroline offered long-term protection of the hemolysin.
authors.affiliation: Department of Pharmaceutics/Microbiology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
authors.forename: H A
authors.initials: HA
authors.lastname: Shoeb
mesh_terms: D001426:Bacterial Proteins; D006461:Hemolysis; D006801:Humans; D007700:Kinetics; D008670:Metals / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D013301:Streptolysins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008670:Metals; D013301:Streptolysins; C025964:streptolysin O; D010100:Oxygen