Fish the Oxygen Intermediates

II . The Role of Oxygen Intermediates

In the accompanying report (1), we demonstrated that Toxoplasma gondii, an obligate intracellular parasite, is susceptible to oxygen intermediates generated by the xanthine oxidase system. The present study examines the contribution of oxidative metabolites to macrophage killing and inhibition of growth of intracellular T. gondii. Our observations indicate that an oxygen-dependent antimicrobial...

SnapShot: Reactive Oxygen Intermediates (ROI)

Haem-oxygen reactive intermediates: catalysis by the two-step.

The catalytic schemes of a variety of haem enzymes, including the P450 mono-oxygenases, consist of a number of common reactive haem-oxygen adducts. The characterization of these intermediates by optical and EPR spectroscopies has reinforced the similarity of these intermediate states in a number of haem enzyme systems. Furthermore, the reactivity of these states in P450 and horseradish peroxida...

Macrophage oxygen-dependent antimicrobial activity. II. The role of oxygen intermediates

The capacity of three populations of mouse peritoneal macrophages to generate oxidative metabolites (as judged by extracellular release of H2O2) was compared to their ability to influence the intracellular fate of virulent Toxoplasma gondii. Macrophages from normal mice released little H2O2 and allowed unrestricted multiplication of intracellular toxoplasmas. Cells from chronically infected, im...

Redox transitions between oxygen intermediates in cytochrome-c oxidase.

Some intermediates in the reduction of O2 to water by cytochrome-c oxidase have been characterized by optical, Raman, and magnetic circular dichroism spectroscopy. The so-called "peroxy" (P) and "ferryl" (F) forms of the enzyme, which have been considered to be intermediates of the oxygen reaction, can be generated when the oxidized enzyme reacts with H2O2, or when the two-electron reduced ("CO...