Using pulse radiolysis, the rate constant for the reaction of ferric myeloperoxidase with O2- to give compound III was measured at pH 7.8, and values of 2.1 · 106 M-1 · s-1 for equine ferric myeloperoxidase and 1.1 · 106 M-1 · s-1 for human ferric myeloperoxidase were obtained. Under the same conditions, the rate constant for the reaction of human ferric myeloperoxidase with H2O2 to give compound I was 3.1 · 107 M-1 · s-1. Our results indicate that although the reaction of ferric myeloperoxidase with O2- is an order of magnitude slower than with H2O2, the former reaction is sufficiently rapid to influence myeloperoxidase-dependent production of hypochlorous acid by stimulated neutrophils.
|Number of pages||5|
|Journal||Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular|
|Publication status||Published - 31 Aug 1988|
- Hydrogen peroxide
- Pulse radiolysis