| Autor: |
Vaithianathan Palaniappan, James Terner, C. M. Hosten, M. M. Fitzgerald, A. M. Sullivan |
| Rok vydání: |
1994 |
| Předmět: |
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| Zdroj: |
Springer Proceedings in Physics ISBN: 9783642850622 |
| DOI: |
10.1007/978-3-642-85060-8_58 |
| Popis: |
The catalytic sequences of the heme containing peroxidases involve two high valent intermediates known as compounds I and II [1]. Compound I is two oxidation equivalents above the resting ferric enzyme, and contains an Fe(IV) porphyrin π-radical cation, though cytochrome c peroxidase is a notable exception [2]. Compound II is the one electron reduction product of compound I, with the electron restored to the porphyrin ring, and contains an Fe(IV) heme. Our laboratory has been involved in resonance Raman studies of these intermediates formed by rapid mixing and using laser excitation in the violet and near ultraviolet [3]. Although intermediates similar to compounds I and II are considered to occur in other physiologically important heme enzymes such as cytochrome oxidase and cytochrome P-450, their existence in the catalytic cycles of these enzymes has not been as well documented as for the peroxidases and catalases. The catalases are heme enzymes similar to the peroxidases, which disproportionate hydrogen peroxide. In this account we describe some of our work in progress on the intermediates of horseradish peroxidase and chloroperoxidase. Of the peroxidases, horseradish peroxidase is among the best known because of its commercial availability as a common biochemical reagent. Chloroperoxidase possesses important spectroscopic and structural similarities to cytochro P-450 [4]. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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