Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Nakamura, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nakamura, M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1990, Vol. 108, No. 2 245-249
© 1990 Japanese Biochemical Society

research-article

One-Electron Oxidation of Trolox C (a Vitamin E Analogue) by Peroxidases

Masao Nakamura

Division of Biophysics, Research Institute of Applied Electricity, Hokkaido University Kita-ku, Sapporo, Hokkaido 060

The oxidation mechanism of Trolox C (a vitamin E analogue) by peroxidases was examined by stopped flow and ESR techniques. The results revealed that during the oxidation of Trolox C, peroxidase Compound II was the catalytic intermediate. The rate constants for the reaction of Compound II with Trolox C, which should be the rate-determining step, were estimated to be 2.1x104 and 7.2x103 for horseradish peroxidase and lactoperox idase, respectively, at pH 6.0. The formation of the Trolox C radical was followed by ESR. The time course of the signal was similar to that of the optical absorbance changes at 440 nm, assigned as the peak of the Trolox C radical. The signal exhibited a hyperfine structure characteristic of phenoxyl radicals. From an estimation of the radical concentration in the steady state and the velocity of the radical formation, the dismutation constant was calculated to be 5x10 5 M–1·S–1. The concentration of the signal in the steady state was reduced by the addition of GSH. The spectrum changed from that of the Trolox C radical to that of the ascorbate radical when the reaction was carried out in the presence of ascorbate.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Drug Metab. Dispos.Home page
K. He, R. E. Talaat, and T. F. Woolf
INCORPORATION OF AN OXYGEN FROM WATER INTO TROGLITAZONE QUINONE BY CYTOCHROME P450 AND MYELOPEROXIDASE
Drug Metab. Dispos., April 1, 2004; 32(4): 442 - 446.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.