TY - JOUR

T1 - Reaction between protein radicals and other biomolecules

AU - Østdal, Henrik

AU - Davies, Michael Jonathan

AU - Andersen, Henrik J

PY - 2002/7/15

Y1 - 2002/7/15

N2 - The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2)-activated immobilized horseradish peroxidase (im-HRP). Subsequently, each of the three different biomolecules was separately added to the BSA radicals, after removal of im-HRP by centrifugation. Electron spin resonance (ESR) spectroscopy showed that all three biomolecules quenched the BSA radicals. Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid oil-in-water emulsion resulted in additional formation of lipid hydroperoxides and conjugated dienes. The results clearly show that protein radicals have to be considered as dynamic species during oxidative processes in biological systems and that protein radicals should not be considered as end-products, but rather as reactive intermediates during oxidative processes in biological systems hereby supporting recent data.

AB - The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2)-activated immobilized horseradish peroxidase (im-HRP). Subsequently, each of the three different biomolecules was separately added to the BSA radicals, after removal of im-HRP by centrifugation. Electron spin resonance (ESR) spectroscopy showed that all three biomolecules quenched the BSA radicals. Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid oil-in-water emulsion resulted in additional formation of lipid hydroperoxides and conjugated dienes. The results clearly show that protein radicals have to be considered as dynamic species during oxidative processes in biological systems and that protein radicals should not be considered as end-products, but rather as reactive intermediates during oxidative processes in biological systems hereby supporting recent data.

KW - Animals

KW - Cattle

KW - Electron Spin Resonance Spectroscopy

KW - Free Radicals

KW - Horseradish Peroxidase

KW - Hydrogen Peroxide

KW - Linoleic Acid

KW - Oxidation-Reduction

KW - Peptides

KW - Serum Albumin, Bovine

KW - Spin Labels

KW - Stearic Acids

KW - T-Lymphocytes

KW - Uric Acid

M3 - Journal article

C2 - 12106816

VL - 33

SP - 201

EP - 209

JO - Free Radical Biology & Medicine

JF - Free Radical Biology & Medicine

SN - 0891-5849

IS - 2

ER -