Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones

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Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones. / Headlam, Henrietta A; Davies, Michael Jonathan.

In: Free Radical Biology & Medicine, Vol. 32, No. 11, 01.06.2002, p. 1171-84.

Research output: Contribution to journalJournal articleResearchpeer-review

Harvard

Headlam, HA & Davies, MJ 2002, 'Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones', Free Radical Biology & Medicine, vol. 32, no. 11, pp. 1171-84.

APA

Headlam, H. A., & Davies, M. J. (2002). Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones. Free Radical Biology & Medicine, 32(11), 1171-84.

Vancouver

Headlam HA, Davies MJ. Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones. Free Radical Biology & Medicine. 2002 Jun 1;32(11):1171-84.

Author

Headlam, Henrietta A ; Davies, Michael Jonathan. / Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones. In: Free Radical Biology & Medicine. 2002 ; Vol. 32, No. 11. pp. 1171-84.

Bibtex

@article{6b8e3fbd7c5d4c79b66d02bcbe3be3d7,
title = "Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones",
abstract = "Exposure of proteins to radicals in the presence of O(2) results in side-chain oxidation and backbone fragmentation; the interrelationship between these processes is not fully understood. Recently, initial attack on Ala side-chains was shown to give alpha-carbon radicals (and hence backbone cleavage) and formaldehyde, via the formation and subsequent beta-scission, of C-3 alkoxyl radicals. We now show that this side-chain to backbone damage transfer, is a general mechanism for aliphatic side-chains. Oxidation of Val, Leu, and Asp residues by HO(*)/O(2) results in the release of a family of carbonyls (including formaldehyde, acetone, isobutyraldehyde, and glyoxylic acid) via the formation, and subsequent beta-scission of alkoxyl radicals. The concentration of these products increases with the HO(*) flux. The release of multiple carbonyls confirms the occurrence of oxidation at C-3 and C-4 for Val, and these sites, plus C-5, for Leu. The detection of glyoxylic acid and CO(2)(-*) from Asp demonstrates the occurrence of competing beta-scission processes for the Asp C-3 alkoxyl radical. The yield of hydroperoxides and released carbonyls account for 10-145{\%} of the initial HO(*). The greater than 100{\%} yields confirm the occurrence of chain reactions in peptide/protein oxidation, with more than one residue being damaged per initiating radical.",
keywords = "Alcohols, Amino Acids, Electron Spin Resonance Spectroscopy, Free Radicals, Gamma Rays, Hydrogen Peroxide, Nitrates, Oxygen, Peptides, Proteins",
author = "Headlam, {Henrietta A} and Davies, {Michael Jonathan}",
year = "2002",
month = "6",
day = "1",
language = "English",
volume = "32",
pages = "1171--84",
journal = "Free Radical Biology & Medicine",
issn = "0891-5849",
publisher = "Elsevier",
number = "11",

}

RIS

TY - JOUR

T1 - Beta-scission of side-chain alkoxyl radicals on peptides and proteins results in the loss of side-chains as aldehydes and ketones

AU - Headlam, Henrietta A

AU - Davies, Michael Jonathan

PY - 2002/6/1

Y1 - 2002/6/1

N2 - Exposure of proteins to radicals in the presence of O(2) results in side-chain oxidation and backbone fragmentation; the interrelationship between these processes is not fully understood. Recently, initial attack on Ala side-chains was shown to give alpha-carbon radicals (and hence backbone cleavage) and formaldehyde, via the formation and subsequent beta-scission, of C-3 alkoxyl radicals. We now show that this side-chain to backbone damage transfer, is a general mechanism for aliphatic side-chains. Oxidation of Val, Leu, and Asp residues by HO(*)/O(2) results in the release of a family of carbonyls (including formaldehyde, acetone, isobutyraldehyde, and glyoxylic acid) via the formation, and subsequent beta-scission of alkoxyl radicals. The concentration of these products increases with the HO(*) flux. The release of multiple carbonyls confirms the occurrence of oxidation at C-3 and C-4 for Val, and these sites, plus C-5, for Leu. The detection of glyoxylic acid and CO(2)(-*) from Asp demonstrates the occurrence of competing beta-scission processes for the Asp C-3 alkoxyl radical. The yield of hydroperoxides and released carbonyls account for 10-145% of the initial HO(*). The greater than 100% yields confirm the occurrence of chain reactions in peptide/protein oxidation, with more than one residue being damaged per initiating radical.

AB - Exposure of proteins to radicals in the presence of O(2) results in side-chain oxidation and backbone fragmentation; the interrelationship between these processes is not fully understood. Recently, initial attack on Ala side-chains was shown to give alpha-carbon radicals (and hence backbone cleavage) and formaldehyde, via the formation and subsequent beta-scission, of C-3 alkoxyl radicals. We now show that this side-chain to backbone damage transfer, is a general mechanism for aliphatic side-chains. Oxidation of Val, Leu, and Asp residues by HO(*)/O(2) results in the release of a family of carbonyls (including formaldehyde, acetone, isobutyraldehyde, and glyoxylic acid) via the formation, and subsequent beta-scission of alkoxyl radicals. The concentration of these products increases with the HO(*) flux. The release of multiple carbonyls confirms the occurrence of oxidation at C-3 and C-4 for Val, and these sites, plus C-5, for Leu. The detection of glyoxylic acid and CO(2)(-*) from Asp demonstrates the occurrence of competing beta-scission processes for the Asp C-3 alkoxyl radical. The yield of hydroperoxides and released carbonyls account for 10-145% of the initial HO(*). The greater than 100% yields confirm the occurrence of chain reactions in peptide/protein oxidation, with more than one residue being damaged per initiating radical.

KW - Alcohols

KW - Amino Acids

KW - Electron Spin Resonance Spectroscopy

KW - Free Radicals

KW - Gamma Rays

KW - Hydrogen Peroxide

KW - Nitrates

KW - Oxygen

KW - Peptides

KW - Proteins

M3 - Journal article

C2 - 12031901

VL - 32

SP - 1171

EP - 1184

JO - Free Radical Biology & Medicine

JF - Free Radical Biology & Medicine

SN - 0891-5849

IS - 11

ER -

ID: 138278045