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Structural changes of low density lipoproteins with Cu 2+ and glucose induced oxidation
Author(s) -
GallegoNicasio J.,
LópezRodríguez G.,
Martínez R.,
Tarancón M. J.,
Fraile M. V.,
Carmona P.
Publication year - 2003
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10486
Subject(s) - chemistry , low density lipoprotein , autoxidation , copper , lipid oxidation , lipoprotein , conjugated system , organic chemistry , biochemistry , antioxidant , cholesterol , polymer
The compositional and structural changes of lipids and apolipoproteins during in vitro oxidation of low density lipoprotein (LDL) are investigated in this study by IR spectroscopy. For comparison, LDL samples containing either copper or glucose at physiological or pathological concentrations are considered in order to know the separate affects of these chemical factors on LDL oxidation. The results show that the initial steps of lipid oxidation proceed through hydrogen atom loss from methylene groups, as well as loss of cholesteryl ester molecules, and later a recovering of carbonyl compounds resulting from aldehyde formation that generally occurs in autooxidation processes. Lipid oxidation is induced by copper ions, and glucose enhances metal ion induced LDL oxidation as determined by conjugated diene formation. As to the protein conformational changes, IR spectroscopy reveals for the first time that LDL oxidation involves formation of β‐sheet structures, these being more abundant in LDL samples with pathological concentrations of glucose or copper. Consequently, the LDL structural changes may contribute to the recognition of oxidized LDL particles by scavenger receptors. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 72: 514–520, 2003