title: Sequential change in physicochemical properties of LDL during oxidative modification.
abstract: Oxidized LDL is thought to be a highly atherogenic lipoprotein. Structural background of this pathogenesis, however, has not yet been well defined. Physicochemical characterization of this lipoprotein is still controversial, which therefore makes it difficult to take a mechanistic approach to its atherogenicity. We thus conducted investigation of time-dependent changes in chemical compositions and alternation of physical properties of LDL in detail during its oxidation induced by human embryonic endothelial cells and copper ions. The oxidation caused hydrolysis of glycerolipids being demonstrated as decrease of triglyceride and choline-phospholipid and increase of lysophosphatidylcholine. Fragmentation of apoB was also induced while over-all protein components stayed with the particles. The density of the particles continuously shifted to higher fractions for all the particles to reach d ≥ 1.044 after 10h incubation. The average diameter of LDL, however, decreased from 28.1 nm to 25.6 nm by 5h and increased to 27.1 nm towards 20 h incubation with the increase of discoid particles. These dynamic changes can be interpreted by losing fatty acyl group from the core lipid components perhaps due to oxidative degradation and by increase of surface lysophosphatidylcholine to cause remodeling of the particles.
authors.affiliation: Institute of Environmental Science of Human Life, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Kido
authors.affiliation: Department of Food and Nutritional Science, Toyo University, Itakura-machi, Ora-gun, Gunma 374-0193, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kondo
authors.affiliation: Shinagawa East One Medical Clinic, Minato-ku, Tokyo 108-0075, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Itakura
authors.affiliation: Nutritional Health Science Research Center, Chubu University, Kasugai 487-8501, Japan. Electronic address: syokoyam@isc.chubu.ac.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D001055:Apolipoproteins B / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008077:Lipoproteins, LDL / Q000737:chemistry*; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000737:chemistry
chemical_list: D001055:Apolipoproteins B; D008077:Lipoproteins, LDL; D010743:Phospholipids; C099252:oxidized low density lipoprotein; D003300:Copper; D002784:Cholesterol
keywords: Apolipoprotein B; Cholesterol; Copper ion; LDL; Oxidation; Phospholipid