Formation of high-molecular-weight protein adducts by methyl docosahexaenoate peroxidation products.
In the present study, the formation of modified proteins by methyl docosahexaenoate (DHA) peroxidation products in the presence of a metal-catalyzed oxidation system was investigated. Metal-catalyzed oxidation of mixtures containing bovine serum albumin (BSA) and DHA led to formation of two high molecular weight derivatives of BSA. One had a mass of 71.5 kDa as determined by two-dimensional electrophoresis, matrix assisted laser desorption and ionization mass spectrometer (MALDI MS) analysis. The other was estimated to be 93 kDa by SDS-PAGE electrophoresis. The exposure of BSA to DHA also led to the generation of carbonyl groups. Oxygen radical scavengers could inhibit these modifications induced by DHA peroxidation. Furthermore, there was little difference of the peptides mass fingerprinting between the two kinds of modified high-molecular-weight proteins. These results suggest that oxygen radicals formed during lipid peroxidation are involved in the formation of protein derivatives. Our study may be important in the understanding the specific role of docosahexaenoic acid in the formation of modified proteins during aging and its related diseases.
Liu
Wei
W
Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
Wang
Hua-Jie
HJ
Wang
Li-Ping
LP
Liu
Shan-Lin
SL
Wang
Jin-Ye
JY
D015153:Blotting, Western; D004281:Docosahexaenoic Acids / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D004591:Electrophoresis, Polyacrylamide Gel; D016166:Free Radical Scavengers / Q000737:chemistry; D015227:Lipid Peroxidation; D008970:Molecular Weight; D011506:Proteins / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D016166:Free Radical Scavengers; D011506:Proteins; D004281:Docosahexaenoic Acids; C059579:methyl docosahexaenoate