Non enzymatic glycation of apolipoprotein A-I. Effects on its self-association and lipid binding properties.
In diabetic patients, hyperglycaemia results in the non enzymatic glycation of many proteins including apolipoprotein A-I. We purified glycated apo A-I and compared its lipid binding properties to those of normal apo A-I. Analysis of tryptophan fluorescence spectra and of fluorescence quenching in the presence of iodine showed that glycation of apo A-I induces a decrease in the stability of the lipid-apoprotein interaction and in that of the apoprotein self-association. Repetitive ultracentrifugations of High Density Lipoprotein (HDL) samples containing radioiodinated apo A-I or glycated apo A-I revealed that glycation of the apoprotein facilitates its dissociation from HDL. These results suggest that the non enzymatic glycation of apo A-I may affect the structural cohesion of HDL particles.
D000465:Algorithms; D016632:Apolipoprotein A-I; D001054:Apolipoproteins A / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D050356:Lipid Metabolism; D008075:Lipoproteins, HDL / Q000378:metabolism; D046911:Macromolecular Substances; D013050:Spectrometry, Fluorescence
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D008075:Lipoproteins, HDL; D046911:Macromolecular Substances; D005947:Glucose