Glycosylated β-lipoprotein, Diabetes Mellitus and Atherosclerosis

Abstract

β-lipoprotein plays an important role in atherosclerosis, which is the major cause of morbidity and mortality in diabetics. The rapid clearance of LDL from plasma is dependent on a receptor binding with apoprotein B, the major protein of LDL particle, which is present on cell membrane. It has been demonstrated that chemical modification of lysine groups on apolipoprotein B interfers with the ability of LDL to bind to the high affinity receptor. It has been demonstrated that glycosylation of LDL would block lysine groups and lead to inhibition of the ability of LDL to interact with the LDL receptor.
The purpose of this presentation is to review our knowledge of non-enzymatic glycosylaton of β-lipoprotein with particular reference to method of measurement, of glycosylated β-lipoprotein.
Glycosylated β-lipoprotein was measured by affinity column chromatography. Following results were obtained.
1. Elevated glycosylated β-lipoprotein has been found in diabetes mellitus (DM).
2. There were good correlations between β-lipoprotein and total cholesterol or GHb in DM.
3. The catabolic rate for the glycosylated β-lipoprotein was lower than that of non-glyco-sylated β-lipoprotein in vivo.
4. Acetyl salicylic acid or pyridoxal phosphate competitively inhibited glycosylation of β-lipo-protein.
5. Glycosylated β-lipoprotein injured vasucular endothelial cells in vivo.