D-Ribose Glycation of Human High-Density Lipoprotein: Structural and Functional Alterations

Glycation of biomolecules leads to the formation of advanced glycation end products (AGEs) and is implicated in molecular mechanisms of human chronic diseases. We compared the glycation properties of D-ribose and methylglyoxal on human high-density lipoprotein (HDL). The increase in fluorescent AGEs in HDL samples treated with methylglyoxal confirms that HDLs are sensitive to glycation treatment. Our results demonstrated that even D-ribose glycates HDL as shown by changes induced by D-ribose on HDL apoprotein. Biochemical markers of lipid and protein oxidative damage were also evaluated. The increase in protein carbonyl contents and thiobarbituric acid reactive substances (TBARS) demonstrates a glyco-oxidative stress occurs in D-ribose treated HDL. In addition, HDL treated with D-ribose showed a significant decrease in the activity of the enzyme paraoxonase 1 and an increased HDL redox activity. These data demonstrate that D-ribose-induced glycation of HDL may impair lipoprotein functionality and may contribute to molecular mechanisms of dysmetabolic diseases.