Structural and Oxidation Properties of Plasma Lipoproteins from Different Phenotypes: FT-IR and ESR Study

Subclasses of lipoproteins VLDL, LDL and HDL were isolated from plasma of two different phenotypes, A and B. Phenotype B is present in people with diabetes, atherosclerosis and higher risk for cardiovascular disease. Lipoproteins were studied by FT-IR spectroscopy to investigate conformational and structural differences reflected in spectra. Differences were observed in spectra of LDL and VLDL. In protein domain differences were observed in amide I band profile and discussed in terms of conformational change of apo B-100 in small LDL and large VLDL particles. The changes in lipid bands from phenotype B are associated with differences in core composition and lipids' ordering in monolayer. The study of slow oxidation was done by measuring the oxygen consumption in lipoprotein solutions. Oxidation was faster in HDL and VLDL from phenotype B, while for LDL it was similar for A and B samples and significantly faster than in other two lipoproteins. (doi: 10.5562/cca2236)