PHYSICAL CHANGES OF LOW-DENSITY-LIPOPROTEIN ON OXIDATION

Human LDL samples from different individuals were oxidized in three di fferent ways. All oxidized LDL samples exhibited lower temperature of the thermotropic transition and lower content of the helical fraction of apoprotein B than the related native LDL. The observed decrease of the thermotropic transition temperature was up to 2 degrees C. The low ering of the transition temperature is qualitatively explained in term s of the 'impurity'-perturbed molecular field in the lipid core. The r eduction of helicity of the apoprotein was drastic; in some samples th e helicity was reduced by more than 50%.