Calvo C, Ulloa N, Del Pozo R, Verdugo C
Departamento de Bioquímica Clínica e Immunología, Facultad de Farmacia, Universidad de Concepción, Chile.
Eur J Clin Chem Clin Biochem. 1993 Apr;31(4):217-20. doi: 10.1515/cclm.1993.31.4.217.
Non-enzymatic glycation of plasma proteins may contribute to the excess risk of developing atherosclerosis in patients with diabetes mellitus. Glycated apolipoprotein A-I isolated from diabetic subjects was tested in vitro for its ability to activate lecithin:cholesterol acyltransferase, the principal cholesterol-esterifying enzyme in plasma. Activation by glycated apolipoprotein A-I was significantly lower at all concentrations than the activation by normal apolipoprotein A-I. Linear regression analysis of the kinetic data shows that the ratio app Vmax/app Km was significantly lower (p < 0.01) for glycated apolipoprotein A-I (0.29 nmol.l/h.mumol) than for normal apolipoprotein A-I (0.78 nmol.l/h.mumol). Because lecithin:cholesterol acyltransferase provides a driving force in reverse cholesterol transport by esterifying the cellular cholesterol removed by HDL, it is tempting to postulate that this abnormal activation may be associated with a reduction in reverse cholesterol transport and associated with the accelerated development of atherosclerosis in diabetic patients.
