Biopolymers and cell. 1986. Volume 2. № 6. 293 - 301
V. A. Noskin, G. E. Shmelev, A. V. Lomakin, L. G. Petroua-Mastakova, N. S. Parfenova, E. V. Belova, A. N. Klimov
HIGH DENSITY LIPOPROTEIN CONFORMATION CHANGES IN THE PROCESS OF SATURATION BY CHOLESTEROL
Summary
By means of quasielastic light scattering the size of human high density lipoproteins (HDL3) has been determined depending on the time of their incubation with erythrocytes both in the presence of the lecitin-cholesterol-acyltransferase inhibitor (DTNB) and without it. It has been shown that in the presence of DTNB the exchange of cholesterol between HDL3 and membranes of erythrocytes is a first-order reaction. From the temperature dependence of rate constant the activation energy of cholesterol exchange Ea = 6.5+-0.2 kkal/mol has been calculated. The reaction rate appears to be proportional to membrane concentration, which evidences in favour of contact transfer of cholesterol. In the absence of DTNB the cholesterol exchange has a more complicated kinetics. An attempt has been made to explain the behaviour of HDL3 average size during incubation with erythrocytes both in the presence of DTNB and without it.