The mechanism by which CETP mediates this “conservation” pathway is not completely understood. The Figure shows a highly plausible schematic that is gaining experimental evidence, and is shown here as a black box. This suggests that CETP interacts with each of the lipoprotein subfractions, exchanges its cholesterol ester, and then dissociates. Because this CETP “cholesterol ester exchange” has no memory of the lipoprotein fraction with which it last interacted, when it next collides with another lipoprotein, it undergoes the same procedure. Ultimately this leads to an equilibration, and that equilibration, for reasons that are a little bit more complicated than needs to be gone into here, leads to a net movement of cholesterol ester from the HDL particles to the VLDL and LDL particles, and thus, from the protective or potentially protective lipoprotein fraction to the potentially harmful lipoprotein fractions.
J Clin Lipidol. 2011; 5(6).