Schaefer - Figure 5 - Composition of HDL particles Text

This Figure recreates the information in the 2-D electrophoresis gel as a cartoon, showing the composition of this spectrum of HDL particles, for which the major protein is apoA-I. As can been seen, at the bottom are the very small precursor (pre-beta1) particles, which are discs of lipoprotein with 2 molecules of apoA-I and a molecular weight of about 60 kiloDaltons (KD). As these discs enter the circulation and begin to take up cholesterol, they become the very small, discoidal alpha4 HDL particles; these also have 2 molecules of apoA-I, but now they contain some cholesterol.

As these particles continue to circulate, they become larger and larger, accumulating additional cholesterol via complex chemical actions involving lecithin and cholesterol acyltransferase (L-CAT), which esterifies the cholesterol, until they become the largest alpha1 HDL particles, fully charged with cholesterol.

Schaefer E. J Clin Lipidol. 2011; 5(6).