Skip to main content
. 2016 Jan 12;6:318. doi: 10.3389/fphar.2015.00318

Figure 4.

Figure 4

Discoidal models of nHDL. In all models the apoA-I chains are shown in cartoon representation and colored with gradient red/blue (Nt = solid color and Ct = faded color). (A) Left: the picket fence model of the apoA-I dimer (Δ43–apoA-I; Jonas et al., 1989; Wald et al., 1990a,b; Nolte and Atkinson, 1992; Phillips et al., 1997); the amphipathic apoA-I α-helices are oriented parallel with the PL molecules. Right: the picket fence model of nHDL (Phillips et al., 1997). The lipid bilayer is made of 144 POPC and 12 FC molecules. (B) Left: computational model of the apoA-I dimer (Δ43–apoA-I) used in the Double Belt model of nHDL proposed by Segrest et al. (1999); the apoA-I chains are oriented antiparallel and stacked on top of each other in helix 5 registry. Right: the Double Belt model of nHDL proposed by Segrest et al. (1999). The lipid bilayer is made of 160 POPC molecules. (C) Left: model of the apoA-I dimer (Δ43–apoA-I) used in the Hairpin model of nHDL proposed by Silva et al. (2005b); apoA-I monomers form semicircular hairpins located at the periphery of the lipid bilayer, which interact through a couple of residues from repeat 5 and the end domain of Ct (V221–Q243). Right: the Hairpin model of nHDL proposed by Silva et al. (2005b). The lipid bilayer is made of 156 POPC and eight FC molecules. (D) Left: model of the apoA-I dimer (Δ43–apoA-I) used in the Looped Belt model of nHDL proposed by Martin et al. (2006); in this model apoA-I features a highly dynamic region (K133–E146) in random coil conformation that extends half of repeat 5 and the beginning of repeat 6. Right: the Looped Belt model of nHDL proposed by Martin et al. (2006). The lipid bilayer is made of 160 POPC molecules. (E) Left: computational model of the full length apoA-I dimer used in the Solar Flare model of nHDL proposed by Wu et al. (2007). Similarly with apoA-I in other belt-type models of nHDL, the apoA-I chains in the Solar Flare model are oriented antiparallel in helix 5 registry. Right: the Solar Flare model of nHDL proposed by Wu et al. (Wu et al., 2007). The lipid bilayer is formed of 200 POPC and 20 cholesterol (FC) molecules. This model of nHDL shows the Nt of apoA-I in a globular conformation.