Supplementary Figure 5: Amide secondary chemical shifts of rdHDL are indicative of bent helices.
(a) The amide secondary chemical shifts (δΔ1HN), i.e. the experimental chemical shifts of rdHDL minus the corresponding ‘random coil’ shifts, are shown along the amino acid sequence. The black connected dots are experimental data, while the red lines symb›olize the wave-like pattern of the helices. In addition, Pro residues with their sequential neighbor i+1 as well as aromatic residues are specifically labeled, since aromatic ring-currents and prolines can change amide proton shifts. The dashed lines indicate residues with the assigned heptad letter ‘a’ and ‘d’. The wave pattern is attributed to the curvature of the helices, allowing the solvent and lipid-facing side of the helices to be determined. In the proposed modified heptad sequence (abc[c’]defg), letters ‘a’ and ‘d’ are pointing towards a hydrophobic interface (i.e., the lipid bilayer). (b) the amino acid sequence of MSPΔH5 with the highlighted heptad sequence (abc[c’]defg), with ‘a’ and ‘d’ underlined. (c) The amide secondary chemical shifts (δΔ1HN) of rdHDL in DMPC (black) and POPC (red) overlap almost perfectly, indicating a similarity of the structure, regardless of the used lipid.
