Research Paper Volume 5, Issue 7 pp 551—574

Figure 7. LCA reduces the relative levels of non-bilayer forming glycerophospholipids and elevates the relative levels of their bilayer forming species.

(A) Relative sizes of the cross-sectional areas of hydrophilic head group for different glycerophospholipid species. (B) Saturated and unsaturated hydrophobic acyl chains of glycerophospholipids. (C) The shape of a glycerophospholipid molecule (i.e., the bilayer forming shape of a cylinder, the non-bilayer forming shape of a cone or the non-bilayer forming shape of an inverted cone) is defined by the relative sizes of the cross-sectional areas of its hydrophilic head group and hydrophobic acyl chains. See text for details. (D) The relative levels of cylinder-, cone- and inverted cone-shaped glycerophospholipids in a membrane define membrane curvature, including that of the IMM. See text for details. (E - H) Cells were cultured in the nutrient-rich YP medium initially containing 0.2% glucose with 50 μM LCA or without it, in the presence of 1% DMSO (E and G) or in its absence (F and H). Mitochondria were purified from cells recovered on day 2, 4 or 7 of cell culturing. Extraction of mitochondrial membrane lipids, and mass spectrometric identification and quantitation of the glycerophospholipid species were performed as described in Methods. Based on these data, the relative levels of non-bilayer forming and bilayer forming glycerophospholipids (see C) were calculated as mol% of all membrane glycerophospholipids. Data are presented as means ± SEM (n = 3; *p < 0.01).