Shapes of Plasma Membrane Vesicles and PC-Cholesterol Vesicles Reveal Their Effective Spontaneous Curvature

Giant membrane vesicles (GUVs) and giant plasma membrane vesicles (GPMVs) are useful models for studying cellular membrane properties. Our research analyzed the reduced volume of vesicles made from phospholipid and 10% cholesterol to investigate transbilayer sugar asymmetries. We found that GPMVs have an average reduced volume of (0.88 {+/-} 0.06) with buffer asymmetry of 323 mM, lower than the (0.92 {+/-} 0.08) observed for DOPC: cholesterol vesicles with sucrose/glucose asymmetry of 390 mM. GUVs with different sugars inside and outside were more deflated, demonstrating a greater volume reduction than those with the same sugar inside and out. We applied the area-difference elasticity (ADE) model to map GPMVs and used the spontaneous curvature (SC) model to analyze DOPC: cholesterol GUVs, extracting spontaneous curvature based on their reduced volume. TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=178 SRC="FIGDIR/small/622000v1_ufig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@178828forg.highwire.dtl.DTLVardef@c38f8eorg.highwire.dtl.DTLVardef@105c783org.highwire.dtl.DTLVardef@6da36d_HPS_FORMAT_FIGEXP M_FIG C_FIG