To survive, living organisms have adapted to a wide range of environments, even those with extreme conditions such as the deep sea. Recently Winnikoff et al. presented the “homeocurvature adaptation” mechanism for ctenophores. This adaptation allows these invertebrate animals to maintain the fluidity and dynamism of their membranes at high pressures by synthesizing plasmalogen lipids in extraordinary amounts. Membrane lipid phase behavior and spontaneous curvature were affected by the abundance of plasmalogen lipids, which are characterized by a vinyl-ether linkage at the sn-1 position of the glycerol backbone. To understand the influence of different backbone linkages on the lipid bilayer, we used high-pressure (Hi-P) MD simulations to study the effect of ester and ether-linked lipids on membrane elastic properties. We have discovered that the difference in the structure of these lipids causes differences in the hydration of the head group, which translate into changes in the curvature and stiffness of the membrane. Comparison with Hi-P SAXS measurements suggests that membrane curvature extracted from MD simulations has a qualitatively correct pressure dependence, showing that ester lipids have a tendency to prefer lower curvature geometries, while ether lipids prefer higher curvature geometries.
Urbano et al. (Sun,) studied this question.