| Autor: |
Fracassi A; Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, California92093, United States., Podolsky KA; Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, California92093, United States., Pandey S; Department of Physics, University of California, San Diego, 9500 Gilman Drive, Mayer Hall Addition 4561, La Jolla, California92093, United States., Xu C; Department of Chemistry, The University of Texas at Austin, 105 E. 24th St. Stop A5300, Austin, Texas78712-1224, United States., Hutchings J; Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California92093, United States., Seifert S; X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois60439, United States., Baiz CR; Department of Chemistry, The University of Texas at Austin, 105 E. 24th St. Stop A5300, Austin, Texas78712-1224, United States., Sinha SK; Department of Physics, University of California, San Diego, 9500 Gilman Drive, Mayer Hall Addition 4561, La Jolla, California92093, United States., Devaraj NK; Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, California92093, United States. |
| Abstrakt: |
Living cells feature lipid compartments which exhibit a variety of shapes and structures that assist essential cellular processes. Many natural cell compartments frequently adopt convoluted nonlamellar lipid architectures that facilitate specific biological reactions. Improved methods for controlling the structural organization of artificial model membranes would facilitate investigations into how membrane morphology affects biological functions. Monoolein (MO) is a single-chain amphiphile which forms nonlamellar lipid phases in aqueous solution and has wide applications in nanomaterial development, the food industry, drug delivery, and protein crystallization. However, even if MO has been extensively studied, simple isosteres of MO, while readily accessible, have seen limited characterization. An improved understanding of how relatively minor changes in lipid chemical structure affect self-assembly and membrane topology could instruct the construction of artificial cells and organelles for modeling biological structures and facilitate nanomaterial-based applications. Here, we investigate the differences in self-assembly and large-scale organization between MO and two MO lipid isosteres. We show that replacing the ester linkage between the hydrophilic headgroup and hydrophobic hydrocarbon chain with a thioesther or amide functional group results in the assembly of lipid structures with different phases not resembling those formed by MO. Using light and cryo-electron microscopy, small-angle X-ray scattering, and infrared spectroscopy, we demonstrate differences in the molecular ordering and large-scale architectures of the self-assembled structures made from MO and its isosteric analogues. These results improve our understanding of the molecular underpinnings of lipid mesophase assembly and may facilitate the development of MO-based materials for biomedicine and as model lipid compartments. |
