Gb 3 Glycosphingolipids with Fluorescent Oligoene Fatty Acids: Synthesis and Phase Behavior in Model Membranes.

Autor: Patalag LJ; TU Braunschweig, Institut für Organische Chemie, Hagenring 30, 38106, Braunschweig, Germany., Sibold J; Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany., Schütte OM; Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany., Steinem C; Georg-August-Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstrasse 2, 37077, Göttingen, Germany., Werz DB; TU Braunschweig, Institut für Organische Chemie, Hagenring 30, 38106, Braunschweig, Germany.
Jazyk: angličtina
Zdroj: Chembiochem : a European journal of chemical biology [Chembiochem] 2017 Nov 02; Vol. 18 (21), pp. 2171-2178. Date of Electronic Publication: 2017 Sep 20.
DOI: 10.1002/cbic.201700414
Abstrakt: Glycosphingolipids are involved in a number of physiological and pathophysiological processes, and they serve as receptors for a variety of bacterial toxins and viruses. To investigate their function in lipid membranes, fluorescently labeled glycosphingolipids are highly desirable. Herein, a synthetic route to access Gb 3 glycosphingolipids with fluorescently labeled fatty acids, consisting of pentaene and hexaene moieties either at the terminus or in the middle of the acyl chain, has been developed. The fluorescent properties of the Gb 3 derivatives were investigated in small unilamellar vesicles composed of a raft-like mixture. Phase-separated giant unilamellar vesicles (GUVs) allowed the quantification of the apparent partitioning coefficients of the Gb 3 compounds by means of confocal fluorescence laser scanning microscopy. The determined partition coefficients demonstrate that the Gb 3 derivatives are preferentially localized in the liquid-disordered (l d ) phase. To analyze whether the compounds behave like their physiological counterparts, Cy3-labeled (Cy: cyanine) Shiga toxin B subunits (STxB) were specifically bound to Gb 3 -doped GUVs. However, the protein was favorably localized in the l d phase, in contrast to results reported for STxB bound to naturally occurring Gb 3 , which is discussed in terms of the packing density of the lipids in the liquid-ordered (l o ) phase.
(© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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