2-hydroxy fatty acid enantiomers of Gb3 impact shiga toxin binding and membrane organization
16.06.2015
Schütte OM, Patalag LJ, Weber LM, Ries A, Römer W, Werz DB, Steinem C.
Biophys J. 2015;108(12):2775-8.
Shiga toxin subunit B (STxB) binding to its cellular receptor Gb3 leads to the formation of protein-lipid clusters and bending of the membrane. A newly developed synthetic route allowed synthesizing the biologically most relevant Gb3-C24:1 2OH species with both, the natural (Gb3-R) as well as the unnatural (Gb3-S) configuration of the 2OH group. The derivatives bind STxB with identical nanomolar affinity, while the propensity to induce membrane tubules in giant unilamellar vesicles is more pronounced for Gb3-S. Fluorescence and atomic force microscopy images of phase-separated supported membranes revealed differences in the lateral organization of the protein on the membrane. Gb3-R favorably induces large and tightly packed protein clusters, while a lower protein density is found on Gb3-S doped membranes.
