Lipid interactions of the human G-protein-coupled receptor chemokine receptor CXCR1 in asymmetric vesicles
Final Report Abstract
The asymmetric distribution of lipids between the two bilayer leaflets represents a typical feature of biological membranes. The loss of this asymmetry, for example the exposure of negatively charged lipids on the extracellular membrane leaflet of mammalian cells, is involved in apoptosis and occurs in tumor cells. Thus, the controlled production of asymmetric liposomes helps to better understand such crucial cellular processes. Here, we present an approach that allows us to design asymmetric model-membrane experiments on a rational basis and predict the fraction of exchanged lipid. In addition, we developed a label-free and nondestructive assay to quantify the asymmetric uptake of negatively charged lipids in terms of the zeta potential. This significantly enhances the applicability, impact, and predictive power of model membranes. For the G-protein coupled receptor CXCR1, we developed a nanodisc-based platform that allows for the biophysical characterization of lipid effects on the structure and function of the receptor. Taken together, this work expands the toolbox of membrane-protein biophysics and has been received enthusiastically at presentations in Europe and North America.
Publications
- (2018) Preparation of Asymmetric Liposomes Using a Phosphatidylserine Decarboxylase. Biophysical journal 115 (8) 1509–1517
Drechsler, Carina; Markones, Marie; Choi, Jae-Yeon; Frieling, Niklas; Fiedler, Sebastian; Voelker, Dennis R.; Schubert, Rolf; Heerklotz, Heiko
(See online at https://doi.org/10.1016/j.bpj.2018.08.036) - Vesicle Leakage Reflects the Target Selectivity of Antimicrobial Lipopeptides from Bacillus subtilis. Biophysical Journal (2015), 109, 2079–2089
Fiedler S., Heerklotz H.
(See online at https://doi.org/10.1016/j.bpj.2015.09.021) - Engineering Asymmetric Lipid Vesicles: Accurate and Convenient Control of the Outer Leaflet Lipid Composition. Langmuir (2018), 34, 1999–2005
Markones M., Drechsler C., Kaiser M., Kalie L., Heerklotz H., Fiedler S.
(See online at https://doi.org/10.1021/acs.langmuir.7b03189)
