title: Biophysical characterization of a new phospholipid analogue with a spin-labeled unsaturated fatty acyl chain.
abstract: Spin-labeled analogs of phospholipids have been used widely to characterize the biophysical properties of membranes. We describe synthesis and application of a new spin-labeled phospholipid analog, SL-POPC. The advantage of this molecule is that the EPR active doxyl group is linked to an unsaturated fatty acyl chain different to saturated phospholipid analogs used so far. The need for those analogs arises from the fact that biological membranes contain unsaturated phospholipids to a large extent. The biophysical properties of SL-POPC in membranes were characterized using EPR and NMR spectroscopy and compared with those of the saturated spin-labeled phospholipid, SL-PSPC. To this end, POPC membranes were labeled with either analog to assess whether the spin-labeled counterpart SL-POPC mimics the membrane properties better than the often used SL-PSPC. The results show that SL-POPC and SL-PSPC explore different molecular environments of the bilayer, and that the type and degree of perturbation of bilayer caused by the label moiety also differs between both analogs. We found that SL-POPC is more appropriate to assess the versatile dynamics of POPC membranes than SL-PSPC.
authors.affiliation: Institute of Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bunge
authors.forename: Anne-Katrin
authors.initials: AK
authors.lastname: Windeck
authors.forename: Thomas
authors.initials: T
authors.lastname: Pomorski
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schiller
authors.forename: Andreas
authors.initials: A
authors.lastname: Herrmann
authors.forename: Daniel
authors.initials: D
authors.lastname: Huster
authors.forename: Peter
authors.initials: P
authors.lastname: Müller
mesh_terms: D055592:Biophysical Phenomena; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D005227:Fatty Acids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010713:Phosphatidylcholines / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D013113:Spin Labels
chemical_list: D005227:Fatty Acids; D010713:Phosphatidylcholines; D013113:Spin Labels; C028694:1-palmitoyl-2-oleoylphosphatidylcholine