Phospholipid lateral diffusion in phosphatidylcholine-sphingomyelin-cholesterol monolayers; Effects of oxidatively truncated phosphatidylcholines

0434363 - ÚFCH JH 2016 RIV NL eng J - Journal Article
Parkkila, P. - Štefl, Martin - Olžyńska, Agnieszka - Hof, Martin - Kinnunen, P. K. J.
Phospholipid lateral diffusion in phosphatidylcholine-sphingomyelin-cholesterol monolayers; Effects of oxidatively truncated phosphatidylcholines.
Biochimica Et Biophysica Acta-Biomembranes. Roč. 1848, č. 1 (2015), s. 167-173. ISSN 0005-2736. E-ISSN 1879-2642
R&D Projects: GA ČR GBP208/12/G016
Institutional support: RVO:61388955
Keywords : Oxidatively truncated phosphatidylcholines * Lateral diffusion * Fluorescence correlation spectroscopy
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.687, year: 2015

Oxidative stress is involved in a number of pathological conditions and the generated oxidatively modified lipids influence membrane properties and functions, including lipid–protein interactions and cellular signaling. Brewster angle microscopy demonstrated oxidatively truncated phosphatidylcholines to promote phase separation in monolayers of 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (POPC), sphingomyelin (SM) and cholesterol (Chol). More specifically, 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), was found to increase the miscibility transition pressure of the SM/Chol-phase. Lateral diffusion of lipids is influenced by a variety of membrane properties, thus making it a sensitive parameter to observe the coexistence of different lipid phases, for instance. The dependence on lipid lateral packing of the lateral diffusion of fluorophore-containing phospholipid analogs was investigated in Langmuir monolayers composed of POPC, SM, and Chol and additionally containing oxidatively truncated phosphatidylcholines, using fluorescence correlation spectroscopy (FCS). To our knowledge, these are the first FCS results on miscibility transition in ternary lipid monolayers, confirming previous results obtained using Brewster angle microscopy on such lipid monolayers. Wide-field fluorescence microscopy was additionally employed to verify the transition, i.e. the loss and reformation of SM/Chol domains.
Permanent Link: http://hdl.handle.net/11104/0238434