Инд. авторы:	Surovtsev N.V., Dzuba S.A.
Заглавие:	Flexibility of phospholipids with saturated and unsaturated chains studied by Raman scattering: The effect of cholesterol on dynamical and phase transitions
Библ. ссылка:	Surovtsev N.V., Dzuba S.A. Flexibility of phospholipids with saturated and unsaturated chains studied by Raman scattering: The effect of cholesterol on dynamical and phase transitions // Journal of Chemical Physics. - 2014. - Vol.140. - Iss. 23. - Art.235103. - ISSN 0021-9606. - EISSN 1089-7690.
Внешние системы:	DOI: 10.1063/1.4883237; PubMed: 24952570; SCOPUS: 2-s2.0-84903198578; WoS: 000337886200057;
Реферат:	eng: Raman scattering spectra were obtained at 25-320 K for bilayers prepared from saturated 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC) and mono-unsaturated 1-palmitoyl-2-oleoyl-snglycero- 3-phosphocholine (POPC) phospholipids, with and without cholesterol. Raman intensities were measured at modes sensitive to lipid inter-chain interactions and/or intra-chain torsional motion (asymmetric CH2 stretching at 2880 cm(-1)) and to the conformational state of lipids (C-C stretching at 1130 cm(-1)). These intensities decreased with temperature, which could be ascribed to increased lipid flexibility. For cholesterol-free and cholesterol-containing DPPC bilayers, the decrease of Raman intensities observed above similar to 200 K could be related to the phenomenon of dynamical transition known for biological systems near these temperatures. For a cholesterol-free POPC bilayer, the decrease of intensity for the asymmetric CH2 stretching mode started at a lower temperature, above 100 K, while the addition of cholesterol shifted this starting temperature to a more normal similar to 200 K value. The low-temperature lipid flexibility in the case of POPC was related to the abundance of free-volume holes, which disappeared in presence of cholesterol. Near gel-fluid phase transitions, Raman intensities for cholesterol-free bilayers dropped sharply, while for cholesterol-containing bilayers, they changed smoothly. (C) 2014 AIP Publishing LLC.
Ключевые слова:	TEMPERATURE; CW EPR; GLASS-TRANSITION; BIOLOGICAL-MEMBRANES; MOLECULAR FLEXIBILITY; LIPID-BILAYERS; HYDRATION WATER; NEUTRON-SCATTERING; ECHO-DETECTED EPR; PROTEIN;
Издано:	2014
Физ. характеристика:	235103