Conformational changes of lipids in bilayers at the dynamical transition near 200 K seen by Raman scattering.
Dynamical transition in biomolecules (proteins, membranes, etc.) is the phenomenon of increase of mean square atomic displacements, when temperature increases above 180-230 K. This increase is seen in neutron scattering and is ascribed to the increase of anharmonical motion of hydrogen atoms in biomolecules. In this work, Raman scattering study was performed for model synthetic membranes of dipalmitoylphosphatidylcholine in the spectral range of C-C vibrations (1050-1150 cm(-1)). It was demonstrated that dynamical transition is accompanied by appearance of newly achievable conformations of the lipid tails. In particular, the portion of the all-trans conformations decreases above the temperature of the dynamical transition. The data are compared with simple theoretical models.
Surovtsev
N V
NV
Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, 630090, Russia. lab21@iae.nsk.su
Dzuba
S A
SA
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008958:Models, Molecular; D009502:Neutrons; D013059:Spectrum Analysis, Raman; D013696:Temperature; D014732:Vibration
D008051:Lipid Bilayers; D015060:1,2-Dipalmitoylphosphatidylcholine