X-Ray Reflectometry of DMPS Monolayers on a Water Substrate
- Авторы: Tikhonov A.M.1, Asadchikov V.E.2, Volkov Y.O.2, Roshchin B.S.2, Ermakov Y.A.3
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Учреждения:
- Kapitza Institute for Physical Problems
- Shubnikov Institute of Crystallography, “Crystallography and Photonics” Federal Research Center
- Frumkin Institute of Physical Chemistry and Electrochemistry
- Выпуск: Том 125, № 6 (2017)
- Страницы: 1051-1057
- Раздел: Atoms, Molecules, Optics
- URL: https://journals.rcsi.science/1063-7761/article/view/191631
- DOI: https://doi.org/10.1134/S1063776117120093
- ID: 191631
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Аннотация
The molecular structure of dimyristoyl phosphatidylserine (DMPS) monolayers on a water substrate in different phase states has been investigated by X-ray reflectometry with a photon energy of ~8 keV. According to the experimental data, the transition from a two-dimensional expanded liquid state to a solid gel state (liquid crystal) accompanied by the ordering of the hydrocarbon tails C14H27 of the DMPS molecule occurs in the monolayer as the surface pressure rises. The monolayer thickness is 20 ± 3 and 28 ± 2 Å in the liquid and solid phases, respectively, with the deflection angle of the molecular tail axis from the normal to the surface in the gel phase being 26° ± 8°. At least a twofold decrease in the degree of hydration of the polar lipid groups also occurs under two-dimensional monolayer compression. The reflectometry data have been analyzed using two approaches: under the assumption about the presence of two layers with different electron densities in the monolayer and without any assumptions about the transverse surface structure. Both approaches demonstrate satisfactory agreement between themselves in describing the experimental results.
Об авторах
A. Tikhonov
Kapitza Institute for Physical Problems
Автор, ответственный за переписку.
Email: tikhonov@kapitza.ras.ru
Россия, ul. Kosygina 2, Moscow, 119334
V. Asadchikov
Shubnikov Institute of Crystallography, “Crystallography and Photonics” Federal Research Center
Email: tikhonov@kapitza.ras.ru
Россия, Leninskii pr. 59, Moscow, 119333
Yu. Volkov
Shubnikov Institute of Crystallography, “Crystallography and Photonics” Federal Research Center
Email: tikhonov@kapitza.ras.ru
Россия, Leninskii pr. 59, Moscow, 119333
B. Roshchin
Shubnikov Institute of Crystallography, “Crystallography and Photonics” Federal Research Center
Email: tikhonov@kapitza.ras.ru
Россия, Leninskii pr. 59, Moscow, 119333
Yu. Ermakov
Frumkin Institute of Physical Chemistry and Electrochemistry
Email: tikhonov@kapitza.ras.ru
Россия, Leninskii pr. 31, Moscow, 119071
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