- Tytuł:
- The Effect of Mild Rehydration on Freeze-Dried Dipalmitoylphosphatidylcholine (DPPC) Multilamellar Membranes as Observed by Proton NMR and Sorption Isotherm
- Autorzy:
-
Harańczyk, H.
Leja, A.
Nowak, P.
Baran, E.
Strzałka, K. - Powiązania:
- https://bibliotekanauki.pl/articles/1398809.pdf
- Data publikacji:
- 2016-02
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
82.56.Na
87.16.D- - Opis:
- Between neighbouring bilayers of lyophilized dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles the total number of water molecules equals 9 H₂O molecules/1 DPPC molecule. One of these molecules is very tightly bound to the lipid molecule, seven are in immobilized (tightly bound) water fraction whereas the last one belongs to mobile water fraction. The rehydration from the gaseous phase of the DPPC model membranes was investigated using hydration kinetics, sorption isotherm, and high power proton relaxometry. The obtained data for DPPC were compared with these obtained for wheat photosynthetic membranes. Rehydrated photosynthetic membranes differ from DPPC model membranes in hydration kinetics. The average hydration time has a similar value: (22.0 ± 2.8) h (photosynthetic membrane) and (19.8 ± 1.6) h (DPPC), however hydration kinetics was described by one-exponential function for photosynthetic membrane, while for model membrane it shows fine double exponential form. The sigmoidal form of sorption isotherm is better fitted using Dent model than by the Brunauer-Emmett-Teller formula. The Brunauer-Emmett-Teller/Dent deviation parameter b =0.93 either for photosynthetic or for model membranes. The mass of water saturating primary water binding sites equals ΔM/m₀= 0.017 (wheat photosynthetic membranes) and 0.027 (DPPC). The detected by NMR-isotherm study mass of water "sealed" in model membrane structures was about ΔMₛ/m₀=0.182 (about 7-8 H₂O molecules/1 DPPC molecule), and ΔMₛ/m₀= 0.066 for photosynthetic membrane.
- Źródło:
-
Acta Physica Polonica A; 2016, 129, 2; 179-184
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł