Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Structural and morphological investigations of the formation of quasi-crystalline phases of 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG)
Autore:
Garidel, P; Richter, W; Rapp, G; Blume, A;
Indirizzi:
Univ Halle Wittenberg, Inst Phys Chem, D-06108 Halle, Germany Univ Halle Wittenberg Halle Germany D-06108 Chem, D-06108 Halle, Germany Rutgers State Univ, Dept Chem, Newark, NJ 07102 USA Rutgers State Univ Newark NJ USA 07102 v, Dept Chem, Newark, NJ 07102 USA Univ Jena, Inst Ultrastruct Res, D-07740 Jena, Germany Univ Jena Jena Germany D-07740 st Ultrastruct Res, D-07740 Jena, Germany HASYLAB, MPI Colloid & Interface Sci, D-22603 Hamburg, Germany HASYLAB Hamburg Germany D-22603 Interface Sci, D-22603 Hamburg, Germany
Titolo Testata:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
fascicolo: 8, volume: 3, anno: 2001,
pagine: 1504 - 1513
SICI:
1463-9076(2001)3:8<1504:SAMIOT>2.0.ZU;2-H
Fonte:
ISI
Lingua:
ENG
Soggetto:
X-RAY-DIFFRACTION; CHARGED PHOSPHOLIPID 1,2-DIMYRISTOYL-SN-GLYCERO-3-PHOSPHOGLYCEROL; HYDRATED DIPALMITOYLPHOSPHATIDYLCHOLINE BILAYERS; LIPID-PEPTIDE INTERACTIONS; ALKALINE-EARTH CATIONS; THERMOTROPIC BEHAVIOR; PHOSPHATIDYLGLYCEROL MIXTURES; PHOSPHATIDYLSERINE BILAYERS; HYDROCARBON CHAINS; SUB-TRANSITION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
58
Recensione:
Indirizzi per estratti:
Indirizzo: Garidel, P Univ Halle Wittenberg, Inst Phys Chem, Muhlpforte 1, D-06108 Halle, Germany Univ Halle Wittenberg Muhlpforte 1 Halle Germany D-06108 rmany
Citazione:
P. Garidel et al., "Structural and morphological investigations of the formation of quasi-crystalline phases of 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG)", PHYS CHEM P, 3(8), 2001, pp. 1504-1513

Abstract

1,2-Dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) in 100 mM NaCl at pH 7forms a quasi-crystalline gel phase (L-c phase) when stored for several days or longer at 4 degreesC. We studied the structure and morphology of thisphase by freeze-fracture electron microscopy, synchrotron X-ray diffraction, and Fourier transform infrared spectroscopy (FTIR). The phase behavior was also followed by differential scanning calorimetry. Freeze-fracture electron microscopy revealed two different distinct morphological aggregates for the L-c phase, namely flat multilamellar sheets and cochleate cylinders in an approximately 1:1 ratio. FTIR investigations showed that the hydrocarbon chains are tightly packed within an orthorhombic subcell lattice. The frequency shift of the ester carbonyl bands to lower wavenumbers (1732 cm(-1)) indicates a direct involvement of the carbonyl groups in hydrogen bondingwith hydroxy groups. The freeze-fracture electron microscopic and X-ray investigation reveal very tightly packed lamellar aggregates. The small lamellar repeat distance of 4.75 nm indicates that only a thin water layer is present between the lipid bilayers. The set of reflections observed in the wide angle X-ray region resembles that of the crystalline L-c phase observed in phosphatidylcholines. Upon cooling, the lamellar repeat distance observed in the liquid-crystalline phase increases drastically until the transition into the lamellar gel phase occurs. Then, the reflection in the low angleregion becomes broad and diffuse. This finding agrees with the electron microscopic results that upon cooling multilamellar aggregates are destroyed and unilamellar DMPG vesicles are formed below the main phase transition. The unilamellar vesicles fuse to lamellar stacks upon low temperature storage and these then roll up into cochleate cylinders. The observed behavior isattributed to the unique properties of the glycerol headgroup in being able to replace water molecules in the hydration shell.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/01/21 alle ore 23:12:54