Phase behavior and lipid-membrane structure of phospholipid- glycosphingolipid liposomes and the thermal unfolding of insulin
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Phase behavior and lipid-membrane structure of phospholipid- glycosphingolipid liposomes and the thermal unfolding of insulin. / Pedersen, Tina B.; Frokjaer, Sven; Mouritsen, Ole G.; Jørgensen, Kent.
In: Journal of Liposome Research, Vol. 9, No. 2, 01.01.1999, p. 261-274.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Phase behavior and lipid-membrane structure of phospholipid- glycosphingolipid liposomes and the thermal unfolding of insulin
AU - Pedersen, Tina B.
AU - Frokjaer, Sven
AU - Mouritsen, Ole G.
AU - Jørgensen, Kent
PY - 1999/1/1
Y1 - 1999/1/1
N2 - The thermodynamic phase behavior and lipid-membrane structure of fully hydrated uni- and multilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) surface-modified by a glycosphingolipid, sulfogalactosylceramide (sulfatide), have been investigated by means of differential scanning calorimetry and fluorescence polarization spectroscopy. The calorimetric and spectroscopic scans of the two-component liposomes demonstrate a distinct influence of increasing amounts of sulfatide on the lipid-membrane thermodynamics. This is manifested as a broad gel-fluid phase-coexistence region and a low-temperature two- phase region composed of highly ordered lipids. In addition, the pre- transition is abolished for small concentrations of sulfatide. A well- defined heat capacity peak, reflecting a thermotropic chain melting transition is observed for liposomes composed of pure sulfatide. On basis of the calorimetric and spectroscopic data a phase diagram has been established in the full temperature and composition plane. Dynamic light scattering measurements of liposome sizes reveal that the incorporation of sulfatide into the DPPC membrane matrix leads to a stabilization of the characteristic size of the extruded liposomes. Furthermore, incubation with insulin does not affect the liposome size and the aggregational behavior of the two-component sulfatide-DPPC liposomes. In accordance with this, the heat capacity curves demonstrate an insignificant influence on both the lipid membrane phase behavior and the thermal unfolding characteristics of insulin.
AB - The thermodynamic phase behavior and lipid-membrane structure of fully hydrated uni- and multilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) surface-modified by a glycosphingolipid, sulfogalactosylceramide (sulfatide), have been investigated by means of differential scanning calorimetry and fluorescence polarization spectroscopy. The calorimetric and spectroscopic scans of the two-component liposomes demonstrate a distinct influence of increasing amounts of sulfatide on the lipid-membrane thermodynamics. This is manifested as a broad gel-fluid phase-coexistence region and a low-temperature two- phase region composed of highly ordered lipids. In addition, the pre- transition is abolished for small concentrations of sulfatide. A well- defined heat capacity peak, reflecting a thermotropic chain melting transition is observed for liposomes composed of pure sulfatide. On basis of the calorimetric and spectroscopic data a phase diagram has been established in the full temperature and composition plane. Dynamic light scattering measurements of liposome sizes reveal that the incorporation of sulfatide into the DPPC membrane matrix leads to a stabilization of the characteristic size of the extruded liposomes. Furthermore, incubation with insulin does not affect the liposome size and the aggregational behavior of the two-component sulfatide-DPPC liposomes. In accordance with this, the heat capacity curves demonstrate an insignificant influence on both the lipid membrane phase behavior and the thermal unfolding characteristics of insulin.
KW - Glycosphingolipid
KW - Insulin
KW - Phase behavior liposome stabilization
KW - Phospholipid
KW - Sulfatide
UR - http://www.scopus.com/inward/record.url?scp=0033003033&partnerID=8YFLogxK
U2 - 10.3109/08982109909024789
DO - 10.3109/08982109909024789
M3 - Journal article
AN - SCOPUS:0033003033
VL - 9
SP - 261
EP - 274
JO - Journal of Liposome Research
JF - Journal of Liposome Research
SN - 0898-2104
IS - 2
ER -
ID: 236895485