title: Effects of newcastle disease virus glycoproteins on the structural and thermal behaviour of 1,2-dihexadecyl-sn-glycero-3-phosphatidylcholine lipid membranes under osmotic stress conditions.
abstract: The interaction of hem agglutininneuraminidase (HN) and fusion (F) glycoproteins with swollen vesicles of 1,2-dihexadecyl-sn-glycero-3-phosphatidylcholine (DHPC) was investigated under transition from gel to fluid phase. X-ray studies of the structure of lipid/HN-F mixtures in normal and swollen vesicles have shown that the lamellar bilayer structure predominate in the gel and liquid crystalline phases. A swollen lipid phase, in which the mean repeat distance of lipid bilayers is larger than in the other phases was found. The nature of this phase is similar to the anomalous bilayer swelling reported in literature. The presence of HN and F in the vesicles led to the coexistence of structures with low and high lamellar order, showing larger repeat distance in comparison with the pure lipid. This finding was attributed to the increase in the lipid bilayer thickness due to the HN-F included in the free water layer. The thermal behaviour of the system was not affected by the vesicle swelling. The data showed the existence of gel and liquid crystalline lamellar phases and changes in lipid/HN-F specific heats, mainly due to the concentration effect of the HN-F and its location in the free water layer.
authors.affiliation: Institute of Geology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
authors.forename: Rita
authors.initials: R
authors.lastname: Pravchanska
authors.forename: Petrana
authors.initials: P
authors.lastname: Borissova
authors.forename: Lyubka
authors.initials: L
authors.lastname: Doumanova
authors.forename: Vassil
authors.initials: V
authors.lastname: Neitchev
authors.forename: Peter
authors.initials: P
authors.lastname: Laggner
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D009997:Osmotic Pressure; D010713:Phosphatidylcholines / Q000737:chemistry*; D014760:Viral Fusion Proteins / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D014760:Viral Fusion Proteins