Biomaterial Database

Outside-inside distributions and sizes of mixed phosphatidylcholine-cholesterol vesicles. 1976

B De Kruijff, and P R Cullis, and G K Radda

(1) The effect of the incorporation of cholesterol upon the distribution of various molecular species of phosphatidylcholine across the bilayers of mixed sonicated liposomes (vesicles) has been studied with 31P-MNR. (2) The outside-inside ratio of both saturated and unsaturated phosphatidylcholine species was not much affected by the incorporation of up to 30 mol% cholesterol. Above 30 mol% cholesterol the outside-inside ratio strongly increased for phosphatidylcholines with cis unsaturated fatty acid chains. In contrast the outside-inside ratio of trans unsaturated and fully saturated phophatidylcholine species was either not affected or decreased by the incorporation of more than 30 mol% cholesterol. (3) a simple relationship between the size of the vesicle and the linewidth of the 31P-NMR resonance is described. From the measured linewidths the sizes of the various cholesterol containing vesicles have been obtained. It is found that incorporation of 0-30 mol% cholesterol does not significantly affect the size of the vesicle whereas above 30 mol% cholesterol does not significantly affect the size of the vesicle whereas above 30 mol% cholesterol the size of all phosphatidylcholine vesicles sharply increases. The increase in size is the largest for the more saturated phosphatidylcholine species. (4) From the outside-inside ratio and the size of the vesicle the composition of the outer and inner layer of the mixed vesicles could be obtained. Below 30 mol% cholesterol the composition of outer and inner layer is nearly identical. Above 30 mol% cholesterol the distribution of lipid across the bilayer of all visicles becomes assymetric with a disporportionately larger amount of cholesterol present in the inside monolayer.

UI	MeSH Term	Description	Entries
D008081	Liposomes	Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.	Niosomes,Transferosomes,Ultradeformable Liposomes,Liposomes, Ultra-deformable,Liposome,Liposome, Ultra-deformable,Liposome, Ultradeformable,Liposomes, Ultra deformable,Liposomes, Ultradeformable,Niosome,Transferosome,Ultra-deformable Liposome,Ultra-deformable Liposomes,Ultradeformable Liposome
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D008968	Molecular Conformation	The characteristic three-dimensional shape of a molecule.	Molecular Configuration,3D Molecular Structure,Configuration, Molecular,Molecular Structure, Three Dimensional,Three Dimensional Molecular Structure,3D Molecular Structures,Configurations, Molecular,Conformation, Molecular,Conformations, Molecular,Molecular Configurations,Molecular Conformations,Molecular Structure, 3D,Molecular Structures, 3D,Structure, 3D Molecular,Structures, 3D Molecular
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D010713	Phosphatidylcholines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a CHOLINE moiety.	Choline Phosphoglycerides,Choline Glycerophospholipids,Phosphatidyl Choline,Phosphatidyl Cholines,Phosphatidylcholine,Choline, Phosphatidyl,Cholines, Phosphatidyl,Glycerophospholipids, Choline,Phosphoglycerides, Choline
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships