Biomaterial Database

Filipin as a cholesterol probe. I. Morphology of filipin-cholesterol interaction in lipid model systems. 1984

O Beknke, and J Tranum-Jensen, and B van Deurs

We report some novel morphological observations on the interaction of the polyene antibiotic filipin (crude complex) with cholesterol, studied in non-cellular systems with replication, freeze-fracture, and negative stain techniques. Cholesterol crystals, lecithin liposomes containing 0 to 20 mole% of cholesterol, and liposomes containing 10 mole% of cholesterol and 5 to 40 mole% of sphingomyelin were incubated for varying lengths of time with filipin at different cholesterol: filipin molar ratios. The resulting filipin-induced lesions (FIL) were pleomorphic in all systems studied. In replicas of crystals, FIL appeared as ridges which were either straight, or curved into C- and S-shaped figures or closed circles. Negatively stained preparations showed FIL as white lines of the same configurations and in addition revealed a delicate veil attached to individual FIL. FIL, fused by their veils into clusters or large sheets ("holey sheets"), were shed from crystals. Incubation of liposomes for 1 h at cholesterol:filipin molar ratios of 4:1, 2:1, 1:1, and 1:5, demonstrated that cholesterol detection (i.e. formation of FIL) depend upon the ratio of cholesterol to filipin. At a 1:1 molar ratio FIL formed on liposomes containing 10 mole% cholesterol or more, but detectability increased to 5 mole% at the 1:5 ratio. Increasing the molar ratio of cholesterol:filipin to 2:1 and 4:1 decreased cholesterol detectability to between 10 and 20 mole%. Increasing concentrations of sphingomyelin decreased cholesterol detectability at the 1:1 cholesterol:filipin ratio; further, FIL in sphingomyelin-containing liposomes tended towards larger diameters. Filipin induced aggregation of liposomes and linked them together by holey sheets, providing evidence for filipin-induced extraction of cholesterol from liposomes. Taken together our morphological observations on filipin-cholesterol interaction in non-cellular systems raise pertinent questions as to the feasibility of filipin as a cholesterol probe in cellular systems.

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
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
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
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
D011090	Polyenes	Hydrocarbons with more than one double bond. They are a reduced form of POLYYNES.	Cumulenes
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
D003461	Crystallography	The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystallographies
D005372	Filipin	A complex of polyene antibiotics obtained from Streptomyces filipinensis. Filipin III alters membrane function by interfering with membrane sterols, inhibits mitochondrial respiration, and is proposed as an antifungal agent. Filipins I, II, and IV are less important.	Filipin III,Desoxylagosin,Filimarisin,Filipin I,Filipin II,Filipin IV,NSC-3364,U-5956,NSC 3364,NSC3364,U 5956,U5956
D013109	Sphingomyelins	A class of sphingolipids found largely in the brain and other nervous tissue. They contain phosphocholine or phosphoethanolamine as their polar head group so therefore are the only sphingolipids classified as PHOSPHOLIPIDS.	Sphingomyelin