Biomaterial Database

Interaction of cholesterol with photoactivable phospholipids in sonicated vesicles. 1981

G E Gerber, and R Radhakrishhnan, and C M Gupta, and H G Khorana

Photoactivable phospholipids containing either alpha-diazo-beta-trifluoropropionyloxy or m-diazirinophenoxyl groups in the omega-positions of sn-2 fatty acyl chains were synthesized and incorporated into sonicated vesicles containing 33 mol% of cholesterol. Photolysis of the vesicles at 350 nm produced covalent cross-links between the synthetic phospholipids and cholesterol. The cross-linked products obtained using [14C]cholesterol were characterized by their chromatographic behavior, cleavage on phospholipase A2 treatment, base-catalyzed transesterification and mass spectral measurements. The cross-linking was shown not to involve the 3-beta-hydroxyl group of cholesterol, and it was concluded that the reactive carbene intermediates formed from the photolabels inserted into the hydrocarbon skeleton of cholesterol in the bilayer. The extent of cross-linking obtained was comparable to that observed previously using phospholipids alone, indicating that no lateral phase separation occurred. The present approach is promising for further precise studies of the molecular interactions between cholesterol and phospholipids in biological membranes.

UI	MeSH Term	Description	Entries
D008567	Membranes, Artificial	Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.	Artificial Membranes,Artificial Membrane,Membrane, Artificial
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
D010741	Phospholipases A	Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D010782	Photolysis	Chemical bond cleavage reactions resulting from absorption of radiant energy.	Photodegradation
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
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
D014465	Ultrasonics	A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.	Ultrasonic
D054467	Phospholipases A2	Phospholipases that hydrolyze the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.	Lecithinase A2,Phospholipase A2
D055598	Chemical Phenomena	The composition, structure, conformation, and properties of atoms and molecules, and their reaction and interaction processes.	Chemical Concepts,Chemical Processes,Physical Chemistry Concepts,Physical Chemistry Processes,Physicochemical Concepts,Physicochemical Phenomena,Physicochemical Processes,Chemical Phenomenon,Chemical Process,Physical Chemistry Phenomena,Physical Chemistry Process,Physicochemical Phenomenon,Physicochemical Process,Chemical Concept,Chemistry Process, Physical,Chemistry Processes, Physical,Concept, Chemical,Concept, Physical Chemistry,Concept, Physicochemical,Concepts, Chemical,Concepts, Physical Chemistry,Concepts, Physicochemical,Phenomena, Chemical,Phenomena, Physical Chemistry,Phenomena, Physicochemical,Phenomenon, Chemical,Phenomenon, Physicochemical,Physical Chemistry Concept,Physicochemical Concept,Process, Chemical,Process, Physical Chemistry,Process, Physicochemical,Processes, Chemical,Processes, Physical Chemistry,Processes, Physicochemical