Biomaterial Database

A mechanism of divalent ion-induced phosphatidylserine membrane fusion. 1982

S Ohki

A mechanism for the divalent cation-induced membrane fusion of phosphatidylserine membranes is proposed. Fusion was followed by the Tb/DPA (dipicolinic acid) assay, monitoring the fluorescent intensity for mixing of the internal aqueous contents of unilamellar lipid vesicles, and the threshold concentrations required for various divalent cations to induce membrane fusion were determined from the fluorescence spectrum of the lipid vesicle suspension with respect to various concentrations of divalent ions. Also, the surface tension of monolayers made of the same lipids as used in the fusion experiments was measured with respect to the variation of divalent cation concentrations. The surface tension increase in the monolayer, induced by changing divalent ion concentrations from zero to a concentration which corresponded to its threshold concentration to induce vesicle membrane fusion, was the same (approx. 8 dyn/cm) for all divalent ions used. From these experimental data and theory concerning ion binding to the membrane, it is deduced that the main cause of divalent cation-induced membrane fusion of phosphatidylserine membranes is the degree of increased hydrophobicity (surface tension increase) of the membrane surface, which results from the binding of cations to acidic phospholipid membrane surfaces. Some discussion on the molecular mechanism of phospholipid membrane fusion is given.

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
D010718	Phosphatidylserines	Derivatives of PHOSPHATIDIC ACIDS in which the phosphoric acid is bound in ester linkage to a SERINE moiety.	Serine Phosphoglycerides,Phosphatidyl Serine,Phosphatidyl Serines,Phosphatidylserine,Phosphoglycerides, Serine,Serine, Phosphatidyl,Serines, Phosphatidyl
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D002459	Cell Fusion	Fusion of somatic cells in vitro or in vivo, which results in somatic cell hybridization.	Cell Fusions,Fusion, Cell,Fusions, Cell
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D013500	Surface Tension	The force acting on the surface of a liquid, tending to minimize the area of the surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Interfacial Force,Interfacial Tension,Surface Tensions,Tension, Surface,Tensions, Surface