Specificity of phosphatidylserine-containing membrane binding sites for factor VIII. Studies with model membranes supported by glass microspheres (lipospheres). 1992

G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
Department of Medicine, Brockton-West Roxbury Veterans Administration Medical Center, West Roxbury, Massachusetts 02132.

Factor VIII functions in an enzyme complex upon the activated platelet membrane where phosphatidylserine exposure correlates with expression of receptors for factor VIII. To evaluate the specificity of phosphatidylserine-containing membrane binding sites for factor VIII, we have developed a novel membrane model in which phospholipid bilayers are supported by glass microspheres (lipospheres). The binding of fluorescein-labeled factor VIII to lipospheres with membranes of 15% phosphatidylserine was equivalent to binding to phospholipid vesicles (KD = 4.8 nM). Purified von Willebrand factor (vWf), a carrier protein for factor VIII, decreased membrane binding of factor VIII with a Ki of 10 micrograms/ml. Likewise, normal plasma decreased bound factor VIII by more than 90% whereas plasma lacking vWf decreased the binding of factor VIII by only 20%. Proteolytic activation of factor VIII by thrombin, which releases factor VIII from vWf, increased liposphere binding in the presence of vWf and in the presence of normal plasma. Although factor V is homologous to factor VIII and binds to lipospheres with the same affinity, purified factor V was not an efficient competitor for the membrane binding sites of factor VIII. These results indicate that phosphatidylserine-containing membrane sites have sufficient specificity to select thrombin-activated factor VIII from the range of phospholipid-binding proteins in plasma.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008027 Light That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range. Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
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
D008433 Mathematics The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Mathematic
D008563 Membrane Lipids Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation. Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D008856 Microscopy, Fluorescence Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye. Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D008863 Microspheres Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers. Latex Beads,Latex Particles,Latex Spheres,Microbeads,Bead, Latex,Beads, Latex,Latex Bead,Latex Particle,Latex Sphere,Microbead,Microsphere,Particle, Latex,Particles, Latex,Sphere, Latex,Spheres, Latex
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
D005165 Factor V Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor V accomplishes this by forming a complex with factor Xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor V leads to Owren's disease. Coagulation Factor V,Proaccelerin,AC Globulin,Blood Coagulation Factor V,Factor 5,Factor Five,Factor Pi,Factor V, Coagulation

Related Publications

G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
October 2003, Biochimica et biophysica acta,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
September 2015, Blood,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
October 2009, Biophysical journal,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
August 1995, The Journal of biological chemistry,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
January 2022, Frontiers in molecular biosciences,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
October 2022, ACS applied materials & interfaces,
G E Gilbert, and D Drinkwater, and S Barter, and S B Clouse
September 1998, Biochemistry,
Copied contents to your clipboard!