Biomaterial Database

Characterization of calcium-dependent binding of endogenous factor VIII/von Willebrand factor to surface activated platelets. 1984

F H Furby, and M C Berndt, and P A Castaldi, and J Koutts

Activation of washed platelets in the presence of EDTA with either 1 U/ml of alpha-thrombin or 2 microM calcium ionophore (A23187) caused the release of one-third to one-half of the platelet factor VIII/von Willebrand factor (FVIII/vWF) into the supernatant. When calcium was present in excess, only 10% of the platelet FVIII/vWF was detected free in the supernatant, regardless of whether calcium was present before stimulation or added to the platelets after thrombin activation. Release of [14C]serotonin and beta-thromboglobulin were not affected by divalent cations indicating that reduced supernatant levels of FVIII/vWF in the presence of calcium were not due to differential release, but were probably due to a calcium-dependent association of released FVIII/vWF with the platelet surface. The presence or absence of intact glycoprotein Ib on the platelet surface made no significant difference to the observed FVIII/vWF partition. Platelets from a patient with Glanzmann's thrombasthenia, however, failed to show a calcium effect with respect to released FVIII/vWF. The combined results suggest that as well as the ristocetin-dependent, divalent cation-independent binding of FVIII/vWF to glycoprotein Ib, there is a divalent cation-dependent binding of FVIII/vWF to the activated platelet surface which is mediated via the glycoprotein IIb/IIIa complex.

UI	MeSH Term	Description	Entries
D001779	Blood Coagulation Factors	Endogenous substances, usually proteins, that are involved in the blood coagulation process.	Clotting Factor,Coagulation Factors,Blood Coagulation Factor,Clotting Factors,Coagulation Factor,Coagulation Factor, Blood,Coagulation Factors, Blood,Factor, Coagulation,Factors, Coagulation,Factor, Blood Coagulation,Factor, Clotting,Factors, Blood Coagulation,Factors, Clotting
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
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
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005169	Factor VIII	Factor VIII of blood coagulation. Antihemophilic factor that is part of the factor VIII/von Willebrand factor complex. Factor VIII is produced in the liver and acts in the intrinsic pathway of blood coagulation. It serves as a cofactor in factor X activation and this action is markedly enhanced by small amounts of thrombin.	Coagulation Factor VIII,Factor VIII Clotting Antigen,Factor VIII Coagulant Antigen,Factor VIII Procoagulant Activity,Thromboplastinogen,Blood Coagulation Factor VIII,F VIII-C,Factor 8,Factor 8 C,Factor Eight,Factor VIIIC,Hyate-C,Hyatt-C,F VIII C,Hyate C,HyateC,Hyatt C,HyattC
D006023	Glycoproteins	Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.	C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000001	Calcimycin	An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.	4-Benzoxazolecarboxylic acid, 5-(methylamino)-2-((3,9,11-trimethyl-8-(1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl)-1,7-dioxaspiro(5.5)undec-2-yl)methyl)-, (6S-(6alpha(2S,3S),8beta(R*),9beta,11alpha))-,A-23187,A23187,Antibiotic A23187,A 23187,A23187, Antibiotic
D013917	Thrombin	An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.	Thrombase,Thrombin JMI,Thrombin-JMI,Thrombinar,Thrombostat,alpha-Thrombin,beta,gamma-Thrombin,beta-Thrombin,gamma-Thrombin,JMI, Thrombin
D014841	von Willebrand Factor	A high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor VIII/von Willebrand factor complex. The von Willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. It functions in adhesion of platelets to collagen and hemostatic plug formation. The prolonged bleeding time in VON WILLEBRAND DISEASES is due to the deficiency of this factor.	Factor VIII-Related Antigen,Factor VIIIR-Ag,Factor VIIIR-RCo,Plasma Factor VIII Complex,Ristocetin Cofactor,Ristocetin-Willebrand Factor,von Willebrand Protein,Factor VIII Related Antigen,Factor VIIIR Ag,Factor VIIIR RCo,Ristocetin Willebrand Factor