Molecular Analyses of the Platelet Glycoprotein Ib-IX-V Receptor

1998 ◽  
Vol 79 (03) ◽  
pp. 466-478 ◽  
Author(s):  
Jerry Ware
Keyword(s):  
Molecular Mechanisms ◽  
Thrombus Formation ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Ligand Interaction ◽  
Receptor Ligand ◽  
Wide Range ◽  
Ligand Interactions ◽  
Normal Hemostasis ◽  
Von Willebrand

IntroducationGlycoprotein receptors within the platelet membrane are essential for initiating platelet adhesion and aggregation on thrombogenic surfaces. As a response to vascular injury these receptors provide platelets with two essential properties i) the ability to bind adhesive substrates exposed at the site of injury (adhesion) and ii) the ability to recruit additional platelets to form a thrombus (aggregation). It is becoming increasingly evident that defined rheological conditions govern the physiological relevance of specific receptor-ligand interactions along with fundamentally distinct molecular mechanisms for individual receptors and their ligands. Among platelet receptors the glycoprotein (GP) Ib-IX-V complex is important because it initiates thrombus formation over a wide range of flow conditions through an initial interaction with the adhesive ligand, von Willebrand factor. The importance of this receptor-ligand interaction is best exemplified by congenital bleeding disorders resulting from the lack of either the receptor or the ligand, the Bernard-Soulier syndrome and von Willebrand disease, respectively. Additionally, the GP Ib component of the GP Ib-IX-V complex contains a binding site for α-thrombin and recent studies have strengthened the concept that the interaction between α-thrombin and GP Ib is of biological relevance. Unquestionably, studies dissecting the GP Ib-IX-V complex are defining essential aspects of normal hemostasis and thrombosis while providing key information on the molecular mechanisms governing the formation of pathologic platelet thrombi. This review will summarize recent advances in our understanding of the synthesis, structure and function of the platelet GP Ib-IX-V complex. Where possible, directions for future studies will be identified with an overall goal of achieving a more complete understanding on the role of the GP Ib-IX-V complex in platelet biology.

scholarly journals Visualizing the von Willebrand factor/glycoprotein Ib-IX axis with a platelet-type von Willebrand disease mutation

Blood ◽  
2009 ◽  
Vol 114 (27) ◽  
pp. 5541-5546 ◽  
Author(s):  
Jose A. Guerrero ◽  
Mark Kyei ◽  
Susan Russell ◽  
Junling Liu ◽  
T. Kent Gartner ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Thrombus Formation ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Glycoprotein Ib ◽  
Ligand Interaction ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractPlatelet-type von Willebrand disease (PT-VWD) is a bleeding disorder of the platelet glycoprotein Ib-IX/von Willebrand factor (VWF) axis caused by mutations in the glycoprotein Ib-IX receptor that lead to an increased affinity with VWF. In this report, platelets from a mouse expressing a mutation associated with PT-VWD have been visualized using state-of-the art image collection and processing. Confocal analysis revealed that VWF bound to the surface of single platelets and bridging micro-aggregates of platelets. Surface-bound VWF appears as a large, linear structure on the surface of 50% of the PT-VWD platelets. In vivo thrombus formation after chemical injury to the carotid artery revealed a severe impairment to occlusion as a consequence of the PT-VWD mutation. In vitro stimulation of PT-VWD platelets with adenosine diphosphate or thrombin demonstrates a significant block in their ability to bind fibrinogen. The impairment of in vivo thrombus formation and in vitro fibrinogen binding are more significant than might be expected from the observed platelet binding to VWF polymers over a small portion of the plasma membrane. Visualization of the receptor/ligand interaction and characterization of a severe antithrombotic phenotype provide a new understanding on the molecular basis of bleeding associated with the PT-VWD phenotype.

Alterations in the intrinsic properties of the GPIbα–VWF tether bond define the kinetics of the platelet-type von Willebrand disease mutation, Gly233Val

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Teresa A. Doggett ◽  
Gaurav Girdhar ◽  
Avril Lawshe ◽  
Jonathan L. Miller ◽  
Ian J. Laurenzi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Platelet Adhesion ◽  
Von Willebrand Disease ◽  
Intrinsic Properties ◽  
Receptor Ligand ◽  
Shear Rates ◽  
Mutant Receptor ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Platelet-type von Willebrand disease (PTVWD) is a bleeding disorder in which an increase of function mutation in glycoprotein Ibα (GPIbα), with respect to binding of von Willebrand factor (VWF), results in a loss of circulating high molecular weight VWF multimers together with a mild-moderate thrombocytopenia. To better ascertain the specific perturbations in adhesion associated with this disease state, we performed a detailed analysis of the kinetic and mechanical properties of tether bonds formed between PT-VWD platelets and the A1-domain of VWF. Results indicate that the GPIbα mutation, Gly233Val, promotes and stabilizes platelet adhesion to VWF at shear rates that do not support binding between the native receptor-ligand pair due to enhanced formation and increased longevity of the mutant tether bond (k0off values for mutant versus native complex of 0.67 ± 0.11 s-1 and 3.45 ± 0.37 s-1, respectively). By contrast, the sensitivity of this interaction to an applied force, a measure of bond strength, was similar to the wild-type (WT) receptor. Although the observed alterations in the intrinsic properties of the GPIbα–VWF tether bond are comparable to those reported for the type 2B VWD, distinct molecular mechanisms may be responsible for these function-enhancing bleeding disorders, as interactions between the mutant receptor and mutant ligand resulted in a greater stability in platelet adhesion. We speculate that the enhanced cellular on-rate together with the prolongation in the lifetime of the mutant receptor-ligand bond contributes to platelet aggregation in circulating blood by permitting the formation of multiple GPIbα–VWF-A1 interactions. (Blood. 2003;102:152-160)

Platelet Activation and Aggregation Induced by Recombinant von Willebrand Factors Reproducing Four Type 2B von Willebrand Disease Missense Mutations

1998 ◽  
Vol 79 (01) ◽  
pp. 211-216 ◽  
Author(s):  
Lysiane Hilbert ◽  
Claudine Mazurier ◽  
Christophe de Romeuf
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Missense Mutations ◽  
Inhibit Platelet Aggregation ◽  
Wild Type ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryType 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.

The Interaction of Botrocetin with Normal or Variant von Willebrand Factor (Types IIA and IIB) and Its Inhibition by Monoclonal Antibodies that Block Receptor Binding

1992 ◽  
Vol 68 (04) ◽  
pp. 464-469 ◽  
Author(s):  
Y Fujimura ◽  
S Miyata ◽  
S Nishida ◽  
S Miura ◽  
M Kaneda ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Von Willebrand Factor ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Normal Individuals ◽  
Rag 1 ◽  
The One ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca2+-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957–64).Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an “activated complex” formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GPIb, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.

scholarly journals Elucidating Binding Sites and Affinities of ERα Agonist and Antagonist to Human Alpha-Fetoprotein by in silico Modeling and Point Mutagenesis

2019 ◽  
Author(s):  
Nurbubu T. Moldogazieva ◽  
Daria S. Ostroverkhova ◽  
Nikolai N. Kuzmich ◽  
Vladimir V. Kadochnikov ◽  
Alexander A. Terentiev ◽  
...  
Keyword(s):  
Binding Sites ◽  
In Silico ◽  
Disulfide Bonds ◽  
Electrostatic Interactions ◽  
Molecular Mechanisms ◽  
3D Structure ◽  
Scoring Function ◽  
Alpha Fetoprotein ◽  
Ligand Interaction ◽  
Ligand Interactions

Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting variety of hydrophobic ligands including estrogens. AFP has been shown to inhibit estrogen receptor (ER)-positive tumor growth and this can be attributed to its estrogen-binding ability. Despite AFP has long been investigated, its three-dimensional (3D) structure has not been experimentally resolved and molecular mechanisms underlying AFP-ligand interaction remain obscure. In our study we constructed homology-based 3D model of human AFP (HAFP) with the purpose to perform docking of ERα ligands, three agonists (17β-estradiol, estrone and diethylstilbestrol) and three antagonists (tamoxifen, afimoxifene and endoxifen) into the obtained structure. Based on ligand docked scoring function, we identified three putative estrogen- and antiestrogen-binding sites with different ligand binding affinities. Two high-affinity sites were located in (i) a tunnel formed within HAFP subdomains IB and IIA and (ii) opposite side of the molecule in a groove originating from cavity formed between domains I and III, while (iii) the third low-affinity site was found at the bottom of the cavity. 100 ns MD simulation allowed studying their geometries and showed that HAFP-estrogen interactions occur due to van der Waals forces, while both hydrophobic and electrostatic interactions were almost equally involved in HAFP-antiestrogen binding. MM/GBSA rescoring method estimated binding free energies (ΔGbind) and showed that antiestrogens have higher affinities to HAFP as compared to estrogens. We performed in silico point substitutions of amino acid residues to confirm their roles in HAFP-ligand interactions and showed that Thr132, Leu138, His170, Phe172, Ser217, Gln221, His266, His316, Lys453, and Asp478 residues along two disulfide bonds, Cys224-Cys270 and Cys269-Cys277 have key roles in both HAFP-estrogen and HAFP-antiestrogen binding. Data obtained in our study contribute to understanding mechanisms underlying protein-ligand interactions and anti-cancer therapy strategies based on ER-binding ligands.

scholarly journals The von willebrand factor domain-mediating botrocetin-induced binding to glycoprotein IB lies between Val449 and Lys728

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 985-988 ◽  
Author(s):  
Y Fujimura ◽  
LZ Holland ◽  
ZM Ruggeri ◽  
TS Zimmerman
Keyword(s):  
Monoclonal Antibodies ◽  
Amino Acid ◽  
Von Willebrand Factor ◽  
Amino Acid Residue ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Tryptic Fragment ◽  
Alternative Agent ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Botrocetin, a component of Bothrops jararaca venom, induces von Willebrand factor (vWF)-dependent platelet agglutination and has been proposed as an alternative agent to ristocetin for evaluating vWF function. However, important differences between the vWF-platelet interactions induced by these two agents have suggested that different regions of vWF and the platelet may be involved in the interactions induced by the two agonists. We have recently demonstrated that binding of vWF to the platelet glycoprotein (GP) Ib receptor, either induced by ristocetin or as occurs spontaneously with asialo-vWF or vWF from IIb von Willebrand disease, is mediated by a domain residing on a 52/48- kilodalton (kD) tryptic fragment of vWF. This fragment extends from amino acid residue Val (449) to Lys (728). We have now found that this 52/48-kD fragment blocks botrocetin-induced binding of vWF to platelets and completely inhibits botrocetin-induced platelet agglutination. These results provide evidence that the vWF domain-mediating, botrocetin-induced platelet agglutination lies within the region delimited by this fragment and is therefore close to or identical with that which mediates ristocetin-induced binding and spontaneous binding of vWF to platelet GPIb. Anti-GPIb monoclonal antibodies also blocked agglutination, which showed that botrocetin, like ristocetin, induces binding of vWF to the GPIb receptor.

Regulation der primären Hämostase durch von-Willebrand-Faktor und ADAMTS13

2011 ◽  
Vol 31 (04) ◽  
pp. 275-280 ◽  
Author(s):  
U. Budde ◽  
R. Schneppenheim
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Coagulation Cascade ◽  
Platelet Glycoprotein ◽  
Platelet Adhesion And Aggregation ◽  
Hydrodynamic Shear ◽  
Specific Protease ◽  
Multiple Domains ◽  
Von Willebrand

SummaryVon Willebrand factor (VWF) is an adhesive, multi-functional huge multimerized protein with multiple domains harboring binding sites for collagen, platelet glycoprotein receptors and coagulation factor VIII (FVIII). The functional domains enable VWF to bind to the injured vessel wall, to recruit platelets to the site of injury by adhesion and aggregation and to bind and protect FVIII, an important cofactor of the coagulation cascade. VWF function in primary haemostasis is located in particular in the arterial and micro-circulation. This environment is exposed to high shear forces with hydrodynamic shear rates ranging over several orders of magnitude from 10–1 to 105 s-1 and requires particular mechanisms to enable platelet adhesion and aggregation under these variable conditions. The respective VWF function is strictly correlating with its multimer size. Lack or reduction of large VWF multimers is seen in patients with von Willebrand disease (VWD) type 2A which correlates with reduction of both VWF:platelet GPIb-binding and VWF:collagen binding and a bleeding phenotype. To prevent unlimited platelet adhesion and aggregation which is the cause of the microangiopathic disorder thrombotic thrombocytopenic purpura (TTP), VWF function is regulated by its specific protease ADAMTS13. Whereas a particular susceptibility of VWF to ADAMTS13 proteolysis is the cause of a frequent VWD type 2A phenotype, lack or dysfunction of ADAMTS13, either acquired by ADAMTS13 antibodies or by inherited ADAMTS13 deficiency (Upshaw-Schulman Syndrome), causes TTP. Therefore VWD and TTP represent the opposite manifestations of VWF related disorders, tightly linked to each other.

scholarly journals Low VWF: insights into pathogenesis, diagnosis, and clinical management

2020 ◽  
Vol 4 (13) ◽  
pp. 3191-3199 ◽  
Author(s):  
James S. O’Donnell
Keyword(s):  
Clinical Management ◽  
Molecular Mechanisms ◽  
Optimal Choice ◽  
Von Willebrand Disease ◽  
Limited Information ◽  
Von Willebrand ◽  
The Relationship ◽  
Willebrand Factor ◽  
Choice Of Therapy

Abstract von Willebrand disease (VWD) constitutes the most common inherited human bleeding disorder. Partial quantitative von Willebrand factor (VWF) deficiency is responsible for the majority of VWD cases. International guidelines recommend that patients with mild to moderate reductions in plasma VWF antigen (VWF:Ag) levels (typically in the range of 30-50 IU/dL) should be diagnosed with low VWF. Over the past decade, a series of large cohort studies have provided significant insights into the biological mechanisms involved in type 1 VWD (plasma VWF:Ag levels <30 IU/dL). In striking contrast, however, the pathogenesis underpinning low VWF has remained poorly understood. Consequently, low VWF patients continue to present significant clinical challenges with respect to genetic counseling, diagnosis, and management. For example, there is limited information regarding the relationship between plasma VWF:Ag levels and bleeding phenotype in subjects with low VWF. In addition, it is not clear whether patients with low VWF need treatment. For those patients with low VWF in whom treatment is deemed necessary, the optimal choice of therapy remains unknown. However, a number of recent studies have provided important novel insights into these clinical conundrums and the molecular mechanisms responsible for the reduced levels observed in low VWF patients. These emerging clinical and scientific findings are considered in this review, with particular focus on pathogenesis, diagnosis, and clinical management of low VWF.

The role of platelet von Willebrand factor in platelet adhesion and thrombus formation: a study of 34 patients with various subtypes of type I von Willebrand disease

1994 ◽  
Vol 86 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Edith Fressinaud ◽  
Augusto B. Federici ◽  
Giancarlo Castaman ◽  
Chantal Rothschild ◽  
Francesco Rodeghiero ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Von Willebrand Disease ◽  
Type I ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Elucidating Binding Sites and Affinities of ERα Agonists and Antagonists to Human Alpha-Fetoprotein by In Silico Modeling and Point Mutagenesis

2020 ◽  
Vol 21 (3) ◽  
pp. 893 ◽  
Author(s):  
Nurbubu T. Moldogazieva ◽  
Daria S. Ostroverkhova ◽  
Nikolai N. Kuzmich ◽  
Vladimir V. Kadochnikov ◽  
Alexander A. Terentiev ◽  
...  
Keyword(s):  
Binding Sites ◽  
In Silico ◽  
Electrostatic Interactions ◽  
Molecular Mechanisms ◽  
3D Structure ◽  
Alpha Fetoprotein ◽  
Affinity Binding ◽  
Scoring Functions ◽  
Ligand Interaction ◽  
Ligand Interactions

Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting a variety of hydrophobic ligands, including estrogens. AFP has been shown to inhibit estrogen receptor (ER)-positive tumor growth, which can be attributed to its estrogen-binding ability. Despite AFP having long been investigated, its three-dimensional (3D) structure has not been experimentally resolved and molecular mechanisms underlying AFP–ligand interaction remains obscure. In our study, we constructed a homology-based 3D model of human AFP (HAFP) with the purpose of molecular docking of ERα ligands, three agonists (17β-estradiol, estrone and diethylstilbestrol), and three antagonists (tamoxifen, afimoxifene and endoxifen) into the obtained structure. Based on the ligand-docked scoring functions, we identified three putative estrogen- and antiestrogen-binding sites with different ligand binding affinities. Two high-affinity binding sites were located (i) in a tunnel formed within HAFP subdomains IB and IIA and (ii) on the opposite side of the molecule in a groove originating from a cavity formed between domains I and III, while (iii) the third low-affinity binding site was found at the bottom of the cavity. Here, 100 ns molecular dynamics (MD) simulation allowed us to study their geometries and showed that HAFP–estrogen interactions were caused by van der Waals forces, while both hydrophobic and electrostatic interactions were almost equally involved in HAFP–antiestrogen binding. Molecular mechanics/Generalized Born surface area (MM/GBSA) rescoring method exploited for estimation of binding free energies (ΔGbind) showed that antiestrogens have higher affinities to HAFP as compared to estrogens. We performed in silico point substitutions of amino acid residues to confirm their roles in HAFP–ligand interactions and showed that Thr132, Leu138, His170, Phe172, Ser217, Gln221, His266, His316, Lys453, and Asp478 residues, along with two disulfide bonds (Cys224–Cys270 and Cys269–Cys277), have key roles in both HAFP–estrogen and HAFP–antiestrogen binding. Data obtained in our study contribute to understanding mechanisms underlying protein–ligand interactions and anticancer therapy strategies based on ERα-binding ligands.

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