scholarly journals Complex formation of platelet membrane glycoproteins IIb and IIIa with fibrinogen.

1982 ◽  
Vol 69 (2) ◽  
pp. 263-269 ◽  
Author(s):  
R L Nachman ◽  
L L Leung
1984 ◽  
Vol 259 (13) ◽  
pp. 8584-8588 ◽  
Author(s):  
R L Nachman ◽  
L L Leung ◽  
M Kloczewiak ◽  
J Hawiger

1981 ◽  
Author(s):  
R Nachman ◽  
L Leung

Platelet membrane glycoproteins IIb and IIIa were isolated and purified from human platelet membranes using lentil lectin affinity chromatography and electrophoretic elution from SDS-poly-acrylamide gels. Two dimensional immunoelectrophoresis of a mixture of the purified proteins against monospecific antisera showed antigenic uniqueness of the separate polypeptides. Computerized analysis of autoradiographs of two dimensional tryptic 125I peptide maps revealed that the two glycoproteins had completely different structures. Thus human platelet membrane glycoproteins IIb and IIIa are separate molecular entities. Monospecific anti-GPIIb and anti-GPIIIa were utilized in an enzyme linked immunosorbent assay system to demonstrate complex formation of the platelet glycoproteins with purified human fibrinogen. The formation of this GPIIb-GPIIIa fibrinogen complex is calcium dependent, fibrinogen specific, saturable, and inhibited by specific amino sugars and amino acids. These observations suggest that the GPIIb-GPIIIa macromolecular complex on the platelet surface acts under the proper physiologic circumstances as the fibrinogen binding site required for normal platelet aggregation.


1998 ◽  
Vol 79 (04) ◽  
pp. 832-836 ◽  
Author(s):  
Thomas Fischer ◽  
Christina Duffy ◽  
Gilbert White

SummaryPlatelet membrane glycoproteins (GP) IIb/IIIa and rap1b, a 21 kDa GTP binding protein, associate with the triton-insoluble, activation-dependent platelet cytoskeleton with similar rates and divalent cation requirement. To examine the possibility that GPIIb/IIIa was required for rap1b association with the cytoskeleton, experiments were performed to determine if the two proteins were linked under various conditions. Chromatography of lysates from resting platelets on Sephacryl S-300 showed that GPIIb/IIIa and rap1b were well separated and distinct proteins. Immunoprecipitation of GPIIb/IIIa from lysates of resting platelets did not produce rap1b or other low molecular weight GTP binding proteins and immunoprecipitation of rap1b from lysates of resting platelets did not produce GPIIb/IIIa. Finally, rap1b was associated with the activation-dependent cytoskeleton of platelets from a patient with Glanzmann’s thrombasthenia who lacks surface expressed glycoproteins IIb and IIIa. Based on these findings, we conclude that no association between GPIIb/IIIa and rap1b is found in resting platelets and that rap1b association with the activation-dependent cytoskeleton is at least partly independent of GPIIb/IIIa.


1996 ◽  
Vol 16 (02) ◽  
pp. 114-138 ◽  
Author(s):  
R. E. Scharf

SummarySpecific membrane glycoproteins (GP) expressed by the megakaryocyte-platelet system, including GPIa-lla, GPIb-V-IX, GPIIb-llla, and GPIV are involved in mediat-ing platelet adhesion to the subendothelial matrix. Among these glycoproteins, GPIIb-llla plays a pivotal role since platelet aggregation is exclusively mediated by this receptor and its interaction with soluble macromolecular proteins. Inherited defects of the GPIIb-llla or GPIb-V-IX receptor complexes are associated with bleeding disorders, known as Glanzmann's thrombasthenia, Bernard-Soulier syndrome, or platelet-type von Willebrand's disease, respectively. Using immuno-chemical and molecular biology techniques, rapid advances in our understanding of the molecular genetic basis of these disorders have been made during the last few years. Moreover, analyses of patients with congenital platelet membrane glycoprotein abnormalities have provided valuable insights into molecular mechanisms that are required for structural and functional integrity, normal biosynthesis of the glycoprotein complexes and coordinated membrane expression of their constituents. The present article reviews the current state of knowledge of the major membrane glycoproteins in health and disease. The spectrum of clinical bleeding manifestations and established diagnostic criteria for each of these dis-orders are summarized. In particular, the variety of molecular defects that have been identified so far and their genetic basis will be discussed.


1979 ◽  
Vol 42 (05) ◽  
pp. 1490-1502 ◽  
Author(s):  
C S P Jenkins ◽  
E F Ali-Briggs ◽  
G T E Zonneveld ◽  
A Sturk ◽  
J Clemetson

SummaryThe separation of the major platelet membrane glycoproteins of normal subjects and subjects with well defined platelet membrane glycoprotein abnormalities have been examined using four different polyacrylamide gel electrophoretic techniques (continuous and discontinuous). The mobilities of the resolved glycoprotein bands have been correlated with the glycoprotein nomenclature proposed for the conventional sodium dodecyl sulphate- phosphate buffer system. Since the glycoprotein distribution varies depending on the system used, the merits of each method should be considered before application to a specific problem.


1987 ◽  
Vol 516 (1 Blood in Cont) ◽  
pp. 52-65 ◽  
Author(s):  
KJELL S. SAKARIASSEN ◽  
EDITH FRESSINAUD ◽  
JEAN-PIERRE GIRMA ◽  
DOMINIQUE MEYER ◽  
HANS R. BAUMGARTNER

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