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A highly conserved sequence of the Arg-Gly-Asp-binding domain of the integrin beta 3 subunit is sensitive to stimulation
- Source :
- Europe PubMed Central
- Publication Year :
- 1991
- Publisher :
- Elsevier BV, 1991.
-
Abstract
- The Arg-Gly-Asp (RGD)-binding domain of GPIIb-IIIa has been localized in a fragment of the GPIIIa subunit that includes the sequence between amino acids 109 and 171. To examine, in a platelet membrane environment, the activated versus nonactivated status of this domain, we have produced a monoclonal antibody against a synthetic peptide (residues 109-128) located within the RGD-binding region on GPIIIa. This kappa-IgM, named AC7, was specific for GPIIIa peptide 109-128 and interacted only with activated platelets. Fibrinogen, RGDF peptide, and the fibrinogen phi chain decapeptide LGGAKQAGDV inhibited the binding of AC7 to ADP-stimulated platelets. AC7 IgM and "small fragments" inhibited fibrinogen binding and platelet aggregation in a dose-dependent fashion. Induction of AC7 binding by D33C, a monoclonal antibody recognizing the GPIIb 426-437 sequence and stimulating fibrinogen binding, indicated that the GPIIb 426-437 and the GPIIIa 109-128 sequences were both involved in a stimulation-dependent conformational modification of the receptor. AC7 was able to recognize beta subunits other than GPIIIa on leucocyte surfaces but only after cell fixation with glutaraldehyde. The results are consistent with the implication of the RGD-binding domain in receptor ligand interaction on the platelet surface and its conformational modification and exposure upon receptor induction.
- Subjects :
- Integrins
Platelet Aggregation
Molecular Sequence Data
Fluorescent Antibody Technique
Platelet Membrane Glycoproteins
Biology
Platelet membrane glycoprotein
Sensitivity and Specificity
Biochemistry
Immunoglobulin kappa-Chains
hemic and lymphatic diseases
Humans
Amino Acid Sequence
Platelet activation
Binding site
Molecular Biology
Peptide sequence
Thrombin
Antibodies, Monoclonal
Fibrinogen
Fibrinogen binding
Cell Biology
Ligand (biochemistry)
Molecular biology
Peptide Fragments
Platelet aggregation inhibitor
Oligopeptides
Platelet Aggregation Inhibitors
Binding domain
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 266
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....37ca65a2ff288d07e43335deea17b6bd