HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Steiner, B. Articles by Phillips, D. R. Search for Related Content PubMed PubMed Citation Articles by Steiner, B. Articles by Phillips, D. R. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 266, Issue 23, 14986-14991, 08, 1991

Ca(2+)-dependent structural transitions of the platelet glycoprotein IIb-IIIa complex. Preparation of stable glycoprotein IIb and IIIa monomers

B Steiner, LV Parise, B Leung and DR Phillips
Gladstone Foundation Laboratories for Cardiovascular Disease, University of California, San Francisco 94140-0608.

The platelet membrane glycoprotein (GP) IIb-IIIa complex is the receptor for adhesive proteins on activated platelets that mediates platelet aggregation. In the present study, factors affecting the structural stability of the purified GP IIb-IIIa complex and the dissociated subunits were investigated. Purified GP IIb-IIIa was incubated in various Ca2+ concentrations, and the percentage of dissociated subunits was quantitated by sucrose gradient sedimentation. Two Ca(2+)-dependent transitions were observed, one at about 60 microM Ca2+, where half of the complexes became dissociated, and the other at 0.1 microM Ca2+, where half of the dissociated subunits became incapable of reforming heterodimer complexes when higher Ca2+ concentrations were readded. This loss in ability to reform heterodimer complexes was caused primarily by a Ca(2+)-dependent transition in GP IIIa, leading to an apparent unfolding of this subunit, followed by the formation of high molecular weight aggregates. The formation of these aggregates was time- and temperature-dependent and could not be reversed by added Ca2+. Although Mg2+ prevented dissociation of GP IIb- IIIa, it failed to promote reassociation of the dissociated subunits. Based on these findings, conditions were developed for the preparation of dissociated GP IIb and GP IIIa such that 70% of the subunits remained functional in that they retained the ability to reform heterodimer complexes.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				D. W. Bougie, P. R. Wilker, E. D. Wuitschick, B. R. Curtis, M. Malik, S. Levine, R. N. Lind, J. Pereira, and R. H. Aster Acute thrombocytopenia after treatment with tirofiban or eptifibatide is associated with antibodies specific for ligand-occupied GPIIb/IIIa Blood, August 28, 2002; 100(6): 2071 - 2076. [Abstract] [Full Text] [PDF]