Thromb Haemost 1992; 67(02): 252-257
DOI: 10.1055/s-0038-1648421
Original Articles
Schattauer GmbH Stuttgart

Binding of Human Platelet Glycoprotein lb and Actin to Fragments of Actin-Binding Protein

Anne M Aakhus
The Research Institute for Internal Medicine, Rikshospitalet, The National Hospital, University of Oslo, Oslo, Norway
,
J Michael Wilkinson
1   The Department of Biochemistry and Cell Biology, Royal College of Surgeons of England, London, UK
,
Nils Olav Solum
The Research Institute for Internal Medicine, Rikshospitalet, The National Hospital, University of Oslo, Oslo, Norway
› Author Affiliations
Further Information

Publication History

Received 19 March 1991

Accepted after revision 06 September 1991

Publication Date:
02 July 2018 (online)

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Summary

Actin-binding protein (ABP) is degraded into fragments of 190 and 90 kDa by calpain. A monoclonal antibody (MAb TI10) against the 90 kDa fragment of ABP coprecipitated with the glycoprotein lb (GP lb) peak observed on crossed immunoelectrophoresis of Triton X-100 extracts of platelets prepared without calpain inhibitors. MAb PM6/317 against the 190 kDa fragment was not coprecipitated with the GP lb peak under such conditions. The 90 kDa fragment was adsorbed on protein A agarose from extracts that had been preincubated with antibodies to GP lb. This supports the idea that the GP Ib-ABP interaction resides in the 90 kDa region of ABP. GP lb was sedimented with the Triton-insoluble actin filaments in trace amounts only, and only after high speed centrifugation (100,000 × g, 3 h). Both the 190 kDa and the 90 kDa fragments of ABP were sedimented with the Triton-insoluble actin filaments.