Binding of human platelet glycoprotein Ib and actin to fragments of actin-binding protein.
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 Ib (GP Ib) 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 Ib peak under such conditions. The 90 kDa fragment was adsorbed on protein A agarose from extracts that had been preincubated with antibodies to GP Ib. This supports the idea that the GP Ib-ABP interaction resides in the 90 kDa region of ABP. GP Ib was sedimented with the Triton-insoluble actin filaments in trace amounts only, and only after high speed centrifugation (100,000 x g, 3 h). Both the 190 kDa and the 90 kDa fragments of ABP were sedimented with the Triton-insoluble actin filaments.
Aakhus
A M
AM
Research Institute for Internal Medicine, Rikshospitalet, Oslo, Norway.
Wilkinson
J M
JM
Solum
N O
NO
D000199:Actins / Q000378:metabolism*; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity / Q000276:immunology; D015153:Blotting, Western; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D008840:Microfilament Proteins / Q000378:metabolism*; D008970:Molecular Weight; D017830:Octoxynol; D010446:Peptide Fragments / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D011092:Polyethylene Glycols; D011233:Precipitin Tests; D011485:Protein Binding
D000199:Actins; D000911:Antibodies, Monoclonal; D003902:Detergents; D008840:Microfilament Proteins; D010446:Peptide Fragments; D010980:Platelet Membrane Glycoproteins; D011092:Polyethylene Glycols; D017830:Octoxynol