title: Platelet thrombospondin haemagglutinin activity is due to aggregate formation.
abstract: Thrombospondin released from human blood platelets by thrombin activation formed high molecular weight aggregates which co-eluted with haemagglutinin activity on Sepharose 4B gel filtration. Thrombospondin aggregation was mediated by intermolecular disulphide bridges. The aggregates consisted of a series of oligomers ranging from a dimer to polymeric forms with Mr congruent to 40 X 10(6). Native monomeric thrombospondin obtained by a modified procedure was deficient in haemagglutination activity but inhibited haemagglutination induced by aggregated thrombospondin.
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000032:analysis / Q000302:isolation & purification / Q000502:physiology*; D006384:Hemagglutination; D006801:Humans; D066298:In Vitro Techniques; D019699:Thrombospondins
chemical_list: D006023:Glycoproteins; D019699:Thrombospondins