Open AccessA monoclonal antibody against human thrombospondin inhibits platelet aggregation.
Author(s) -
Vishva M. Dixit,
Doris M. Haverstick,
Karen O’Rourke,
Sally W. Hennessy,
Gregory A. Grant,
Samuel A. Santoro,
William A. Frazier
Publication year - 1985
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.82.10.3472
Subject(s) - thrombospondin , monoclonal antibody , epitope , chemistry , biochemistry , thrombin , peptide , microbiology and biotechnology , platelet , epitope mapping , peptide sequence , immunoprecipitation , platelet activation , antibody , biology , enzyme , metalloproteinase , gene , immunology
A monoclonal antibody (C6.7) has been generated against the calcium-replete form of human platelet thrombospondin (TSP). C6.7 is specific for TSP as determined by both competitive radioimmunoassay and immunoprecipitation. This antibody inhibits both thrombin- and A23187-induced aggregation of gel-filtered platelets in a concentration-dependent manner without affecting the secretion of serotonin. The epitope on TSP recognized by C6.7 has been localized to an 18-kDa fragment that is present in mild chymotryptic digests of TSP. This fragment is disulfide-linked to a 120- to 140-kDa fragment in unreduced digests, and both reduction and denaturation are required to separate the 18-kDa peptide from the larger fragments. A 25-kDa heparin binding domain is also present in the chymotryptic digest. However, the 18-kDa peptide is distinct from the heparin binding domain. The amino acid sequence at the NH2 terminus of the 18-kDa fragment is Asp-Thr-Asn-Pro-Thr-Arg-Ala-Gln-Gly-Tyr-.