title: Location and partial characterization of the heparin-binding fragment of platelet thrombospondin.
abstract: Purified platelet thrombospondin (TS) was subjected to proteolysis with a number of proteases including factors IXa, Xa, thrombin, elastase, trypsin, and chymotrypsin. All enzymes yielded fragments of TS which bound to heparin-Sepharose. Only chymotrypsin cleavage produced a single species of heparin-binding fragment, as analyzed by SDS-PAGE. This fragment had a chain molecular weight of 28,000, and contained no interchain disulfide bonds. Amino acid sequence analysis of the heparin-binding fragment and of TS revealed a single sequence, indicating that the fragment constitutes the amino-terminal domain of TS and that the three chains in TS are identical in this region.
mesh_terms: D000595:Amino Acid Sequence; D001792:Blood Platelets / Q000502:physiology*; D002918:Chymotrypsin / Q000378:metabolism; D005170:Factor X / Q000378:metabolism; D015951:Factor Xa; D006023:Glycoproteins / Q000302:isolation & purification / Q000502:physiology*; D006493:Heparin / Q000097:blood*; D006801:Humans; D007106:Immune Sera; D010196:Pancreatic Elastase / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D013917:Thrombin / Q000378:metabolism; D019699:Thrombospondins; D014357:Trypsin / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D007106:Immune Sera; D010446:Peptide Fragments; D019699:Thrombospondins; D005170:Factor X; D006493:Heparin; D002918:Chymotrypsin; D010196:Pancreatic Elastase; D014357:Trypsin; D013917:Thrombin; D015951:Factor Xa