title: Protease action and generation of beta-thromboglobulin-like protein followed by platelet activation.
abstract: beta-Thromboglobulin (betaTG) is a platelet specific protein present in the alpha-granules and secreted into the surrounding medium on cell activation. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of platelet releasate after inhibition of metalloproteinases with ethyleneglycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid (EGTA) showed disappearance of an 8.0-kDa band. In the absence of the cation chelators, a 48-kDa band disappeared and concurrently, the 8.0-kDa band intensity increased suggesting that the former may be the immediate precursor of the latter. The Western blot stained using specific antibodies, isolated from single-cell clones of hybridoma, against 8.0-kDa protein recognized not only 48- and 8.0-kDa bands but few others too. The data suggest that one or more high molecular weight (HMW) protein is released from alpha-granules and is broken down into smaller fragments after release to form beta-thromboglobulin (beta-TG)-like proteins by the action of metal-dependent proteases.
authors.affiliation: Biomedical Technology Wing, Thrombosis Research Unit, Sree Chitra Tirunal Institute for Medical sciences and Technology, 695012, Trivandrum, India.
authors.forename: K R
authors.initials: KR
authors.lastname: Resmi
authors.forename: Lissy K
authors.initials: LK
authors.lastname: Krishnan
mesh_terms: D000911:Antibodies, Monoclonal; D001792:Blood Platelets / Q000201:enzymology / Q000648:ultrastructure; D015153:Blotting, Western; D003594:Cytoplasmic Granules / Q000737:chemistry; D004533:Egtazic Acid; D006493:Heparin / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008666:Metalloendopeptidases / Q000378:metabolism*; D008970:Molecular Weight; D015539:Platelet Activation; D011498:Protein Precursors / Q000032:analysis* / Q000378:metabolism; D001620:beta-Thromboglobulin / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D011498:Protein Precursors; D001620:beta-Thromboglobulin; D004533:Egtazic Acid; D006493:Heparin; D008666:Metalloendopeptidases