PLATELET PROTEIN ORGANIZATION - ANALYSIS BY TREATMENT WITH MEMBRANE-PERMEABLE CROSS-LINKING REAGENTS

  • 1 January 1982
    • journal article
    • research article
    • Vol. 59  (3) , 502-513
Abstract
Platelet protein organization was examined by treatment of intact resting or thrombin-activated platelets with 2 cross-linking reagents, diamide or dithiobis(succinimidyl propionate) (DTSP). Cross-linked complexes were separated by polyacrylamide gel electrophoresis in the absence of reducing agent and their composition determined after reductive cleavage and analysis in a 2nd-dimensional gel. The most prominent cross-linked species produced by diamide treatment of resting platelets are cytoskeletal protein homopolymers, such as myosin heavy chain dimer and actin oligomers, and high MW material consisting of homo- or heteropolymers of cytoskeletal proteins and 230,000, 170,000, 100,000, 55,000 and 52,000 dalton proteins. DTSP treatment forms similar complexes and also cross-links membrane glycoproteins IIb and III into high MW material. Thrombin activation of platelets before treatment with diamide or DTSP results in increased cross-linking of myosin and increased incorporation of several proteins, particularly myosin and glycoproteins IIb and III, into high MW material. The results provide evidence for reorganization of cytoskeletal and membrane proteins during platelet function.