Isolation and initial biochemical characterisation of caps of two major rat thymocyte glycoproteins: evidence for the involvement of a 205 K Con A binding protein and cytoskeletal components in capping.
Two major rat thymocyte surface glycoproteins, the leucocyte-common (L-C) antigen and the leucocyte sialoglycoprotein (LSGP), were induced to cap independently, using the specific monoclonal antibodies OX-1 and W3/13, respectively, and an appropriate fluorescently labeled second antibody layer. The caps were subsequently isolated from detergent extracted cells by a procedure involving gentle shearing. TRITC-phalloidin staining of the isolated caps demonstrated the presence of F-actin within these structures, and lectin-affinity staining after fractionation on SDS polyacrylamide gels revealed the presence of a concanavalin A (Con A) binding protein of relative molecular weight (Mr) 205,000, gp205, in both the L-C antigen and LSGP caps, but absent from the detergent-insoluble residue isolated from unchallenged cells. These results suggest that gp205 may be involved in the association of cross-linked glycoproteins with the cytoskeleton during capping.
D000818:Animals; D000941:Antigens / Q000032:analysis; D003208:Concanavalin A / Q000378:metabolism; D003599:Cytoskeleton / Q000276:immunology*; D005260:Female; D007152:Immunologic Capping; D008970:Molecular Weight; D051381:Rats; D011917:Rats, Inbred Lew; D011952:Receptors, Concanavalin A / Q000276:immunology / Q000302:isolation & purification*; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D011952:Receptors, Concanavalin A; D003208:Concanavalin A