Concanavalin A induces interactions between surface glycoproteins and the platelet cytoskeleton.

摘要: We have measured the association of platelet surface membrane proteins with Triton X-100 (Triton)-insoluble residues in platelets labeled 125I. In both concanavalin A (Con A)-stimulated and resting platelets, this fraction is composed largely polypeptides apparent molecular weights 45,000, 200,000, 250,000 which comigrate authentic actin, myosin heavy chain, actin binding protein, respectively, as judged by PAGE SDS. Less than 10% two major 125I-labeled glycoproteins, GPiib GPIII, were associated residue platelets. Within 45 s after Con addition, 80-95% these glycoproteins became amount sedimentable doubled. No cosedimentation GPIIb III cytoskeletal protein-containing was seen when added to a extract cells, indicating that sedimentation A-stimulated not due precipitation detergent lysis. Treatment extracts DNase I (deoxyribonucleate 59-oligonucleotidido-hydrolase [EC 3.1.4.5]) inhibited dose-dependent manner. This inhibition an effect on A-glycoprotein interactions since could be quantitatively recovered A-Sepharose affinity absorption presence I. When bound localized ultrastructurally, it cell-sized structures containing filamentous material. intact there simultaneous immunofluorescent coredistribution surface-bound under conditions induced redistribution myosin. These data suggest can, platelet, induce physical between certain internal cytoskeleton.