Fig. 2. Assembly and secretion of lam5 and 6. ³⁵S-labeled proteins were immunoprecipitated from the conditioned media of HFK or JEBG keratinocytes (JEBG) using the indicated Mabs (D2-1, C2-5, etc.). Before incubation with antibodies, one half of the collected media was digested with or without thrombin (+/– thrombin; 1 NIH unit/ml for 2 hours). The precipitates were separated by 6% SDS-PAGE. Lane 1, Mab D2-1 specific for the human 3 G4/5 domains; lane 2, Mab C2-5 specific for the human 3 chain; lane 3, Mab B4-6 specific for the human 2 chain; lane 4, Mab G2'-1 specific for the 170 kDa thrombospondin (TSP).