FIGURE 5.

Identification of CFTR NBD fragments produced by limited Arg-C digestion by Western blot analysis. CFTR was solubilized, immunoprecipitated, and subjected to partial proteolysis with the proteinase Arg-C as described in the legend to Fig. 4. After fractionating on 16% Tricine gel, Western blots (WB) were probed with monoclonal antibodies to NBD1 (L12B4) and NBD2 (M3A7 and 596). These antibodies recognize epitopes within the following CFTR amino acid sequences: L12B4, 385–410; 596, 1204–1211; M3A7, 1373–1382 (42). Bands 1–5 were identified by comparing autoradiographs and Western blots of the same gels.