Figure 6

Biochemical properties of FAP-CFTRs and evidence of corrector rescue immunoblotting were performed on whole cell lysates from cells expressing CFTR. (A) HEK293 cells expressing either untagged or FAP-CFTR constructs. F508del constructs receiving treatment with correctors CFFT-002 + C18 or C4 + C18 for 24 h showed an accumulation of higher-molecular weight bands that were not present in the vehicle-treated control. FAP-F508del-CFTR corrected lanes have acquired a fully glycosylated C band, but corrected F508del-CFTR EL4-FAP shows incomplete glycosylation. (B) HBE cells expressing untagged F508del were treated with CFFT-002 and C18 either alone or in combination. Mature glycosylated bands were detected with a combination of corrector treatments but not under control conditions. These biochemical findings agree with the results from cell surface labeling and function (Figure 7D, Table 1). (C) Densitometry analysis of these immunoblots shows decreasing molecular weight from left to right. Clear differences are observed between the combination of corrector treatment and vehicle.