Fig. 4. α1-PDX inhibits D187N variant processing. (A) BHK cells were transfected with the D187N variant. Following 5 h of expression, the indicated amount of peptide inhibitor (dRVKRck) was added to the medium for 1 h, cells were washed, and the intracellular or secreted full-length and C68 forms recovered after a 2 h time period were analyzed by SDS–PAGE and immunoblotting. (B) Upper panel: BHK cells were co-transfected with the D187N variant and α1-PDX. Following 6 h of expression, cells were washed, and the intracellular or secreted full-length and C68 forms recovered after a 2 h time period were analyzed by immunoblotting. Lower panel: quantitation of data presented in the upper panel. Asterisks indicate low levels (<1%) of cross-reacting protein(s). The results are typical of two independent experiments.