Fig. 1.

Secretion and activity of carboxypeptidase A2 (CPA2) variants. HEK 293T cells were transfected with the indicated constructs, and conditioned medium was collected 48 h after transfection. A and B: levels of secreted CPA2 were determined by SDS-PAGE and Coomassie Blue staining as described in Methods. A: a representative gel is shown. The molecular mass markers were PageRuler Prestained Protein Ladder (PI-26616; Thermo Scientific). The arrow indicates bands for CPA2. B: densitometric quantitation of secreted CPA2 levels. Average values from 3 transfections with SD are indicated, expressed as percent of wild-type levels. C: activity of the CPA2 variants. CPA2 in the conditioned medium was activated with trypsin and chymotrypsin C, and carboxypeptidase activity was determined as described in Methods. Activity (average values ± SD, n = 3) was expressed as percent of wild type.