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. 2015 Apr 13;10(4):e0123180. doi: 10.1371/journal.pone.0123180

Fig 5. Co-expression of WT and mutant proCPA6 in HEK293T cells.

Fig 5

HAH6-tagged or FLAG-tagged wild-type (WT) and HAH6-tagged mutant proCPA6 were co-expressed in HEK293T cells by transient transfection and ECM was analyzed. (A) Enzyme activity of CPA6 in the ECM was assayed using 3-(2-furyl)-acryloyl-Phe-Phe. In co-expression experiments, approximately 55–65% activity was seen when WT-CPA6-FLAG was coexpressed with either of the two inactive mutants (Asn271Ser and Glu398Gln), with the Arg36His mutant, or with empty pcDNA vector; the difference in means between these 4 groups was not statistically significant. (B) HA-tag immunoreactivity in the ECM, measured by western blotting, showed a 50% reduction for Arg36His-CPA6 while levels were unchanged for Asn271Ser and Glu398Gln mutants. Error bars show standard error of the mean in panels A (n≥7) and B (n≥4). **, p<0.01.