Fig. 8
From: Secretion of Fc-amidated peptide fusion proteins by Chinese hamster ovary cells
Bioassay of purified Fc-PYY fusion proteins. CHO cells expressing the NPY-2R were used to assess the ability of Fc-PYY fusion proteins purified from the spent medium of different CHO lines to inhibit forskolin-stimulated cAMP production; PYY binding to NPY-2R activates Gαi, decreasing cAMP production. Synthetic PYY(3–36)NH2 was more potent than synthetic GP-PYY-NH2; synthetic GP-PYY-Gly was at least 10,000-fold less potent than the corresponding amidated peptide. Although the Fc-PYY fusion protein produced by PAM1 cells was about 200-fold less active than synthetic GP-PYY-NH2, it was 10-fold more active than synthetic GP-PYY-Gly. Parallel dose–response curves were observed for all of the peptides and proteins tested