An Orally Active Bradykinin B<sub>1</sub> Receptor Antagonist Engineered as a Bifunctional Chimera of Sunflower Trypsin Inhibitor Yibo Qiu Misako Taichi Na Wei Huan Yang Kathy Qian Luo James P. Tam 10.1021/acs.jmedchem.6b01011.s002 https://acs.figshare.com/articles/journal_contribution/An_Orally_Active_Bradykinin_B_sub_1_sub_Receptor_Antagonist_Engineered_as_a_Bifunctional_Chimera_of_Sunflower_Trypsin_Inhibitor/4451189 An orally active and metabolically stable peptide TIBA was successfully engineered as a chimera by fusing an analgesic bradykinin receptor antagonist peptide and the trypsin inhibitory loop of sunflower trypsin inhibitor-1. As a fusion cyclic peptide, the metabolically labile analgesic peptide is protected from degradation by exopeptidases as well as the endopeptidases, and its serum half-life extended from <5 min to >6 h as a chimera. Moreover, the chimera TIBA was also found to be orally active in an animal pain model using a hot plate assay. 2016-12-05 00:00:00 serum half-life Sunflower Trypsin Inhibitor 6 h fusion cyclic peptide bradykinin receptor antagonist peptide sunflower trypsin inhibitor -1. Bifunctional Chimera plate assay metabolically peptide TIBA Bradykinin B 1 Receptor Antagonist Engineered animal pain model chimera TIBA