Cross-Chimeric Analysis of Selectivity of Secretin and VPAC1 Receptor Activation 1 1 This work was supported by grants from the National Institutes of Health (DK46577) and the Fiterman Foundation. 2 2 These authors contributed equally to this work.

Agonist action at receptors is highly specific, affected by the structure of both ligand and receptor. Chimeric constructs of structurally related receptors and/or ligands that have biological differences provide an opportunity to correlate a specific structural domain with function. In this work, we have used a cross-chimeric approach to explore the structural basis for rat secretin and vasoactive intestinal polypeptide action at their closely …