Structure-activity relationship studies on the novel neuropeptide orphanin FQ.

摘要: Abstract The heptadecapeptide orphanin FQ (OFQ) is an endogenous ligand to opioid-like G protein-coupled receptor. Although the primary structure of OFQ exhibits some similarity opioid peptides, not recognized by receptors nor does receptor bind ligands. In order investigate structural determinants this ligand/receptor selectivity, we conducted a systematic structure-activity study on characterize which sites molecule are important for activation. Alanine- and D-amino acid-scanning mutagenesis revealed several residues in amino-terminal half participate both binding Most strikingly, Phe1 position could be changed tyrosine without loss biological activity. addition, seemed require recognition complete peptide These results indicate that mode interaction with its may different from peptides their respective might therefore account observed selectivity.