title: The role of some polar amino acid residues in secretin.
abstract: Three analogues of S5-27, the tricosapeptide with the carboxyl-terminal sequence of secretin, were studied. In the analogues, the acidic residues at positions 9 and 15 of S5-27 were replaced by the neutral residues glutamine and asparagine. These changes resulted in a decrease in immunoreactivity. Binding to an antibody against secretin could be correlated with the changes in the conformation of the synthetic analogues.
mesh_terms: D000595:Amino Acid Sequence; D000937:Antigen-Antibody Reactions; D012633:Secretin / Q000031:analogs & derivatives* / Q000276:immunology; D014660:Vasoactive Intestinal Peptide / Q000276:immunology
chemical_list: D012633:Secretin; D014660:Vasoactive Intestinal Peptide