@article {KLUH414, author = {IVAN KLUH and EVA SEDL{\'A}KOV{\'A} and TOMISLAV BARTH and JOSEPH H. CORT}, title = {Neurophysin Binding of Vasopressin Analogues Altered at the NH2- and COOH-Terminal Positions}, volume = {9}, number = {3}, pages = {414--420}, year = {1973}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {Binding studies were carried out at pH 5.8 with bovine neurophysin II and two series of analogues of lysine-vasopressin. In one series the peptide chain of the parent hormone was extended at the NH2 terminus by 1 leucine or 1 phenylalanine residue or by 1, 2, or 3 glycine residues, which represented a progressive steric separation of the Nα-amino group from the cyclic portion of the molecule. The second series of analogues consisted of shortened peptide chains at the COOH terminus, enzymatically prepared, and involved the removal of glycinamide from sequence position 9 and both terminal amino acids, lysine and glycine. Gel filtration was used to separate the neurophysin from the small peptide moieties, and spectrophotometry, dansylation analysis, and biological activity were used to investigate the fractional positions of the small peptides in the eluate. There was clear evidence of neurophysin binding of the parent hormone itself and the analogue shortened at the COOH termini. None of the analogues extended at the NH2 termini showed any binding. This is taken as evidence that only the composition of the NH2 terminus is critical for binding of the intact hormone molecule to neurophysin, provided that the Nα-amino group not only is present and free but also is not sterically separated from an adjacent aromatic side chain. ACKNOWLEDGMENTS The authors would like to express their gratitude to each of the Prague and Malmo chemists cited in the text for supplying their synthetic and isolation products, to Dr. Jan Mulder of Ferring, Ltd., for the collaboration of that firm, and to Dr. K. Jo{\v s}t of this Institute for valuable and critical advice.}, issn = {0026-895X}, URL = {https://molpharm.aspetjournals.org/content/9/3/414}, eprint = {https://molpharm.aspetjournals.org/content/9/3/414.full.pdf}, journal = {Molecular Pharmacology} }