TRANSFER NUCLEAR OVERHAUSER EFFECT STUDY OF THE CONFORMATION OF OXYTOCIN BOUND TO BOVINE NEUROPHYSIN-I.

This study reports the structure of the peptide hormone oxytocin bound to its carrier protein, neurophysin I, obtained by nuclear magnetic resonance techniques. At the pH value of 2.1 in our experiments, the ligand is in fast exchange with its carrier protein, allowing the use of transfer-NOE methods. The number of distance constraints for the peptide being limited, considerable attention has been paid to an accurate distance determination. The resulting accurate distance limits were used as input for a distance geometry calculation followed by a restrained molecular dynamics run. Convergence to a well-defined family of structures for oxytocin in its bound state was reached