Deuteron magnetic resonance studies on the microdynamical behavior of partially deuterated oxytocin with neurophysin

With the use of specifically deuteron-labeled oxytocin and related molecules, deamino oxytocin and prolyl-leucyl-glycinamide, some of the intramolecular micro-mica of the free molecules and their interactions with their biological carriers, the neurophysins, have been studied. The work involves contemporary synthetic and isolation chemical techniques and computer processed nuclear magnetic resonance spectroscopy. The results show that there is considerable intramolecular motion in the "tail" of oxytocin with respect to the remainder of the molecule and that there is a rapid dynamical equilibrium between neurophysin-bound and free hormone in solution. The implications of this work on the biological action of the hormone-protein complex are discussed as well as the interpretation of high resolution nuclear magnetic resonance data in the light of these results.