Bound ligand motion in crystalline carboxypeptidase A.

  title={Bound ligand motion in crystalline carboxypeptidase A.},
  author={Huaye Zhang and Robert G. Bryant},
  journal={Biophysical journal},
  volume={72 1},
Deuterium NMR spectra for the phenyl ring deuterons have been obtained for D-phenylalanine, L-phenylalanine, phenylacetic acid, and phenyl propionic acid in randomly oriented crystals of carboxypeptidase A as a function of water content. The spectra are analyzed using a two-site jump model for phenyl ring pi-flips when the ligand is bound to the protein, and the model includes the possibility that the ligand may exchange with isotropic or unbound environments within the crystal. Although the… CONTINUE READING