Stoichiometric arginine binding in the oxygenase domain of inducible nitric oxide synthase requires a single molecule of tetrahydrobiopterin per dimer.

@article{Rafferty1999StoichiometricAB,
  title={Stoichiometric arginine binding in the oxygenase domain of inducible nitric oxide synthase requires a single molecule of tetrahydrobiopterin per dimer.},
  author={Steven Patrick Rafferty and Jeffrey C. Boyington and R Kulansky and Peter D. Sun and Harry L Malech},
  journal={Biochemical and biophysical research communications},
  year={1999},
  volume={257 2},
  pages={344-7}
}
In addition to its catalytic roles, the nitric oxide synthase (NOS) cofactor tetrahydrobiopterin (H4B) is required for substrate binding and for stabilization of the dimeric structure. We expressed and purified the core of the iNOS oxygenase domain consisting of residues 75-500 (CODiNOS) in the presence (H4B+) and absence (H4B-) of this cofactor. Both forms bound stoichiometric amounts of heme (>0.9 heme per protein subunit). H4B- CODiNOS was unable to bind arginine, gave an unstable ferrous… CONTINUE READING