The anomalous pKa of Tyr-9 in glutathione S-transferase A1-1 catalyzes product release.

@article{Ibarra2003TheAP,
  title={The anomalous pKa of Tyr-9 in glutathione S-transferase A1-1 catalyzes product release.},
  author={Catherine A Ibarra and Pramit Chowdhury and Jacob W Petrich and William M Atkins},
  journal={The Journal of biological chemistry},
  year={2003},
  volume={278 21},
  pages={19257-65}
}
The pKa of the catalytic Tyr-9 in glutathione S-transferase (GST) A1-1 is lowered from 10.3 to approximately 8.1 in the apoenzyme and approximately 9.0 with a GSH conjugate bound at the active site. However, a clear functional role for the unusual Tyr-9 pKa has not been elucidated. GSTA1-1 also includes a dynamic C terminus that undergoes a ligand-dependent disorder-to-order transition. Previous studies suggest a functional link between Tyr-9 ionization and C-terminal dynamics. Here we directly… CONTINUE READING