Acid-base chemical mechanism of O-acetylserine sulfhydrylases-A and -B from pH studies.

@article{Tai1995AcidbaseCM,
  title={Acid-base chemical mechanism of O-acetylserine sulfhydrylases-A and -B from pH studies.},
  author={C. H. Tai and Srinivasa R. Nalabolu and John Wiseman Simmons and Tim Jacobson and Paul F. Cook},
  journal={Biochemistry},
  year={1995},
  volume={34 38},
  pages={12311-22}
}
The pH dependence of kinetic parameters using natural and alternative reactants was determined in order to obtain information on the chemical mechanisms of the A and B isozymes of O-acetylserine sulfhydrylase (OASS) from Salmonella typhimurium. A general mechanism is proposed for OASS in which OAS binds with its alpha-amine unprotonated to carry out a nucleophilic attack on C4' of the protonated Schiff base and with the acetyl carbonyl hydrogen-bonded to a protonated enzyme group (or a water… CONTINUE READING