BMB Reports

Korean Society for Biochemistry and Molecular Biology (생화학분자생물학회)
권호 표지

Kinetics and Mechanism of Mutant O-acetylserine Sulfhydrylase-A (C43S) from Salmonella typhimurium LT-2

  • Received : 1996.01.06
  • Published : 1996.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

The pH dependence of the kinetic parameters of mutant O-acetylserine sulfhydrylase (OASS) from Salmonella typhimurium LT-2 has been determined in order to obtain information on the chemical mechanism. The initial velocity pattern obtained by varying the concentrations of OAS at several fixed concentrations of TNB, shows an intersection on the left of the ordinate at pH 7.0, indicating that the kinetic mechanism is a sequential mechanism in which substrate inhibition by OAS is observed while the wild type enzyme showed a ping pong mechanism. The values of $V/E_t$, $V/K_{OAS}E_{t}$ and $V/K_{TNB}E_{t}$ decreased by about 68%, 14% and 16% as compared with the wild type enzyme. The $V/K_{OAS}E_{t}$ is a pK of 6.5 on the acid side of the pH profile, and the $V/K_{TNB}$ is pH independent. As compared with the wild type enzyme, the pKs in the V/K profiles are shifted, reflecting that binding of the cofactor in free E:OAS is less asymmetric.

Keywords

References

  1. J. Biol. Chem. v.244 Becker, M.A.;Kredich, N.M.;Tomkins, G.M.
  2. Photochem. Photobiol. v.18 Burstein, E.A.;Vedenkina, N.S.;Ivkova, M.N. https://doi.org/10.1111/j.1751-1097.1973.tb06422.x
  3. J. Bacteriol. v.170 Byme, C.R.;Monroe, R.S.;Ward, K.A.;Kredich, N.M. https://doi.org/10.1128/jb.170.7.3150-3157.1988
  4. Adv. Enzymol. Relat. Areas Mol. Biol. v.45 Cleland, W.W.
  5. Adv. Methods Enzymol. v.63 Clehand, W.W.
  6. Molecular Microbiology v.13 Colyer, T.E.;Kredich, N.M. https://doi.org/10.1111/j.1365-2958.1994.tb00472.x
  7. Biochemistry v.31 Cook, P.F.;Hara, S.;Nalabolu, S.Rl.;Schnackerz, K. https://doi.org/10.1021/bi00123a013
  8. J. Biol. Chem. v.251 Cook, P.F.;Wedding, R.T.
  9. Arch. Biochem. Biophys. v.82 Ellman, G.L. https://doi.org/10.1016/0003-9861(59)90090-6
  10. J. Gen. Microbiol. v.128 Filutowicz, M.;Waiter, A.;Hulanicka, D.
  11. Protein Expression and Prification v.1 Hara, S.;Payne, M.A.;Schnackerz, K.D.;Cook, P.F. https://doi.org/10.1016/1046-5928(90)90048-4
  12. J. Bacteriol. v.140 Hulanika, M.D.;Haiiquist, S.G.;Kredich, N.M.;Majica, A.T.
  13. J. Biol. Chem. v.246 Krendich, N.M.
  14. J. Biol. Chem. v.244 Kredich, N.M.;Bechker, M.A.;Tomkins, G.M.
  15. J. Biol. Chem. v.241 Kredich, N.M.;Tomkins, G.M.
  16. Mol. Microbiol. v.2 Levy, S.;Danchin, A. https://doi.org/10.1111/j.1365-2958.1988.tb00089.x
  17. J. Biol. Chem. v.263 Marceau, M.;Lewis, S.D.;Shafer, J.A.
  18. J. Bacteriol. v.158 Nakamula, T.;Iwahashi, H.;Eguchi, Y.
  19. Amino Acids v.2 Nalabolu, S.R.;Tai, C.H.;Schnackerz, K.D.;Cook, P.F. https://doi.org/10.1007/BF00806082
  20. Biochemistry Nalabolu, S.R.;Schnackerz, K.D.;Cook, P.F.
  21. J. Biochem. Mol. Biol. (formerly Korean Biochem. J.) v.29 Park, J.B.;Kim, S.K.;Yoon, M.Y.
  22. Biochemistry v.18 Schnackerz, K.D.;Ehrlich, J.H.;Giessman, W.;Reed, T.A. https://doi.org/10.1021/bi00583a019
  23. Biochemistry v.32 Tai, C.H.;Nalabolu, S.R.;Jacobson, T.M.;Minter, D.E.;Cook, P.E. https://doi.org/10.1021/bi00076a017