Electrostatic interactions dominate the catalytic contribution of arg39 in 4-oxalocrotonate tautomerase

J Am Chem Soc. 2004 Oct 13;126(40):12726-7. doi: 10.1021/ja0463841.

Abstract

The synthesis and kinetic parameters of a comprehensive set of 4-OT analogues with arginine (X = NH2+) to citrulline (X = O) substitutions at positions 11, 39, and 61 are reported. These data suggest that the main contribution of Arg39' ' to catalysis is by electrostatic stabilization of the anionic transition state leading to intermediate 2, and not by hydrogen bonding.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Substitution
  • Arginine / chemistry*
  • Arginine / metabolism*
  • Catalysis
  • Circular Dichroism
  • Citrulline / chemistry
  • Citrulline / metabolism
  • Isomerases / chemistry*
  • Isomerases / metabolism*
  • Kinetics
  • Protein Folding
  • Static Electricity

Substances

  • Citrulline
  • Arginine
  • 4-oxalocrotonate tautomerase
  • Isomerases