Answers are grounded in this paper and cite their sources.
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.
No takes yet. Share an insight, caveat, or question.
Metanis et al. (2004) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: