Efforts toward the direct experimental characterization of enzyme microenvironments: tyrosine100 in dihydrofolate reductase
D. Groff, M.C. Thielges, S. Celliti, P.G. Schultz, F.E. Romesberg, Angew. Chem., Int., Ed., (2009) 48:3478-3481.
Site-specific deuteration and FT-IR studies reveal that Tyr100 in DHFR plays an important role in catalysis, with a strong electrostatic coupling occuring between Tyr100 and the charge that develops in the hydride-transfer transition state.