Tunneling and coupled motion in the Escherichia coli dihydrofolate reductase catalysis.
H-transfer was studied in the complex kinetic cascade of dihydrofolate reductase. Intrinsic kinetic isotope effects, their temperature dependence, and other temperature-dependent parameters indicated H-tunneling, but no 1 degrees to 2 degrees coupled motion. The data also suggested environmentally coupled tunneling and commitment to catalysis on pre-steady-state isotope effects.
Sikorski
R Steven
RS
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA.
Wang
Lin
L
Markham
Kelli A
KA
Rajagopalan
P T Ravi
PT
Benkovic
Stephen J
SJ
Kohen
Amnon
A
D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D007700:Kinetics; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism*
D013762:Tetrahydrofolate Dehydrogenase