Imbalanced tunneling ready states in alcohol dehydrogenase model reactions: rehybridization lags behind H-tunneling.
The secondary kinetic isotope effects for the hydride transfer reactions from aliphatic alcohols to two carbocations (NAD(+) models) in acetonitrile were determined. The results suggest that the hydride transfer takes place by tunneling and that the rehybridizations of both donor and acceptor carbons lag behind the H-tunneling. This is quite contrary to the observations in alcohol dehydrogenases where the importance of enzyme motions in catalysis is manifested.
Department of Chemistry, Southern Illinois University Edwardsville, Edwardsville, IL 62026, USA.
Blake
B
Hammann
Mortezaali
M
Razzaghi
Sadra
S
Kashefolgheta
Yun
Y
Lu
D000097:Acetonitriles / Q000737:chemistry; D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D000438:Alcohols / Q000737:chemistry; D055162:Biocatalysis; D002412:Cations / Q000737:chemistry; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry; D006860:Hydrogen Bonding; D007700:Kinetics; D008956:Models, Chemical
D000097:Acetonitriles; D000438:Alcohols; D002412:Cations; D006575:Heterocyclic Compounds, 3-Ring; C430851:xanthylium; D000426:Alcohol Dehydrogenase; C032159:acetonitrile