Vibrationally enhanced tunneling as a mechanism for enzymatic hydrogen transfer.

Enzymatic H Transfers: Quantum Tunneling and Coupled Motion from Kinetic Isotope Effect Studies

Many hydrogen transfer processes exhibit nonclassical behavior due to inherent quantum mechanical properties of the hydrogen. Investigation of various enzymes under physiological conditions indicates that hydrogen transfer processes often show significant quantum mechanical behavior. Traditionally, this phenomenon was treated in terms of a tunneling correction to classical or semiclassical mode...

Vibrationally enhanced hydrogen tunneling in the Escherichia coli thymidylate synthase catalyzed reaction.

The enzyme thymidylate synthase (TS) catalyzes a complex reaction that involves forming and breaking at least six covalent bonds. The physical nature of the hydride transfer step in this complex reaction cascade has been studied by means of isotope effects and their temperature dependence. Competitive kinetic isotope effects (KIEs) on the second-order rate constant (V/K) were measured over a te...

Dynamic barriers and tunneling . New views of hydrogen transfer in enzyme reactions *

Hydrogen-transfer processes are expected to show appreciable quantum mechanical behavior. Intensive investigations of enzymes under their physiological conditions show this to be true in practically every example investigated. Initially, tunneling was treated either as a tunneling correction [cf. Bell, The Tunnel Effect in Chemistry, Chapman & Hall, New York, (l980)], or as corner-cutting [Truh...

Current Issues in Enzymatic Hydrogen Transfer from Carbon: Tunneling and Coupled Motion from Kinetic Isotope Effect Studies

Spectroscopy and Energy Transfer of Molecular Transients: Hydrogen Isocyanide and the Ketenyl Radical

Energy transfer from molecular species has been a long standing topic of profound interest to the chemical physics community. It is worth noting however, that to date, most studies have preferentially focused on chemically stable molecular species. While the literature does contain numerous examples of energy transfer of small radical or chemically unstable species, there have been extremely fe...