𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Insights into the mechanisms of flavoprotein oxidases from kinetic isotope effects

✍ Scribed by Paul F. Fitzpatrick

Publisher
John Wiley and Sons
Year
2007
Tongue
French
Weight
167 KB
Volume
50
Category
Article
ISSN
0022-2135

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Deuterium, solvent, and ^15^N kinetic isotope effects have been used to probe the mechanisms by which flavoproteins oxidize carbon–oxygen and carbon–nitrogen bonds in amines, hydroxy acids, and alcohols. For the amine oxidases D‐amino acid oxidase, N‐methyltryptophan oxidase, and tryptophan monooxygenase, D‐serine, sarcosine, and alanine are slow substrates for which CH bond cleavage is fully rate limiting. Inverse isotope effects for each of 0.992–0.996 are consistent with a common mechanism involving hydride transfer from the uncharged amine. Computational analyses of possible mechanisms support this conclusion. Deuterium and solvent isotope effects with wild‐type and mutant variants of the lactate dehydrogenase flavocytochrome b~2~ show that OH and CH bond cleavage are not concerted, but become so in the Y254F enzyme. This is consistent with a highly asynchronous reaction in which OH bond cleavage precedes hydride transfer. The results of Hammett analyses and solvent and deuterium isotope effects support a similar mechanism for alcohol oxidase. Copyright Β© 2007 John Wiley & Sons, Ltd.

πŸ“œ SIMILAR VOLUMES

Insights into the mechanisms of action o
Insights into the mechanisms of action of host defence peptides from biophysical and structural investigations
✍ Burkhard Bechinger πŸ“‚ Article πŸ“… 2011 πŸ› John Wiley and Sons 🌐 English βš– 318 KB

## Abstract In order to better understand the mechanisms of action of linear cationic host defense peptides, biophysical and structural investigations of their interactions with membranes and with other biomacromolecules are reviewed. In particular, an extensive overview will be given of the topolo

Understanding the transition states of p
Understanding the transition states of phosphodiester bond cleavage: Insights from heavy atom isotope effects
✍ Adam G. Cassano; Vernon E. Anderson; Michael E. Harris πŸ“‚ Article πŸ“… 2003 πŸ› Wiley (John Wiley & Sons) 🌐 English βš– 175 KB πŸ‘ 2 views

## Abstract The nucleotides of DNA and RNA are joined by phosphodiester linkages whose synthesis and hydrolysis are catalyzed by numerous essential enzymes. Two prominent mechanisms have been proposed for RNA and protein enzyme catalyzed cleavage of phosphodiester bonds in RNA: (a) __intra__molecul