Old Yellow Enzyme (old + yellow_enzyme)

Distribution by Scientific Domains


Selected Abstracts


Computational studies of electron-transfer processes in old yellow enzyme

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 6 2001
Ginger M. Chateauneuf
Abstract Old Yellow Enzyme (OYE) is a flavoenzyme that was first isolated from brewer's bottom yeast. Homologues have been identified in other strains of yeast, bacteria, and plants. In plants, the OYE homologue functions enzymatically in the synthesis of plant hormones, but the biological function of OYE in yeast is still unknown. Flavin mononucleotide (FMN) is the cofactor that is noncovalently bound in the enzyme. OYE binds several phenolic ligands that serve as models for reactive biological substrates. These complexes have broad long-wavelength absorption bands, which have been ascribed to charge-transfer interactions, with the phenolate anion acting as the electron donor and the FMN as the acceptor [Abramovitz, A. S.; Massey, V. J Bio Chem 1976, 251, 5327,5336]. The computational characterization of these electronic transitions in the active site will help in understanding the biological processes in the enzyme. It was found that at several levels of computational methods, and through computationally mutating relevant amino acids, a charge-transfer process is occurring. This result agrees with previous experimental work and is consistent with all ultraviolet,visible spectrophotometric data. The preliminary results for the computational studies of these electron-transfer processes will be presented. 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 [source]


The Substrate Spectra of Pentaerythritol Tetranitrate Reductase, Morphinone Reductase, N -Ethylmaleimide Reductase and Estrogen-Binding Protein in the Asymmetric Bioreduction of Activated Alkenes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010
Nicole
Abstract Four flavoproteins from the old yellow enzyme (OYE) family, pentaerythritol tetranitrate (PETNR) reductase, N -ethylmaleimide reductase (NEMR), morphinone reductase (MorR) and estrogen-binding protein (EBP1), exhibited a broad substrate tolerance by accepting conjugated enals, enones, imides, dicarboxylic acids and esters, as well as a nitroalkene and therefore can be employed for the asymmetric bioreduction of carbon-carbon double (CC) bonds. In particular, morphinone reductase and estrogen-binding protein often showed a complementary stereochemical preference in comparison to that of previously investigated OYEs. [source]


Computational studies of electron-transfer processes in old yellow enzyme

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 6 2001
Ginger M. Chateauneuf
Abstract Old Yellow Enzyme (OYE) is a flavoenzyme that was first isolated from brewer's bottom yeast. Homologues have been identified in other strains of yeast, bacteria, and plants. In plants, the OYE homologue functions enzymatically in the synthesis of plant hormones, but the biological function of OYE in yeast is still unknown. Flavin mononucleotide (FMN) is the cofactor that is noncovalently bound in the enzyme. OYE binds several phenolic ligands that serve as models for reactive biological substrates. These complexes have broad long-wavelength absorption bands, which have been ascribed to charge-transfer interactions, with the phenolate anion acting as the electron donor and the FMN as the acceptor [Abramovitz, A. S.; Massey, V. J Bio Chem 1976, 251, 5327,5336]. The computational characterization of these electronic transitions in the active site will help in understanding the biological processes in the enzyme. It was found that at several levels of computational methods, and through computationally mutating relevant amino acids, a charge-transfer process is occurring. This result agrees with previous experimental work and is consistent with all ultraviolet,visible spectrophotometric data. The preliminary results for the computational studies of these electron-transfer processes will be presented. 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 [source]


Towards structural studies of the old yellow enzyme homologue SYE4 from Shewanella oneidensis and its complexes at atomic resolution

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010
Jonathan Elegheert
Shewanella oneidensis is an environmentally versatile Gram-negative ,-proteobacterium that is endowed with an unusually large proteome of redox proteins. Of the four old yellow enzyme (OYE) homologues found in S. oneidensis, SYE4 is the homologue most implicated in resistance to oxidative stress. SYE4 was recombinantly expressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to the orthorhombic space group P212121 and were moderately pseudo-merohedrally twinned, emulating a P422 metric symmetry. The native crystals of SYE4 were of exceptional diffraction quality and provided complete data to 1.10, resolution using synchrotron radiation, while crystals of the reduced enzyme and of the enzyme in complex with a wide range of ligands typically led to high-quality complete data sets to 1.30,1.60, resolution, thus providing a rare opportunity to dissect the structure,function relationships of a good-sized enzyme (40,kDa) at true atomic resolution. Here, the attainment of a number of experimental milestones in the crystallographic studies of SYE4 and its complexes are reported, including isolation of the elusive hydride,Meisenheimer complex. [source]