scholarly journals Enantioselective Epoxidation by Flavoprotein Monooxygenases Supported by Organic Solvents

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 568 ◽  
Author(s):  
Daniel Eggerichs ◽  
Carolin Mügge ◽  
Julia Mayweg ◽  
Ulf-Peter Apfel ◽  
Dirk Tischler
Keyword(s):  
Organic Solvents ◽  
Nicotinamide Adenine Dinucleotide ◽  
In Silico ◽  
Flavin Adenine Dinucleotide ◽  
Substrate Preference ◽  
Solvent Tolerance ◽  
Organic Cosolvents ◽  
Two Component ◽  
Enantioselective Epoxidation ◽  
Styrene Derivatives

Styrene and indole monooxygenases (SMO and IMO) are two-component flavoprotein monooxygenases composed of a nicotinamide adenine dinucleotide (NADH)-dependent flavin adenine dinucleotide (FAD)-reductase (StyB or IndB) and a monooxygenase (StyA or IndA). The latter uses reduced FAD to activate oxygen and to oxygenate the substrate while releasing water. We circumvented the need for the reductase by direct FAD reduction in solution using the NAD(P)H-mimic 1-benzyl-1,4-dihydronicotinamide (BNAH) to fuel monooxygenases without NADH requirement. Herein, we report on the hitherto unknown solvent tolerance for the indole monooxygenase from Gemmobacter nectariphilus DSM15620 (GnIndA) and the styrene monooxygenase from Gordonia rubripertincta CWB2 (GrStyA). These enzymes were shown to convert bulky and rather hydrophobic styrene derivatives in the presence of organic cosolvents. Subsequently, BNAH-driven biotransformation was furthermore optimized with regard to the applied cosolvent and its concentration as well as FAD and BNAH concentration. We herein demonstrate that GnIndA and GrStyA enable selective epoxidations of allylic double bonds (up to 217 mU mg−1) in the presence of organic solvents such as tetrahydrofuran, acetonitrile, or several alcohols. Notably, GnIndA was found to resist methanol concentrations up to 25 vol.%. Furthermore, a diverse substrate preference was determined for both enzymes, making their distinct use very interesting. In general, our results seem representative for many IMOs as was corroborated by in silico mutagenetic studies.

scholarly journals Thermodynamic, Computational Solubility Parameters in Organic Solvents and In Silico GastroPlus Based Prediction of Ketoconazole

ACS Omega ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 5033-5045
Author(s):  
Sultan Alshehri ◽  
Afzal Hussain ◽  
Mohd Neyaz Ahsan ◽  
Raisuddin Ali ◽  
Mohd Usman Mohd Siddique
Keyword(s):  
Organic Solvents ◽  
In Silico ◽  
Solubility Parameters

Thermal Desorption Efficiencies of Two-Component Organic Solvents from Activated Carbon

AIHAJ ◽  
1989 ◽  
Vol 50 (1) ◽  
pp. 24-29 ◽  
Author(s):  
HAJIME HORI ◽  
ISAMU TANAKA ◽  
TAKASHI AKIYAMA
Keyword(s):  
Activated Carbon ◽  
Organic Solvents ◽  
Thermal Desorption ◽  
Two Component

scholarly journals A Regulatory Role of NAD Redox Status on Flavin Cofactor Homeostasis inS. cerevisiaeMitochondria

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Teresa Anna Giancaspero ◽  
Vittoria Locato ◽  
Maria Barile
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nicotinamide Adenine Dinucleotide ◽  
Flavin Adenine Dinucleotide ◽  
Redox Balance ◽  
Redox Status ◽  
Cellular Redox ◽  
Isolated Mitochondria ◽  
Nudix Hydrolases ◽  
Order Of Magnitude

Flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NAD) are two redox cofactors of pivotal importance for mitochondrial functionality and cellular redox balance. Despite their relevance, the mechanism by which intramitochondrial NAD(H) and FAD levels are maintained remains quite unclear inSaccharomyces cerevisiae. We investigated here the ability of isolated mitochondria to degrade externally added FAD and NAD (in both its reduced and oxidized forms). A set of kinetic experiments demonstrated that mitochondrial FAD and NAD(H) destroying enzymes are different from each other and from the already characterized NUDIX hydrolases. We studied here, in some detail, FAD pyrophosphatase (EC 3.6.1.18), which is inhibited by NAD+and NADH according to a noncompetitive inhibition, withKivalues that differ from each other by an order of magnitude. These findings, together with the ability of mitochondrial FAD pyrophosphatase to metabolize endogenous FAD, presumably deriving from mitochondrial holoflavoproteins destined to degradation, allow for proposing a novel possible role of mitochondrial NAD redox status in regulating FAD homeostasis and/or flavoprotein degradation inS. cerevisiae.

Enantioselective epoxidation of styrene derivatives by chloroperoxidase catalysis

1993 ◽  
Vol 4 (6) ◽  
pp. 1325-1330 ◽  
Author(s):  
Stefano Colonna ◽  
Nicoletta Gaggero ◽  
Luigi Casella ◽  
Giacomo Carrea ◽  
Piero Pasta
Keyword(s):  
Enantioselective Epoxidation ◽  
Styrene Derivatives

scholarly journals Gene mining, codon optimization and analysis of binding mechanism of an aldo-keto reductase with high activity, better substrate specificity and excellent solvent tolerance

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260787
Author(s):  
Wei Jiang ◽  
Xiaoli Fu ◽  
Weiliang Wu
Keyword(s):  
High Activity ◽  
Organic Solvents ◽  
Catalytic Reduction ◽  
Antidepressant Drug ◽  
Reaction System ◽  
Solvent Tolerance ◽  
Chiral Alcohols ◽  
Binding Mechanism ◽  
Potential Applications ◽  
Mediated Reduction

The biosynthesis of chiral alcohols has important value and high attention. Aldo–keto reductases (AKRs) mediated reduction of prochiral carbonyl compounds is an interesting way of synthesizing single enantiomers of chiral alcohols due to the high enantio-, chemo- and regioselectivity of the enzymes. However, relatively little research has been done on characterization and apply of AKRs to asymmetric synthesis of chiral alcohols. In this study, the AKR from Candida tropicalis MYA-3404 (C. tropicalis MYA-3404), was mined and characterized. The AKR shown wider optimum temperature and pH. The AKR exhibited varying degrees of catalytic activity for different substrates, suggesting that the AKR can catalyze a variety of substrates. It is worth mentioning that the AKR could catalytic reduction of keto compounds with benzene rings, such as cetophenone and phenoxyacetone. The AKR exhibited activity on N,N-dimethyl-3-keto-3-(2-thienyl)-1-propanamine (DKTP), a key intermediate for biosynthesis of the antidepressant drug duloxetine. Besides, the AKR still has high activity whether in a reaction system containing 10%-30% V/V organic solvent. What’s more, the AKR showed the strongest stability in six common organic solvents, DMSO, acetonitrile, ethyl acetate, isopropanol, ethanol, and methanol. And, it retains more that 70% enzyme activity after 6 hours, suggesting that the AKR has strong solvent tolerance. Furthermore, the protein sequences of the AKR and its homology were compared, and a 3D model of the AKR docking with coenzyme NADPH were constructed. And the important catalytic and binding sites were identified to explore the binding mechanism of the enzyme and its coenzyme. These properties, predominant organic solvents resistance and extensive substrate spectrum, of the AKR making it has potential applications in the pharmaceutical field.

scholarly journals Highly Efficient Synthesis of 2,5-Dihydroxypyridine using Pseudomonas sp. ZZ-5 Nicotine Hydroxylase Immobilized on Immobead 150

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 548 ◽  
Author(s):  
Caiwen Dong ◽  
Yadong Zheng ◽  
Hongzhi Tang ◽  
Zhangde Long ◽  
Jigang Li ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Flavin Adenine Dinucleotide ◽  
Immobilized Enzymes ◽  
Enzyme Concentration ◽  
Pseudomonas Sp ◽  
Optimal Conditions ◽  
Efficient Synthesis ◽  
Protein Loading ◽  
Reaction Cycles ◽  
Hydrolysis Of

In this report, the use of immobilized nicotine hydroxylase from Pseudomonas sp. ZZ-5 (HSPHZZ) for the production of 2,5-dihydroxypyridine (2,5-DHP) from 6-hydroxy-3-succinoylpyridine (HSP) in the presence of nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) is described. HSPHZZ was covalently immobilized on Immobead 150 (ImmHSPHZZ). ImmHSPHZZ (obtained with 5–30 mg of protein per gram of support) catalyzed the hydrolysis of HSP to 2,5-DHP. At a protein loading of 15 mg g−1, ImmHSPHZZ converted 93.6% of HSP to 2,5-DHP in 6 h. The activity of ImmHSPHZZ was compared with that of free HSPHZZ under various conditions, including pH, temperature, enzyme concentration, substrate concentration and stability over time, and kinetic parameters were measured. The results showed that ImmHSPHZZ performed better over wider ranges of pH and temperature when compared with that of HSPHZZ. The optimal concentrations of ImmHSPHZZ and substrate were 30 mg L−1 and 0.75 mM, respectively. Under optimal conditions, 94.5 mg L−1 of 2,5-DHP was produced after 30 min with 85.4% conversion. After 8 reaction cycles and 6 days of storage, 51.3% and 75.0% of the initial enzyme activity remained, respectively. The results provide a framework for development of commercially suitable immobilized enzymes that produce 2,5-DHP.

Amorphous Silicon Photosensors for Detection of Intrinsic Cell Fluorophores

2011 ◽  
Vol 1321 ◽  
Author(s):  
A. Joskowiak ◽  
V. Chu ◽  
D.M.F. Prazeres ◽  
J.P. Conde
Keyword(s):  
Carbon Content ◽  
Amorphous Silicon ◽  
Nicotinamide Adenine Dinucleotide ◽  
Redox State ◽  
Flavin Adenine Dinucleotide ◽  
Cutoff Wavelength ◽  
Silicon Carbon ◽  
Intrinsic Fluorophores ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
High Pass

ABSTRACTAn amorphous silicon (a-Si:H) photoconductor array with two distinct integrated amorphous silicon carbon alloy (a-SiC:H) high pass filters is used to detect two of the cell intrinsic fluorophores. The cutoff wavelength of the filters is tuned by the carbon content in the film. The fluorophores of interest – reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are indicative of the redox state of the cells. Concentrations down to 1 μM for NADH and 50 μM for FAD were detected.

scholarly journals Characterization and Catalytic-Site-Analysis of an Aldo-Keto Reductase with Excellent Solvent Tolerance

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1121
Author(s):  
Rui Pei ◽  
Weiliang Wu ◽  
Yuqian Zhang ◽  
Libing Tian ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Reaction System ◽  
Catalytic Site ◽  
Solvent Tolerance ◽  
Chiral Alcohols ◽  
High Catalytic Activity ◽  
Site Analysis ◽  
Substrate Spectrum

Aldo-keto reductases (AKRs) mediated stereoselective reduction of prochiral carbonyl compounds is an efficient way of preparing single enantiomers of chiral alcohols due to their high chemo-, enantio-, and regio-selectivity. To date, the application of AKRs in the asymmetric synthesis of chiral alcohols has been limited, due to the challenges of cloning and purifying. In this work, the aldo-keto reductase (AKR3-2-9) from Bacillus sp. was obtained, purified and proved to be NADPH-dependent. It exhibits good bioactivity and stability at 37 °C, pH 6.0. AKR3-2-9 is catalytically active on 11 pairs of substrates such as 3-methylcyclohexanone and methyl pyruvate, among which it showed the highest catalytic activity for acetylacetone. In addition, AKR3-2-9 was able to be resistant to five common organic solvents such as methanol and ethanol, it retained high catalytic activity even in a reaction system containing 10% v/v organic solvent for 6 h, which indicates its broad substrate spectrum and exceptional organic solvent tolerance. Furthermore, its three-dimensional structure was constructed and catalytic-site-analysis of the enzyme was conducted. Notably, it was capable of catalyzing the reaction of the key intermediates of duloxetine. The extensive substrate spectrum and predominant organic solvents resistance makes AK3-2-9 a promising enzyme which can be potentially applied in medicine synthesis.

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