scholarly journals Nature of the Reaction Intermediates in the Flavin Adenine Dinucleotide-Dependent Epoxidation Mechanism of Styrene Monooxygenase

Biochemistry ◽  
2011 ◽  
Vol 50 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Auric Kantz ◽  
George T. Gassner
Keyword(s):  
Flavin Adenine Dinucleotide ◽  
Reaction Intermediates ◽  
Styrene Monooxygenase

scholarly journals Photoenzymatic epoxidation of styrenes

2019 ◽  
Vol 55 (12) ◽  
pp. 1790-1792 ◽  
Author(s):  
Morten M. C. H. van Schie ◽  
Caroline E. Paul ◽  
Isabel W. C. E. Arends ◽  
Frank Hollmann
Keyword(s):  
Flavin Adenine Dinucleotide ◽  
Photochemical Reduction ◽  
Styrene Monooxygenase

Photochemical reduction of flavin adenine dinucleotide (FAD) enables the direct, non-enzymatic regeneration of styrene monooxygenase for enantiospecific epoxidation reactions.

scholarly journals Bacterial degradation of styrene involving a novel flavin adenine dinucleotide-dependent styrene monooxygenase.

1990 ◽  
Vol 56 (5) ◽  
pp. 1347-1351 ◽  
Author(s):  
S Hartmans ◽  
M J van der Werf ◽  
J A de Bont
Keyword(s):  
Flavin Adenine Dinucleotide ◽  
Bacterial Degradation ◽  
Styrene Monooxygenase

Analyzing reactions of single mechanoenzyme molecules by light microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 426-427
Author(s):  
Jeff Gelles
Keyword(s):  
Image Processing ◽  
Reaction Mechanisms ◽  
Transient State ◽  
Nanometer Scale ◽  
Reaction Intermediates ◽  
Enzyme Molecule ◽  
Directed Movement ◽  
Enzyme Molecules ◽  
Individual Enzyme ◽  
Single Reaction

Mechanoenzymes are enzymes which use a chemical reaction to power directed movement along biological polymer. Such enzymes include the cytoskeletal motors (e.g., myosins, dyneins, and kinesins) as well as nucleic acid polymerases and helicases. A single catalytic turnover of a mechanoenzyme moves the enzyme molecule along the polymer a distance on the order of 10−9 m We have developed light microscope and digital image processing methods to detect and measure nanometer-scale motions driven by single mechanoenzyme molecules. These techniques enable one to monitor the occurrence of single reaction steps and to measure the lifetimes of reaction intermediates in individual enzyme molecules. This information can be used to elucidate reaction mechanisms and determine microscopic rate constants. Such an approach circumvents difficulties encountered in the use of traditional transient-state kinetics techniques to examine mechanoenzyme reaction mechanisms.

Lateral Adsorbate Interactions Inhibit HCOO- While Promoting CO Selectivity for CO2 Electrocatalysis on Ag

2018 ◽  
Author(s):  
Divya Bohra ◽  
Isis Ledezma-Yanez ◽  
Guanna Li ◽  
Wiebren De Jong ◽  
Evgeny A. Pidko ◽  
...  
Keyword(s):  
Electrochemical Reduction ◽  
Experimental Approach ◽  
Decisive Role ◽  
Experimental Methods ◽  
Reaction Intermediates ◽  
Intermediate Species ◽  
Experimental Knowledge ◽  
Complex Interactions ◽  
Ag Catalysts

<p>The analysis presented in this manuscript helps bridge an important fundamental discrepancy between the existing theoretical and experimental knowledge regarding the performance of Ag catalysts for CO<sub>2</sub> electrochemical reduction (CO<sub>2</sub>ER). The results demonstrate how the intermediate species *OCHO is formed readily en-route the HCOO<sup>– </sup>pathway and plays a decisive role in determining selectivity of a predominantly CO producing catalyst such as Ag. Our theoretical and experimental approach develops a better understanding of the nature of competition as well as the complex interactions between the reaction intermediates leading to CO, HCOO<sup>–</sup> and H<sub>2</sub> during CO<sub>2</sub>ER.</p><p><br></p><p>Details of computational and experimental methods are present in the Supporting Information provided. </p><p><br></p><p><br></p>

scholarly journals Flavin Adenine Dinucleotide-Dependent Halogenase XanH and Engineering of Multifunctional Fusion Halogenases

2020 ◽  
Vol 86 (18) ◽  
Author(s):  
Lingxin Kong ◽  
Qing Wang ◽  
Zixin Deng ◽  
Delin You
Keyword(s):  
Protein Engineering ◽  
Fusion Protein ◽  
Natural Product ◽  
Flavin Adenine Dinucleotide ◽  
High Efficiency ◽  
Genetic Manipulation ◽  
Good Alternative ◽  
Limited Information ◽  
Flavin Reductase ◽  
Free Standing

ABSTRACT Xantholipin (compound 1), a polycyclic xanthone antibiotic, exhibited strong antibacterial activities and showed potent cytotoxicity. The biosynthetic gene cluster of compound 1 has been identified in our previous work, and the construction of xanthone nucleus has been well demonstrated. However, limited information of the halogenation involved in compound 1 biosynthesis is available. In this study, based on the genetic manipulation and biochemical assay, we characterized XanH as an indispensable flavin adenine dinucleotide (FAD)-dependent halogenase (FDH) for the biosynthesis of compound 1. XanH was found to be a bifunctional protein capable of flavin reduction and chlorination and exclusively used the NADH. However, the reduced flavin could not be fully and effectively utilized, and the presence of an extra flavin reductase (FDR) and chemical-reducing agent could promote the halogenation. XanH accepted its natural free-standing substrate with angular fused polycyclic aromatic systems. Meanwhile, it exhibited moderate halogenation activity and possessed high substrate specificity. The requirement of extra FDR for higher halogenation activity is tedious for future engineering. To facilitate efforts in engineering XanH derivative proteins, we constructed the self-sufficient FDR-XanH fusion proteins. The fusion protein E1 with comparable activities to that of XanH could be used as a good alternative for future protein engineering. Taken together, these findings reported here not only improve the understanding of polycyclic xanthones biosynthesis but also expand the substrate scope of FDH and pave the way for future engineering of biocatalysts for new active substance synthesis. IMPORTANCE Halogenation is important in medicinal chemistry and plays an essential role in the biosynthesis of active secondary metabolites. Halogenases have evolved to catalyze reactions with high efficiency and selectivity, and engineering efforts have been made to engage the selective reactivity in natural product biosynthesis. The enzymatic halogenations are an environmentally friendly approach with high regio- and stereoselectivity, which make it a potential complement to organic synthesis. FDHs constitute one of the most extensively elucidated class of halogenases; however, the inventory awaits to be expanded for biotechnology applications and for the generation of halogenated natural product analogues. In this study, XanH was found to reduce flavin and halogenated the freely diffusing natural substrate with an angular fused hexacyclic scaffold, findings which were different from those for the exclusively studied FDHs. Moreover, the FDR-XanH fusion protein E1 with comparable reactivity to that of XanH serves as a successful example of genetic fusions and sets an important stage for future protein engineering.

scholarly journals Photoinactivation of Porcine d-Amino Acid Oxidase with Flavin Adenine Dinucleotide

1973 ◽  
Vol 248 (18) ◽  
pp. 6339-6347
Author(s):  
Shiao-Chun Tu ◽  
Donald B. McCormick
Keyword(s):  
Amino Acid ◽  
Flavin Adenine Dinucleotide ◽  
Acid Oxidase ◽  
Amino Acid Oxidase
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