scholarly journals Linear enzyme cascade for the production of (–)-iso-isopulegol

2019 ◽  
Vol 74 (3-4) ◽  
pp. 63-70 ◽  
Author(s):  
Christin Peters ◽  
Rebecca Buller
Keyword(s):  
Cascade Reactions ◽  
Initial Reaction ◽  
Reaction Step ◽  
Isolation And Purification ◽  
Linear Cascade ◽  
Enzyme Cascade ◽  
Cosmetic Industry ◽  
Pure Compounds ◽  
Alicyclobacillus Acidocaldarius ◽  
Set Up

Abstract Biocatalysis has developed enormously in the last decade and now offers solutions for the sustainable production of chiral and highly functionalised asset molecules. Products generated by enzymatic transformations are already being used in the food, feed, chemical, pharmaceutical and cosmetic industry, and the accessible compound panoply is expected to expand even further. In particular, the combination of stereo-selective enzymes in linear cascade reactions is an elegant strategy toward enantiomeric pure compounds, as it reduces the number of isolation and purification steps and avoids accumulation of potentially unstable intermediates. Here, we present the set-up of an enzyme cascade to selectively convert citral to (–)-iso-isopulegol by combining an ene reductase and a squalene hopene cyclase. In the initial reaction step, the ene reductase YqjM from Bacillus subtilis selectively transforms citral to (S)-citronellal, which is subsequently cyclised exclusively to (–)-iso-isopulegol by a mutant of the squalene hopene cyclase from Alicyclobacillus acidocaldarius (AacSHC). With this approach, we can convert citral to an enantiopure precursor for isomenthol derivatives.

scholarly journals Microfluidics Featuring Multilayered Hydrogel Assemblies Enable Real-Time NMR-Monitoring of Enzyme Cascade Reactions

2020 ◽  
Author(s):  
Nurdiana Nordin ◽  
lorenzo bordonali ◽  
Hossein Davoodi ◽  
Novindi Dwi Ratnawati ◽  
Gudrun Gygli ◽  
...  
Keyword(s):  
Real Time ◽  
Functional Performance ◽  
Cascade Reactions ◽  
Inhibitory Effect ◽  
Resonance Spectroscopy ◽  
Reaction Cell ◽  
Enzyme Cascade ◽  
Sensing Applications ◽  
Progress Curve ◽  
Michaelis Constants

Compartmentalized chemical reactions at the microscale are interesting from many perspectives including (multi)functional surfaces and biotechnology. Monitoring the molecular content as a measure of functional performance at these small scales is challenging. As a means to address this challenge, we leverage microtechnology and biocompatible materials to integrate a compact, reconfigurable reaction cell featuring electrochemical functionality with high-resolution nuclear magnetic resonance spectroscopy (NMR). We demonstrate the operation of this system by monitoring the activity of enzymes immobilized in chemically distinct layers within a multi-layered chitosan hydrogel assembly. As a benchmark, we observed the parallel activities of urease (Urs), catalase (Cat), and glucose oxidase (GOx) by recording NMR spectra to extract reagent and product concentrations in real-time. As a result, simultaneous monitoring of a cooperative enzymatic process (GOx + Cat) together with an independent process (Urs) is achieved. Using Michaelis-Menten progress curve analysis of the NMR data, kinetic data is extracted: in the case of GOx, the Michaelis constants (K<sub>M</sub>) are consistent with previous reports, while for Urs, deviations are observed, attributed to an inhibitory effect under our reaction conditions. The system therefore enables the construction of complex reaction cascades with spatial control, as would be interesting in, for example, metabolic engineering and multiplexed sensing applications.

which challenges him into interpretative activity, into being a solver and realizer of the text rather than just a passive consumer of it. I have subjected the giraffe to such prolonged analysis because it is an emblematic beast. The point I want to stress in this paper is that Heliodoros’ whole novel demands an active interpretative response from his reader. The Aithioptka is a much more challen­ ging read than any of the other Greek novels, precisely because it is pervaded at every level by the kind of self-conscious game-playing typified by the riddle of the giraffe. Here, for instance, is the Egyptian priest, Kalasiris, who acts as narrator for about a third of the whole novel, describing a dream he had on the island of Zakynthos: as I slept, a vision of an old man appeared to me. Age had withered him almost to a skeleton, except that his cloak was hitched up to reveal a thigh that retained some vestige of the strength of his youth. He wore a leather helmet on his head, and his expression was one of cunning and many wiles; he was lame in one leg, as if from a wound of some kind. (5.22.1) The vision reproaches Kalasiris for failing even to pay him a visit while in the vicinity, prophesies punishment for the omission, but conveys greetings from his wife to Kalasiris’ charge, the heroine Charikleja, ‘since she esteems chastity above all things’ (5.22.3). Again a riddle is set up by not immediately identifying the old man, and again the description is presented from the point of view of a character within the story. Here, however, the situation is rather more complicated, since Kalasiris himself has two aspects, as narrator and character within his own narration. As narrator he knows the identity of the dream figure, but in his presentation of his own experience he omits any explanatory gloss, and re-enacts the perplexity of his initial reaction. He describes the dream as he saw it, rather than as he subsequently understood it. Again the reader is challenged to disambiguate the riddle by matching the points of the description with knowledge acquired elsewhere. Every detail corresponds to something in the Homeric poems.4 This time Heliodoros has succeeded in keeping the easiest clues to the end, particularly the formulaic epithet polytropos (‘of many wiles’), proverbially associated with one epic individual, and the reference to a wound in the leg which also clinches its owner’s recognition in the original. Further clues are offered by the fact

2014 ◽  
pp. 320-320
Keyword(s):  
Point Of View ◽  
The Other ◽  
Initial Reaction ◽  
Game Playing ◽  
Set Up ◽  
As If

Blue, White, and Red Heat

Boom Cities ◽  
2019 ◽  
pp. 35-63
Author(s):  
Otto Saumarez Smith
Keyword(s):  
Local Government ◽  
Central Government ◽  
Central Area ◽  
Public Private Partnerships ◽  
Initial Reaction ◽  
Local Authorities ◽  
Set Up ◽  
Area Redevelopment ◽  
Planning Group ◽  
City Centres

This chapter looks at central government’s role in directing the way in which local authorities enacted central-area redevelopment schemes. It shows how modernist ideas were sustained by a broadly consensual cross-party political culture in central government. It shows how the Joint Urban Planning Group, set up within the Ministry of Housing and Local Government, provided guidance to local authorities in how to form public–private partnerships to redevelop their city centres. The last section discusses the fate of these ideas during Labour’s first term after the 1964 election, and argues for an economic explanation of the initial reaction against modernist approaches to the built environment.

Multi‐enzyme Cascade Reactions in Metal‐organic Frameworks

2020 ◽  
Vol 20 (10) ◽  
pp. 1100-1116 ◽  
Author(s):  
Jieying Liang ◽  
Kang Liang
Keyword(s):  
Metal Organic Frameworks ◽  
Cascade Reactions ◽  
Enzyme Cascade ◽  
Metal Organic

scholarly journals Recent Advances in Enzymatic and Chemoenzymatic Cascade Processes

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1258
Author(s):  
Noelia Losada-Garcia ◽  
Zaida Cabrera ◽  
Paulina Urrutia ◽  
Carla Garcia-Sanz ◽  
Alicia Andreu ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Solid Phase ◽  
Cascade Reactions ◽  
Review Article ◽  
The Novel ◽  
Enzyme Cascade ◽  
Cascade Processes ◽  
Novel Strategy ◽  
Substantial Interest

Cascade reactions have been described as efficient and universal tools, and are of substantial interest in synthetic organic chemistry. This review article provides an overview of the novel and recent achievements in enzyme cascade processes catalyzed by multi-enzymatic or chemoenzymatic systems. The examples here selected collect the advances related to the application of the sequential use of enzymes in natural or genetically modified combination; second, the important combination of enzymes and metal complex systems, and finally we described the application of biocatalytic biohybrid systems on in situ catalytic solid-phase as a novel strategy. Examples of efficient and interesting enzymatic catalytic cascade processes in organic chemistry, in the production of important industrial products, such as the designing of novel biosensors or bio-chemocatalytic systems for medicinal chemistry application, are discussed

Enzyme cascade reactions: synthesis of furandicarboxylic acid (FDCA) and carboxylic acids using oxidases in tandem

2015 ◽  
Vol 17 (6) ◽  
pp. 3271-3275 ◽  
Author(s):  
Shane M. McKenna ◽  
Silke Leimkühler ◽  
Susanne Herter ◽  
Nicholas J. Turner ◽  
Andrew J. Carnell
Keyword(s):  
Carboxylic Acids ◽  
Cascade Reactions ◽  
Preparative Scale ◽  
Mild Conditions ◽  
Enzyme Cascade ◽  
Furandicarboxylic Acid

Three enzymes are combined under mild conditions for the preparative scale oxidation of HMF to FDCA and a range of 10 alcohols.

scholarly journals Multi-enzyme cascade reactions using protein–polymer surfactant self-standing films

2017 ◽  
Vol 53 (13) ◽  
pp. 2094-2097 ◽  
Author(s):  
Thomas Farrugia ◽  
Adam W. Perriman ◽  
Kamendra P. Sharma ◽  
Stephen Mann
Keyword(s):  
Cascade Reactions ◽  
Hierarchical Assembly ◽  
Protein Polymer ◽  
Enzyme Cascade ◽  
Catalytically Active ◽  
Polymer Surfactant

Self-supporting bio-catalytically active multi-enzyme films fabricated via hierarchical assembly of enzyme–polymer surfactant nanoconjugates are capable of sustaining cascade reactions.

Fusion proteins of an enoate reductase and a Baeyer-Villiger monooxygenase facilitate the synthesis of chiral lactones

2017 ◽  
Vol 398 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Christin Peters ◽  
Florian Rudroff ◽  
Marko D. Mihovilovic ◽  
Uwe T. Bornscheuer
Keyword(s):  
Fusion Protein ◽  
Fusion Proteins ◽  
Reaction Rates ◽  
Cascade Reactions ◽  
Product Formation ◽  
Similar Reaction ◽  
Enzyme Cascade ◽  
Enoate Reductase ◽  
Chiral Lactones

Abstract Nature uses the advantages of fusion proteins for multi-step reactions to facilitate the metabolism in cells as the conversion of substrates through intermediates to the final product can take place more rapidly and with less side-product formation. In a similar fashion, also for enzyme cascade reactions, the fusion of biocatalysts involved can be advantageous. In the present study, we investigated fusion of an alcohol dehydrogenase (ADH), an enoate reductase (ERED) and a Baeyer-Villiger monooxygenase (BVMO) to enable the synthesis of (chiral) lactones starting from unsaturated alcohols as substrates. The domain order and various linkers were studied to find optimal conditions with respect to expression levels and enzymatic activities. Best results were achieved for the ERED xenobiotic reductase B (XenB) from Pseudomonas putida and the cyclohexanone monooxygenase (CHMO) from Acinetobacter sp., whereas none of the ADHs studied could be fused successfully. This fusion protein together with separately supplied ADH resulted in similar reaction rates in in vivo biocatalysis reactions. After 1.5 h we could detect 40% more dihydrocarvone lactone in in vivo reactions with the fusion protein and ADH then with the single enzymes.

scholarly journals Encapsulated Hydrogels by E-beam Lithography and Their Use in Enzyme Cascade Reactions

Langmuir ◽  
2016 ◽  
Vol 32 (16) ◽  
pp. 4043-4051 ◽  
Author(s):  
Rock J. Mancini ◽  
Samantha J. Paluck ◽  
Erhan Bat ◽  
Heather D. Maynard
Keyword(s):  
Cascade Reactions ◽  
Enzyme Cascade
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