scholarly journals LyGo: A platform for rapid screening of lytic polysaccharide monooxygenase production

2020 ◽  
Author(s):  
Cristina Hernández-Rollán ◽  
Kristoffer B. Falkenberg ◽  
Maja Rennig ◽  
Andreas B. Bertelsen ◽  
Johan Ø. Ipsen ◽  
...  

AbstractEnvironmentally friendly sources of energy and chemicals are essential constituents of a sustainable society. An important step towards this goal is the utilization of non-edible biomass as supply of building blocks for future biorefineries. Lytic polysaccharide monooxygenases (LPMOs) are enzymes that play a critical role in breaking the chemical bonds in the most abundant polymers found in recalcitrant biomass, such as cellulose and chitin. Predicting optimal strategies for producing LPMOs is often non-trivial, and methods allowing for screening several strategies simultaneously are therefore needed. Here, we present a standardized platform for cloning LPMOs. The platform allows users to combine gene fragments with different expression vectors in a simple 15-minute reaction, thus enabling rapid exploration of several gene contexts, hosts and expression strategies in parallel. The open-source LyGo platform is accompanied by easy-to-follow online protocols for both cloning and expression. As a demonstration, we utilize the LyGo platform to explore different strategies for expressing several different LPMOs in Escherichia coli, Bacillus subtilis, and Komagataella phaffii.

2021 ◽  
Vol 9 ◽  
Author(s):  
Damao Wang ◽  
Yanping Li ◽  
Yuting Zheng ◽  
Yves S. Y. Hsieh

Lytic polysaccharide monooxygenase (LPMO) is a newly discovered and widely studied enzyme in recent years. These enzymes play a key role in the depolymerization of sugar-based biopolymers (including cellulose, hemicellulose, chitin and starch), and have a positive significance for biomass conversion. LPMO is a copper-dependent enzyme that can oxidize and cleave glycosidic bonds in cellulose and other polysaccharides. Their mechanism of action depends on the correct coordination of copper ions in the active site. There are still difficulties in the analysis of LPMO activity, which often requires multiple methods to be used in concert. In this review, we discussed various LPMO activity analysis methods reported so far, including mature mass spectrometry, chromatography, labeling, and indirect measurements, and summarized the advantages, disadvantages and applicability of different methods.


2018 ◽  
Vol 294 (5) ◽  
pp. 1516-1528 ◽  
Author(s):  
Silja Kuusk ◽  
Riin Kont ◽  
Piret Kuusk ◽  
Agnes Heering ◽  
Morten Sørlie ◽  
...  

Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes that catalyze oxidative cleavage of glycosidic bonds in polysaccharides in the presence of an external electron donor (reductant). In the classical O2-driven monooxygenase reaction, the reductant is needed in stoichiometric amounts. In a recently discovered, more efficient H2O2-driven reaction, the reductant would be needed only for the initial reduction (priming) of the LPMO to its catalytically active Cu(I) form. However, the influence of the reductant on reducing the LPMO or on H2O2 production in the reaction remains undefined. Here, we conducted a detailed kinetic characterization to investigate how the reductant affects H2O2-driven degradation of 14C-labeled chitin by a bacterial LPMO, SmLPMO10A (formerly CBP21). Sensitive detection of 14C-labeled products and careful experimental set-ups enabled discrimination between the effects of the reductant on LPMO priming and other effects, in particular enzyme-independent production of H2O2 through reactions with O2. When supplied with H2O2, SmLPMO10A catalyzed 18 oxidative cleavages per molecule of ascorbic acid, suggesting a “priming reduction” reaction. The dependence of initial rates of chitin degradation on reductant concentration followed hyperbolic saturation kinetics, and differences between the reductants were manifested in large variations in their half-saturating concentrations (KmRapp). Theoretical analyses revealed that KmRapp decreases with a decreasing rate of polysaccharide-independent LPMO reoxidation (by either O2 or H2O2). We conclude that the efficiency of LPMO priming depends on the relative contributions of reductant reactivity, on the LPMO's polysaccharide monooxygenase/peroxygenase and reductant oxidase/peroxidase activities, and on reaction conditions, such as O2, H2O2, and polysaccharide concentrations.


2019 ◽  
Vol 21 (21) ◽  
pp. 5924-5933 ◽  
Author(s):  
Salla Koskela ◽  
Shennan Wang ◽  
Dingfeng Xu ◽  
Xuan Yang ◽  
Kai Li ◽  
...  

An environmentally friendly, energy-efficient method for cellulose nanofibre (CNF) production from softwood holocellulose utilising oxidative enzymes, lytic polysaccharide monooxygenases (LPMOs).


2021 ◽  
Vol 12 (1) ◽  
pp. 352-362
Author(s):  
Aina McEvoy ◽  
Joel Creutzberg ◽  
Raushan K. Singh ◽  
Morten J. Bjerrum ◽  
Erik D. Hedegård

With QM/MM, we investigate the mechanism of tyrosine deprotonation in lytic polysaccharide monooxygenases. Our results support deprotonation and our calculated UV-vis spectra show that two isomers must be formed to match recent experiments.


2020 ◽  
Author(s):  
Bjørge Westereng ◽  
Stjepan K. Kračun ◽  
Shaun Leivers ◽  
Magnus Ø. Arntzen ◽  
Finn L. Aachmann ◽  
...  

ABSTRACTPolysaccharides from plant biomass are the most abundant renewable chemicals on Earth and can potentially be converted to a wide variety of useful glycoconjugates. While anomeric hydroxyl groups of carbohydrates are amenable to a variety of useful chemical modifications, selective cross-coupling to non-reducing ends has remained challenging. Several lytic polysaccharide monooxygenases (LPMOs), powerful enzymes known for their application in cellulose degradation, specifically oxidize non-reducing ends, introducing carbonyl groups that can be utilized for chemical coupling. This study provides a simple and highly specific approach to produce oxime-based glycoconjugates from LPMO-functionalized oligosaccharides. The products are evaluated by HPLC, mass spectrometry and NMR. Furthermore, we demonstrate potential biodegradability of these glycoconjugates using selective enzymes.


2019 ◽  
Vol 10 (2) ◽  
pp. 576-586 ◽  
Author(s):  
Octav Caldararu ◽  
Esko Oksanen ◽  
Ulf Ryde ◽  
Erik D. Hedegård

A mechanism for the formation of hydrogen peroxide by lytic polysaccharide monooxygenases (LPMOs) in the absence of substrate is proposed.


2020 ◽  
Vol 12 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Caio de Oliveira Gorgulho Silva ◽  
Tallyta Santos Teixeira ◽  
Kelly Barreto Rodrigues ◽  
Amanda Araújo Souza ◽  
Antonielle Vieira Monclaro ◽  
...  

Two new mass spectrometry methods, MALDI-TOF MS and hydrophilic interaction UHPLC-ESI-MS, were developed for the characterization of cellulose-active lytic polysaccharide monooxygenases, expanding the analytical toolbox for the study of these enzymes.


Author(s):  
Cristina Hernández-Rollán ◽  
Kristoffer B. Falkenberg ◽  
Maja Rennig ◽  
Andreas B. Bertelsen ◽  
Johan Ø. Ipsen ◽  
...  

Amylase ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Sebastian J. Muderspach ◽  
Tobias Tandrup ◽  
Kristian E. H. Frandsen ◽  
Gianluca Santoni ◽  
Jens-Christian N. Poulsen ◽  
...  

Abstract Lytic polysaccharide monooxygenases (LPMOs) are recently discovered copper enzymes that cleave recalcitrant polysaccharides by oxidation. The structure of an Aspergillus oryzae LPMO from the starch degrading family AA13 (AoAA13) has previously been determined from an orthorhombic crystal grown in the presence of copper, which is photoreduced in the structure. Here we describe how crystals reliably grown in presence of Zn can be Cu-loaded post crystallization. A partly photoreduced structure was obtained by severely limiting the X-ray dose, showing that this LPMO is much more prone to photoreduction than others. A serial synchrotron crystallography structure was also obtained, showing that this technique may be promising for further studies, to reduce even further photoreduction. We additionally present a triclinic structure of AoAA13, which has less occluded ligand binding site than the orthorhombic one. The availability of the triclinic crystals prompted new ligand binding studies, which lead us to the conclusion that small starch analogues do not bind to AoAA13 to an appreciable extent. A number of disordered conformations of the metal binding histidine brace have been encountered in this and other studies, and we have previously hypothesized that this disorder may be a consequence of loss of copper. We performed molecular dynamics in the absence of active site metal, and showed that the dynamics in solution differ somewhat from the disorder observed in the crystal, though the extent is equally dramatic.


2019 ◽  
Author(s):  
Raushan K. Singh ◽  
Bart v. Oort ◽  
Benedikt Möllers ◽  
David A. Russo ◽  
Ranjitha Singh ◽  
...  

AbstractLytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes capable of oxidizing crystalline cellulose and the enzyme has large practical application in the process of refining biomass. The LPMO catalytic mechanism still remains debated despite several proposed reaction mechanisms. Here, we report a long-lived intermediate (t½= 6 – 8 minutes) observed in an LPMO fromThermoascus aurantiacus(TaLPMO9A). The intermediate with a strong absorption around 420 nm is formed when reduced LPMO-Cu(I) reacts with H2O2. UV-vis absorption spectroscopy, electron paramagnetic resonance (EPR), and stopped-flow spectroscopy indicate that the observed long-lived intermediate involves the copper center and a nearby tyrosine (Tyr175). We propose that the reaction with H2O2first forms a highly reactive short-lived Cu(III)-intermediate which is subsequently transformed into the observed long-lived copper-dependent intermediate. Since sub-equimolar amount of H2O2to LPMO boosts oxidation of phosphoric acid swollen cellulose (PASC) suggests that the long-lived copper-dependent intermediate is part of the catalytic mechanism for LPMOs. The proposed mechanism offers new perspectives in the oxidative reaction mechanism of copper enzymes and hence for the biomass oxidation and the reactivity of copper in biological systems.


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