scholarly journals Efficient Degradation of Alginate And Preparation of Unsaturated Monosaccharides By A Novel Alginate Lyase And Effects of Domain Truncation On Biochemical Characteristics, Degradation Patterns

2021 ◽  
Author(s):  
Qian Li ◽  
Shengsheng Cao ◽  
Ling Zheng ◽  
Benwei Zhu
Keyword(s):  
Synergistic Effect ◽  
Brown Algae ◽  
Catalytic Efficiency ◽  
Alginate Lyase ◽  
Commercial Application ◽  
Action Mode ◽  
Domain Truncation ◽  
High Conversion Rate ◽  
Modular Domain ◽  
Alginate Lyases

Abstract BackgroundBrown algae are considered promising crops for the production of sustainable biofuels. However, its commercial application has been limited by lack of efficient methods for converting alginate into fermentable sugars. Recently, exo-type alginate lyases have received extensive attention due to their excellent ability of conversion of alginate into 4-deoxy-L-erythro-5-hexoseulose uronate (DEH), a promising material for bioethanol production and biorefinery systems.ResultsHerein, we cloned and characterized a novel alginate lyase AlyPL17 from Pedobacter hainanensis NJ-02. It possessed outstanding catalytic efficiency towards polymannuronic acid (polyM), polyguluronic acid (polyG) and alginate sodium, with kcat of 39.42 + 1.9 s-1, 32.53 + 0.88 s-1, and 38.30 + 2.12 s-1, respectively. In addition, AlyPL17 adopts a unique hybrid action mode to degrade alginate by the synergistic effect of two domains. Furthermore, the combination of AlyPL17 and AlyPL6 exhibited apparently synergistic effect for the preparation of unsaturated monosaccharides. ConclusionOverall, the results show that AlyPL17 is a PL17 exo-type alginate lyase with high activity and a high conversion rate at low/moderate temperatures, which provides a useful enzymatic tool for the conversion of brown algae into biofuels and enhance our understanding of the function of modular domain of alginate lyase.

scholarly journals Structure Characteristics, Biochemical Properties, and Pharmaceutical Applications of Alginate Lyases

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 628
Author(s):  
Shu-Kun Gao ◽  
Rui Yin ◽  
Xiao-Chen Wang ◽  
Hui-Ning Jiang ◽  
Xiao-Xiao Liu ◽  
...  
Keyword(s):  
Brown Algae ◽  
Catalytic Mechanism ◽  
Degradation Products ◽  
Structural Characteristics ◽  
Catalytic Efficiency ◽  
Alginate Lyase ◽  
Biochemical Properties ◽  
Structure And Property ◽  
Alginate Oligosaccharides ◽  
Alginate Lyases

Alginate, the most abundant polysaccharides of brown algae, consists of various proportions of uronic acid epimers α-L-guluronic acid (G) and β-D-mannuronic acid (M). Alginate oligosaccharides (AOs), the degradation products of alginates, exhibit excellent bioactivities and a great potential for broad applications in pharmaceutical fields. Alginate lyases can degrade alginate to functional AOs with unsaturated bonds or monosaccharides, which can facilitate the biorefinery of brown algae. On account of the increasing applications of AOs and biorefinery of brown algae, there is a scientific need to explore the important aspects of alginate lyase, such as catalytic mechanism, structure, and property. This review covers fundamental aspects and recent developments in basic information, structural characteristics, the structure–substrate specificity or catalytic efficiency relationship, property, molecular modification, and applications. To meet the needs of biorefinery systems of a broad array of biochemical products, alginate lyases with special properties, such as salt-activated, wide pH adaptation range, and cold adaptation are outlined. Withal, various challenges in alginate lyase research are traced out, and future directions, specifically on the molecular biology part of alginate lyases, are delineated to further widen the horizon of these exceptional alginate lyases.

scholarly journals Biochemical Characteristics and Variable Alginate-Degrading Modes of a Novel Bifunctional Endolytic Alginate Lyase

2017 ◽  
Vol 83 (23) ◽  
Author(s):  
Yuanyuan Cheng ◽  
Dandan Wang ◽  
Jingyan Gu ◽  
Junge Li ◽  
Huihui Liu ◽  
...  
Keyword(s):  
Alginate Lyase ◽  
Fluorescent Labeling ◽  
Structure Identification ◽  
Key Factors ◽  
Content Type ◽  
Biochemical Characteristics ◽  
Action Mode ◽  
Molecular Sizes ◽  
Sugar Chains ◽  
Alginate Lyases

ABSTRACT Bifunctional alginate lyases can efficiently degrade alginate comprised of mannuronate (M) and guluronate (G), but their substrate-degrading modes have not been thoroughly elucidated to date. In this study, we present Aly1 as a novel bifunctional endolytic alginate lyase of the genus Flammeovirga. The recombinant enzyme showed optimal activity at 50°C and pH 6.0. The enzyme produced unsaturated disaccharide (UDP2) and trisaccharide fractions as the final main alginate digests. Primary substrate preference tests and further structure identification of various size-defined final oligosaccharide products demonstrated that Aly1 is a bifunctional alginate lyase and prefers G to M. Tetrasaccharide-size fractions are the smallest substrates, and M, G, and UDP2 fractions are the minimal product types. Remarkably, Aly1 can vary its substrate-degrading modes in accordance with the terminus types, molecular sizes, and M/G contents of alginate substrates, producing a series of small size-defined saturated oligosaccharide products from the nonreducing ends of single or different saturated sugar chains and yielding unsaturated products in distinct but restricted patterns. The action mode changes can be partially inhibited by fluorescent labeling at the reducing ends of oligosaccharide substrates. Deletion of the noncatalytic region (NCR) of Aly1 caused weak changes of biochemical characteristics but increased the degradation proportions of small size-defined saturated M-enriched oligosaccharide substrates and unsaturated tetrasaccharide fractions without any size changes of degradable oligosaccharides, thereby enhancing the M preference and enzyme activity. Therefore, our results provided insight into the variable action mode of a novel bifunctional endolytic alginate lyase to inform accurate enzyme use. IMPORTANCE The elucidated endolytic alginate lyases usually degrade substrates into various size-defined unsaturated oligosaccharide products (≥UDP2), and exolytic enzymes yield primarily unsaturated monosaccharide products. However, it is poorly understood whether endolytic enzymes can produce monosaccharide product types when degrading alginate. In this study, we demonstrated that Aly1, a bifunctional alginate lyase of Flammeovirga sp. strain MY04, is endolytic and monosaccharide producing. Using various sugar chains as testing substrates, we also proved that key factors causing Aly1's action mode changes are the terminus types, molecular sizes, and M/G contents of substrates. Furthermore, the NCR fragment's effects on Aly1's biochemical characteristics and alginate-degrading modes and corresponding mechanisms were discovered by gene truncation and enzyme comparison. In summary, this study provides a novel bifunctional endolytic tool and a variable action mode for accurate use in alginate degradation.

scholarly journals Biochemical characteristics and synergistic effect of two novel alginate lyases from Photobacterium sp. FC615

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Danrong Lu ◽  
Qingdong Zhang ◽  
Shumin Wang ◽  
Jingwen Guan ◽  
Runmiao Jiao ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Synergistic Effect ◽  
Alginate Lyase ◽  
Enzymatic Digestion ◽  
Biofuel Production ◽  
Molar Ratio ◽  
Brown Macroalgae ◽  
Alginate Oligosaccharides ◽  
Novel Method ◽  
Alginate Lyases

Abstract Background Macroalgae and microalgae, as feedstocks for third-generation biofuel, possess competitive strengths in terms of cost, technology and economics. The most important compound in brown macroalgae is alginate, and the synergistic effect of endolytic and exolytic alginate lyases plays a crucial role in the saccharification process of transforming alginate into biofuel. However, there are few studies on the synergistic effect of endolytic and exolytic alginate lyases, especially those from the same bacterial strain. Results In this study, the endolytic alginate lyase AlyPB1 and exolytic alginate lyase AlyPB2 were identified from the marine bacterium Photobacterium sp. FC615. These two enzymes showed quite different and novel enzymatic properties whereas behaved a strong synergistic effect on the saccharification of alginate. Compared to that when AlyPB2 was used alone, the conversion rate of alginate polysaccharides to unsaturated monosaccharides when AlyPB1 and AlyPB2 acted on alginate together was dramatically increased approximately sevenfold. Furthermore, we found that AlyPB1 and AlyPB2 acted the synergistic effect basing on the complementarity of their substrate degradation patterns, particularly due to their M-/G-preference and substrate-size dependence. In addition, a novel method for sequencing alginate oligosaccharides was developed for the first time by combining the 1H NMR spectroscopy and the enzymatic digestion with the exo-lyase AlyPB2, and this method is much simpler than traditional methods based on one- and two-dimensional NMR spectroscopy. Using this strategy, the sequences of the final tetrasaccharide and pentasaccharide product fractions produced by AlyPB1 were easily determined: the tetrasaccharide fractions contained two structures, ΔGMM and ΔMMM, at a molar ratio of 1:3.2, and the pentasaccharide fractions contained four structures, ΔMMMM, ΔMGMM, ΔGMMM, and ΔGGMM, at a molar ratio of ~ 1:1.5:3.5:5.25. Conclusions The identification of these two novel alginate lyases provides not only excellent candidate tool-type enzymes for oligosaccharide preparation but also a good model for studying the synergistic digestion and saccharification of alginate in biofuel production. The novel method for oligosaccharide sequencing described in this study will offer a very useful approach for structural and functional studies on alginate.

scholarly journals Biochemical Characterization and Degradation Pattern of a Novel Endo-Type Bifunctional Alginate Lyase AlyA from Marine Bacterium Isoptericola halotolerans

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 258 ◽  
Author(s):  
Benwei Zhu ◽  
Limin Ning ◽  
Yucui Jiang ◽  
Lin Ge
Keyword(s):  
Substrate Specificity ◽  
Biochemical Characterization ◽  
Alginate Lyase ◽  
Ionization Mass ◽  
Broad Substrate Specificity ◽  
Action Mode ◽  
Degradation Pattern ◽  
Km Value ◽  
Alginate Lyases ◽  
Layer Chromatography

Alginate lyases are important tools to prepare oligosaccharides with various physiological activities by degrading alginate. Particularly, the bifunctional alginate lyase can efficiently hydrolyze the polysaccharide into oligosaccharides. Herein, we cloned and identified a novel bifunctional alginate lyase, AlyA, with a high activity and broad substrate specificity from bacterium Isoptericola halotolerans NJ-05 for oligosaccharides preparation. For further applications in industry, the enzyme has been characterized and its action mode has been also elucidated. It exhibited the highest activity (7984.82 U/mg) at pH 7.5 and 55 °C. Additionally, it possessed a broad substrate specificity, showing high activities towards not only polyM (polyβ-d-mannuronate) (7658.63 U/mg), but also polyG (poly α-l-guluronate) (8643.29 U/mg). Furthermore, the Km value of AlyA towards polyG (3.2 mM) was lower than that towards sodium alginate (5.6 mM) and polyM (6.7 mM). TLC (Thin Layer Chromatography) and ESI-MS (Electrospray Ionization Mass Spectrometry) were used to study the action mode of the enzyme, showing that it can hydrolyze the substrates in an endolytic manner to release a series of oligosaccharides such as disaccharide, trisaccharide, and tetrasaccharide. This study provided extended insights into the substrate recognition and degrading pattern of the alginate lyases, with a broad substrate specificity.

scholarly journals Specificities and Synergistic Actions of Novel PL8 and PL7 Alginate Lyases from the Marine Fungus Paradendryphiella salina

2021 ◽  
Vol 7 (2) ◽  
pp. 80
Author(s):  
Bo Pilgaard ◽  
Marlene Vuillemin ◽  
Jesper Holck ◽  
Casper Wilkens ◽  
Anne S. Meyer
Keyword(s):  
Alginate Lyase ◽  
Marine Fungus ◽  
Brown Macroalgae ◽  
Polysaccharide Lyases ◽  
Alginate Lyases ◽  
Encoding Genes ◽  
Substrate Affinities ◽  
Alginate Degradation ◽  
Insight Into

Alginate is an anionic polysaccharide abundantly present in the cell walls of brown macroalgae. The enzymatic depolymerization is performed solely by alginate lyases (EC 4.2.2.x), categorized as polysaccharide lyases (PLs) belonging to 12 different PL families. Until now, the vast majority of the alginate lyases have been found in bacteria. We report here the first extensive characterization of four alginate lyases from a marine fungus, the ascomycete Paradendryphiella salina, a known saprophyte of seaweeds. We have identified four polysaccharide lyase encoding genes bioinformatically in P. salina, one PL8 (PsMan8A), and three PL7 alginate lyases (PsAlg7A, -B, and -C). PsMan8A was demonstrated to exert exo-action on polymannuronic acid, and no action on alginate, indicating that this enzyme is most likely an exo-acting polymannuronic acid specific lyase. This enzyme is the first alginate lyase assigned to PL8 and polymannuronic acid thus represents a new substrate specificity in this family. The PL7 lyases (PsAlg7A, -B, and -C) were found to be endo-acting alginate lyases with different activity optima, substrate affinities, and product profiles. PsAlg7A and PsMan8A showed a clear synergistic action for the complete depolymerization of polyM at pH 5. PsAlg7A depolymerized polyM to mainly DP5 and DP3 oligomers and PsMan8A to dimers and monosaccharides. PsAlg7B and PsAlg7C showed substrate affinities towards both polyM and polyG at pH 8, depolymerizing both substrates to DP9-DP2 oligomers. The findings elucidate how P. salina accomplishes alginate depolymerization and provide insight into an efficient synergistic cooperation that may provide a new foundation for enzyme selection for alginate degradation in seaweed bioprocessing.

scholarly journals Known Evolutionary Paths Are Accessible to Engineered ß-Lactamases Having Altered Protein Motions at the Timescale of Catalytic Turnover

2020 ◽  
Vol 7 ◽  
Author(s):  
Lorea Alejaldre ◽  
Claudèle Lemay-St-Denis ◽  
Carles Perez Lopez ◽  
Ferran Sancho Jodar ◽  
Victor Guallar ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Synergistic Effect ◽  
Protein Dynamics ◽  
Catalytic Efficiency ◽  
Specific Sequence ◽  
Protein Motions ◽  
Protein Energy ◽  
Protein Functions ◽  
Directed Molecular Evolution

The evolution of new protein functions is dependent upon inherent biophysical features of proteins. Whereas, it has been shown that changes in protein dynamics can occur in the course of directed molecular evolution trajectories and contribute to new function, it is not known whether varying protein dynamics modify the course of evolution. We investigate this question using three related ß-lactamases displaying dynamics that differ broadly at the slow timescale that corresponds to catalytic turnover yet have similar fast dynamics, thermal stability, catalytic, and substrate recognition profiles. Introduction of substitutions E104K and G238S, that are known to have a synergistic effect on function in the parent ß-lactamase, showed similar increases in catalytic efficiency toward cefotaxime in the related ß-lactamases. Molecular simulations using Protein Energy Landscape Exploration reveal that this results from stabilizing the catalytically-productive conformations, demonstrating the dominance of the synergistic effect of the E014K and G238S substitutions in vitro in contexts that vary in terms of sequence and dynamics. Furthermore, three rounds of directed molecular evolution demonstrated that known cefotaximase-enhancing mutations were accessible regardless of the differences in dynamics. Interestingly, specific sequence differences between the related ß-lactamases were shown to have a higher effect in evolutionary outcomes than did differences in dynamics. Overall, these ß-lactamase models show tolerance to protein dynamics at the timescale of catalytic turnover in the evolution of a new function.

scholarly journals Characterization of a New Intracellular Alginate Lyase with Metal Ions-Tolerant and pH-Stable Properties

Marine Drugs ◽  
2020 ◽  
Vol 18 (8) ◽  
pp. 416
Author(s):  
Yan Ma ◽  
Jie Li ◽  
Xin-Yue Zhang ◽  
Hao-Dong Ni ◽  
Feng-Biao Wang ◽  
...  
Keyword(s):  
Metal Ion ◽  
Brown Seaweed ◽  
Alginate Lyase ◽  
Industrial Applications ◽  
Alginate Oligosaccharides ◽  
Potential Applications ◽  
Pharmaceutical Industries ◽  
Ph Range ◽  
Alginate Lyases

Alginate lyases play an important role in alginate oligosaccharides (AOS) preparation and brown seaweed processing. Many extracellular alginate lyases have been characterized to develop efficient degradation tools needed for industrial applications. However, few studies focusing on intracellular alginate lyases have been conducted. In this work, a novel intracellular alkaline alginate lyase Alyw202 from Vibrio sp. W2 was cloned, expressed and characterized. Secretory expression was performed in a food-grade host, Yarrowia lipolytica. Recombinant Alyw202 with a molecular weight of approximately 38.3 kDa exhibited the highest activity at 45 °C and more than 60% of the activity in a broad pH range of 3.0 to 10.0. Furthermore, Alyw202 showed remarkable metal ion-tolerance, NaCl independence and the capacity of degrading alginate into oligosaccharides of DP2-DP4. Due to the unique pH-stable and high salt-tolerant properties, Alyw202 has potential applications in the food and pharmaceutical industries.

scholarly journals Biochemical Characterization and Elucidation of Action Pattern of a Novel Polysaccharide Lyase 6 Family Alginate Lyase from Marine Bacterium Flammeovirga sp. NJ-04

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 323 ◽  
Author(s):  
Qian Li ◽  
Fu Hu ◽  
Benwei Zhu ◽  
Yun Sun ◽  
Zhong Yao
Keyword(s):  
Biochemical Characterization ◽  
Alginate Lyase ◽  
Ionization Mass ◽  
Action Pattern ◽  
Polysaccharide Lyase ◽  
Glycosidic Bonds ◽  
Alginate Oligosaccharides ◽  
Degradation Pattern ◽  
Alginate Lyases ◽  
Layer Chromatography

Alginate lyases have been widely used to prepare alginate oligosaccharides in food, agricultural, and medical industries. Therefore, discovering and characterizing novel alginate lyases with excellent properties has drawn increasing attention. Herein, a novel alginate lyase FsAlyPL6 of Polysaccharide Lyase (PL) 6 family is identified and biochemically characterized from Flammeovirga sp. NJ-04. It shows highest activity at 45 °C and could retain 50% of activity after being incubated at 45 °C for 1 h. The Thin-Layer Chromatography (TLC) and Electrospray Ionization Mass Spectrometry (ESI-MS) analysis indicates that FsAlyPL6 endolytically degrades alginate polysaccharide into oligosaccharides ranging from monosaccharides to pentasaccharides. In addition, the action pattern of the enzyme is also elucidated and the result suggests that FsAlyPL6 could recognize tetrasaccharide as the minimal substrate and cleave the glycosidic bonds between the subsites of −1 and +3. The research provides extended insights into the substrate recognition and degradation pattern of PL6 alginate lyases, which may further expand the application of alginate lyases.

scholarly journals Improvement in catalytic activity and thermostability of a GH10 xylanase and its synergistic degradation of biomass with cellulase

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuai You ◽  
Chen Xie ◽  
Rui Ma ◽  
Huo-qing Huang ◽  
Richard Ansah Herman ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Dry Matter ◽  
Specific Activity ◽  
Xylanase Activity ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Biomass Degradation ◽  
Synergistic Degradation ◽  
Gh10 Xylanase ◽  
Hybrid Enzymes

Abstract Background Xylanase is one of the most extensively used biocatalysts for biomass degradation. However, its low catalytic efficiency and poor thermostability limit its applications. Therefore, improving the properties of xylanases to enable synergistic degradation of lignocellulosic biomass with cellulase is of considerable significance in the field of bioenergy. Results Using fragment replacement, we improved the catalytic performance and thermostability of a GH10 xylanase, XylE. Of the ten hybrid enzymes obtained, seven showed xylanase activity. Substitution of fragments, M3, M6, M9, and their combinations enhanced the catalytic efficiency (by 2.4- to fourfold) as well as the specific activity (by 1.2- to 3.3-fold) of XylE. The hybrids, XylE-M3, XylE-M3/M6, XylE-M3/M9, and XylE-M3/M6/M9, showed enhanced thermostability, as observed by the increase in the T50 (3–4.7 °C) and Tm (1.1–4.7 °C), and extended t1/2 (by 1.8–2.3 h). In addition, the synergistic effect of the mutant xylanase and cellulase on the degradation of mulberry bark showed that treatment with both XylE-M3/M6 and cellulase exhibited the highest synergistic effect. In this case, the degree of synergy reached 1.3, and the reducing sugar production and dry matter reduction increased by 148% and 185%, respectively, compared to treatment with only cellulase. Conclusions This study provides a successful strategy to improve the catalytic properties and thermostability of enzymes. We identified several xylanase candidates for applications in bioenergy and biorefinery. Synergistic degradation experiments elucidated a possible mechanism of cellulase inhibition by xylan and xylo-oligomers.

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