1
|
Zhang Y, Li Y, Lin H, Mao G, Long X, Liu X, Chen H. Broadening the Substrate Specificity of Cellobiose Phosphorylase from Clostridium thermocellum for Improved Transformation of Cellodextrin to Starch. Int J Mol Sci 2023; 24:14452. [PMID: 37833899 PMCID: PMC10572201 DOI: 10.3390/ijms241914452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023] Open
Abstract
Cellobiose phosphorylase (CBP) catalyzes the reversible phosphorolysis of cellobiose into α-glucose 1-phosphate and glucose. A CBP with a broadened substrate specificity would be more desirable when utilized to convert cellulose into amylose (PNAS, 110: 7182-7187, 2013) and to construct yeast that can phosphorolytically use cellodextrin to produce ethanol. Based on the structure differences in the catalytic loops of CBP and cellodextrin phosphorylase from Clostridium thermocellum (named CtCBP and CtCDP, respectively), CtCBP was mutated to change its substrate specificity. A single-site mutant S497G was identified to exhibit a 5.7-fold higher catalytic efficiency with cellotriose as a substrate in the phosphorolytic reaction compared to the wild type, without any loss of catalytic efficiency on its natural substrate, cellobiose. When the S497G variant was used in the transformation of mixed cellodextrin (cellobiose + cellotriose) to amylose, the amylose yield was significantly increased compared to that of wild-type CtCBP. A structure change in the substrate-binding pocket of the S497G variant accounted for its capacity to accept longer cellodextrins than cellobiose. Taken together, the modified CtCBP, S497G was confirmed to acquire a promising feature favorable to those application scenarios involving cellodextrin's phosphorolysis.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Hongge Chen
- College of Life Sciences, Henan Agricultural University, Zhengzhou 450046, China; (Y.Z.); (Y.L.); (H.L.); (G.M.); (X.L.); (X.L.)
| |
Collapse
|
2
|
Storani A, Guerrero SA, Iglesias AA. Insights to improve the activity of glycosyl phosphorylases from Ruminococcus albus 8 with cello-oligosaccharides. Front Chem 2023; 11:1176537. [PMID: 37090251 PMCID: PMC10119399 DOI: 10.3389/fchem.2023.1176537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 03/30/2023] [Indexed: 04/25/2023] Open
Abstract
The phosphorolysis of cello-oligosaccharides is a critical process played in the rumen by Ruminococcus albus to degrade cellulose. Cellodextrins, made up of a few glucosyl units, have gained lots of interest by their potential applications. Here, we characterized a cellobiose phosphorylase (RalCBP) and a cellodextrin phosphorylase (RalCDP) from R. albus 8. This latter was further analyzed in detail by constructing a truncated mutant (Ral∆N63CDP) lacking the N-terminal domain and a chimeric protein by fusing a CBM (RalCDP-CBM37). RalCBP showed a typical behavior with high activity on cellobiose. Instead, RalCDP extended its activity to longer soluble or insoluble cello-oligosaccharides. The catalytic efficiency of RalCDP was higher with cellotetraose and cellopentaose as substrates for both reaction directions. Concerning properties of Ral∆N63CDP, results support roles for the N-terminal domain in the conformation of the homo-dimer and conferring the enzyme the capacity to catalyze the phosphorolytic reaction. This mutant exhibited reduced affinity toward phosphate and increased to glucose-1-phosphate. Further, the CBM37 module showed functionality when fused to RalCDP, as RalCDP-CBM37 exhibited an enhanced ability to use insoluble cellulosic substrates. Data obtained from this enzyme's binding parameters to cellulosic polysaccharides agree with the kinetic results. Besides, studies of synthesis and phosphorolysis of cello-saccharides at long-time reactions served to identify the utility of these enzymes. While RalCDP produces a mixture of cello-oligosaccharides (from cellotriose to longer oligosaccharides), the impaired phosphorolytic activity makes Ral∆N63CDP lead mainly toward the synthesis of cellotetraose. On the other hand, RalCDP-CBM37 remarks on the utility of obtaining glucose-1-phosphate from cellulosic compounds.
Collapse
|
3
|
Ricci S, Pacífico C, Castillo-Lopez E, Rivera-Chacon R, Schwartz-Zimmermann HE, Reisinger N, Berthiller F, Zebeli Q, Petri RM. Progressive microbial adaptation of the bovine rumen and hindgut in response to a step-wise increase in dietary starch and the influence of phytogenic supplementation. Front Microbiol 2022; 13:920427. [PMID: 35935232 PMCID: PMC9354822 DOI: 10.3389/fmicb.2022.920427] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/27/2022] [Indexed: 01/08/2023] Open
Abstract
Microbial composition and activity in the gastrointestinal tract (GIT) of cattle has important implications for animal health and welfare, driving the focus of research toward ways to modify their function and abundance. However, our understanding of microbial adaption to nutritional changes remains limited. The aim of this study was to examine the progressive mechanisms of adaptation in the rumen and hindgut of cattle receiving increasing amounts of starch with or without dietary supplementation of a blended phytogenic feed additive (PFA; containing menthol, thymol and eugenol). We used 16S rRNA gene amplicon sequencing to assess the microbial composition and predicted metabolic pathways in ruminal solid and liquid digesta, and feces. Furthermore, we employed targeted liquid chromatography-mass spectrometry methods to evaluate rumen fluid metabolites. Results indicated a rapid microbial adaptation to diet change, starting on the second day of starch feeding for the particle associated rumen liquid (PARL) microbes. Solid rumen digesta- and feces-associated microbes started changing from the following day. The PARL niche was the most responsive to dietary changes, with the highest number of taxa and predicted pathways affected by the increase in starch intake, as well as by the phytogenic supplementation. Despite the differences in the microbial composition and metabolic potential of the different GIT niches, all showed similar changes toward carbohydrate metabolism. Metabolite measurement confirmed the high prevalence of glucose and volatile fatty acids (VFAs) in the rumen due to the increased substrate availability and metabolic activity of the microbiota. Families Prevotellaceae, Ruminococcaceae and Lachnospiraceae were found to be positively correlated with carbohydrate metabolism, with the latter two showing wide-ranging predicted metabolic capabilities. Phytogenic supplementation affected low abundant taxa and demonstrated the potential to prevent unwanted implications of feeding high-concentrate diet, such as reduction of microbial diversity. The inclusion of 50% concentrate in the diet caused a major shift in microbial composition and activity in the GIT of cattle. This study demonstrated the ability of microorganisms in various GIT niches to adjust differentially, yet rapidly, to changing dietary conditions, and revealed the potential beneficial effects of supplementation with a PFA during dietary adaptation.
Collapse
Affiliation(s)
- Sara Ricci
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine, Vienna, Austria
- *Correspondence: Sara Ricci
| | - Cátia Pacífico
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine, Vienna, Austria
| | - Ezequias Castillo-Lopez
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine, Vienna, Austria
| | - Raul Rivera-Chacon
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine, Vienna, Austria
| | - Heidi E. Schwartz-Zimmermann
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna, Austria
| | | | - Franz Berthiller
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Qendrim Zebeli
- Christian Doppler Laboratory for Innovative Gut Health Concepts of Livestock, Department for Farm Animals and Veterinary Public Health, Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine, Vienna, Austria
| | - Renee M. Petri
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada
| |
Collapse
|
4
|
Discovery and Biotechnological Exploitation of Glycoside-Phosphorylases. Int J Mol Sci 2022; 23:ijms23063043. [PMID: 35328479 PMCID: PMC8950772 DOI: 10.3390/ijms23063043] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Among carbohydrate active enzymes, glycoside phosphorylases (GPs) are valuable catalysts for white biotechnologies, due to their exquisite capacity to efficiently re-modulate oligo- and poly-saccharides, without the need for costly activated sugars as substrates. The reversibility of the phosphorolysis reaction, indeed, makes them attractive tools for glycodiversification. However, discovery of new GP functions is hindered by the difficulty in identifying them in sequence databases, and, rather, relies on extensive and tedious biochemical characterization studies. Nevertheless, recent advances in automated tools have led to major improvements in GP mining, activity predictions, and functional screening. Implementation of GPs into innovative in vitro and in cellulo bioproduction strategies has also made substantial advances. Herein, we propose to discuss the latest developments in the strategies employed to efficiently discover GPs and make the best use of their exceptional catalytic properties for glycoside bioproduction.
Collapse
|
5
|
Bai S, Yang L, Wang H, Yang C, Hou X, Gao J, Zhang Z. Cellobiose phosphorylase from Caldicellulosiruptor bescii catalyzes reversible phosphorolysis via different kinetic mechanisms. Sci Rep 2022; 12:3978. [PMID: 35273293 PMCID: PMC8913831 DOI: 10.1038/s41598-022-08036-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/01/2022] [Indexed: 01/01/2023] Open
Abstract
In the process of yielding biofuels from cellulose degradation, traditional enzymatic hydrolysis, such as β-glucosidase catalyzing cellobiose, can barely resolve the contradiction between cellulose degradation and bioenergy conservation. However, it has been shown that cellobiose phosphorylase provides energetic advantages for cellobiose degradation through a phosphorolytic pathway, which has attracted wide attention. Here, the cellobiose phosphorylase gene from Caldicellulosiruptor bescii (CbCBP) was cloned, expressed, and purified. Analysis of the enzymatic properties and kinetic mechanisms indicated that CbCBP catalyzed reversible phosphorolysis and had good thermal stability and broad substrate selectivity. In addition, the phosphorolytic reaction of cellobiose by CbCBP proceeded via an ordered Bi Bi mechanism, while the synthetic reaction proceeded via a ping pong Bi Bi mechanism. The present study lays the foundation for optimizing the degradation of cellulose and the synthesis of functional oligosaccharides.
Collapse
Affiliation(s)
- Shaowei Bai
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China
| | - Liangzhen Yang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China
| | - Honglei Wang
- School of Chemistry and Life Science, Changchun University of Technology, Changchun, 130012, China
| | - Chao Yang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China
| | - Xuechen Hou
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China
| | - Jingjie Gao
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China
| | - Zuoming Zhang
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, China.
| |
Collapse
|
6
|
β-Glucan phosphorylases in carbohydrate synthesis. Appl Microbiol Biotechnol 2021; 105:4073-4087. [PMID: 33970317 PMCID: PMC8140972 DOI: 10.1007/s00253-021-11320-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 01/02/2023]
Abstract
Abstract β-Glucan phosphorylases are carbohydrate-active enzymes that catalyze the reversible degradation of β-linked glucose polymers, with outstanding potential for the biocatalytic bottom-up synthesis of β-glucans as major bioactive compounds. Their preference for sugar phosphates (rather than nucleotide sugars) as donor substrates further underlines their significance for the carbohydrate industry. Presently, they are classified in the glycoside hydrolase families 94, 149, and 161 (www.cazy.org). Since the discovery of β-1,3-oligoglucan phosphorylase in 1963, several other specificities have been reported that differ in linkage type and/or degree of polymerization. Here, we present an overview of the progress that has been made in our understanding of β-glucan and associated β-glucobiose phosphorylases, with a special focus on their application in the synthesis of carbohydrates and related molecules. Key points • Discovery, characteristics, and applications of β-glucan phosphorylases. • β-Glucan phosphorylases in the production of functional carbohydrates.
Collapse
|
7
|
Nidetzky B, Zhong C. Phosphorylase-catalyzed bottom-up synthesis of short-chain soluble cello-oligosaccharides and property-tunable cellulosic materials. Biotechnol Adv 2020; 51:107633. [PMID: 32966861 DOI: 10.1016/j.biotechadv.2020.107633] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 08/23/2020] [Accepted: 09/06/2020] [Indexed: 12/13/2022]
Abstract
Cellulose-based materials are produced industrially in countless varieties via top-down processing of natural lignocellulose substrates. By contrast, cellulosic materials are only rarely prepared via bottom up synthesis and oligomerization-induced self-assembly of cellulose chains. Building up a cellulose chain via precision polymerization is promising, however, for it offers tunability and control of the final chemical structure. Synthetic cellulose derivatives with programmable material properties might thus be obtained. Cellodextrin phosphorylase (CdP; EC 2.4.1.49) catalyzes iterative β-1,4-glycosylation from α-d-glucose 1-phosphate, with the ability to elongate a diversity of acceptor substrates, including cellobiose, d-glucose and a range of synthetic glycosides having non-sugar aglycons. Depending on the reaction conditions leading to different degrees of polymerization (DP), short-chain soluble cello-oligosaccharides (COS) or insoluble cellulosic materials are formed. Here, we review the characteristics of CdP as bio-catalyst for synthetic applications and show advances in the enzymatic production of COS and reducing end-modified, tailored cellulose materials. Recent studies reveal COS as interesting dietary fibers that could provide a selective prebiotic effect. The bottom-up synthesized celluloses involve chains of DP ≥ 9, as precipitated in solution, and they form ~5 nm thick sheet-like crystalline structures of cellulose allomorph II. Solvent conditions and aglycon structures can direct the cellulose chain self-assembly towards a range of material architectures, including hierarchically organized networks of nanoribbons, or nanorods as well as distorted nanosheets. Composite materials are also formed. The resulting materials can be useful as property-tunable hydrogels and feature site-specific introduction of functional and chemically reactive groups. Therefore, COS and cellulose obtained via bottom-up synthesis can expand cellulose applications towards product classes that are difficult to access via top-down processing of natural materials.
Collapse
Affiliation(s)
- Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, Graz 8010, Austria; Austrian Centre of Industrial Biotechnology (acib), Krenngasse 37, Graz 8010, Austria.
| | - Chao Zhong
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, Graz 8010, Austria
| |
Collapse
|
8
|
Liu N, Fosses A, Kampik C, Parsiegla G, Denis Y, Vita N, Fierobe HP, Perret S. In vitro and in vivo exploration of the cellobiose and cellodextrin phosphorylases panel in Ruminiclostridium cellulolyticum: implication for cellulose catabolism. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:208. [PMID: 31497068 PMCID: PMC6720390 DOI: 10.1186/s13068-019-1549-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 08/24/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND In anaerobic cellulolytic micro-organisms, cellulolysis results in the action of several cellulases gathered in extracellular multi-enzyme complexes called cellulosomes. Their action releases cellobiose and longer cellodextrins which are imported and further degraded in the cytosol to fuel the cells. In Ruminiclostridium cellulolyticum, an anaerobic and cellulolytic mesophilic bacteria, three cellodextrin phosphorylases named CdpA, CdpB, and CdpC, were identified in addition to the cellobiose phosphorylase (CbpA) previously characterized. The present study aimed at characterizing them, exploring their implication during growth on cellulose to better understand the life-style of cellulolytic bacteria on such substrate. RESULTS The three cellodextrin phosphorylases from R. cellulolyticum displayed marked different enzymatic characteristics. They are specific for cellodextrins of different lengths and present different k cat values. CdpC is the most active enzyme before CdpA, and CdpB is weakly active. Modeling studies revealed that a mutation of a conserved histidine residue in the phosphate ion-binding pocket in CdpB and CdpC might explain their activity-level differences. The genes encoding these enzymes are scattered over the chromosome of R. cellulolyticum and only the expression of the gene encoding the cellobiose phosphorylase and the gene cdpA is induced during cellulose growth. Characterization of four independent mutants constructed in R. cellulolyticum for each of the cellobiose and cellodextrin phosphorylases encoding genes indicated that only the cellobiose phosphorylase is essential for growth on cellulose. CONCLUSIONS Unexpectedly, the cellobiose phosphorylase but not the cellodextrin phosphorylases is essential for the growth of the model bacterium on cellulose. This suggests that the bacterium adopts a "short" dextrin strategy to grow on cellulose, even though the use of long cellodextrins might be more energy-saving. Our results suggest marked differences in the cellulose catabolism developed among cellulolytic bacteria, which is a result that might impact the design of future engineered strains for biomass-to-biofuel conversion.
Collapse
Affiliation(s)
- Nian Liu
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Aurélie Fosses
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Clara Kampik
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | | | - Yann Denis
- Aix-Marseille Univ, CNRS, Plateforme Transcriptome, Marseille, France
| | - Nicolas Vita
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Henri-Pierre Fierobe
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Stéphanie Perret
- Aix-Marseille Univ, CNRS, LCB UMR 7283, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| |
Collapse
|
9
|
Gao Y, Saburi W, Taguchi Y, Mori H. Biochemical characteristics of maltose phosphorylase MalE from Bacillus sp. AHU2001 and chemoenzymatic synthesis of oligosaccharides by the enzyme. Biosci Biotechnol Biochem 2019; 83:2097-2109. [PMID: 31262243 DOI: 10.1080/09168451.2019.1634516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Maltose phosphorylase (MP), a glycoside hydrolase family 65 enzyme, reversibly phosphorolyzes maltose. In this study, we characterized Bacillus sp. AHU2001 MP (MalE) that was produced in Escherichia coli. The enzyme exhibited phosphorolytic activity to maltose, but not to other α-linked glucobioses and maltotriose. The optimum pH and temperature of MalE for maltose-phosphorolysis were 8.1 and 45°C, respectively. MalE was stable at a pH range of 4.5-10.4 and at ≤40°C. The phosphorolysis of maltose by MalE obeyed the sequential Bi-Bi mechanism. In reverse phosphorolysis, MalE utilized d-glucose, 1,5-anhydro-d-glucitol, methyl α-d-glucoside, 2-deoxy-d-glucose, d-mannose, d-glucosamine, N-acetyl-d-glucosamine, kojibiose, 3-deoxy-d-glucose, d-allose, 6-deoxy-d-glucose, d-xylose, d-lyxose, l-fucose, and l-sorbose as acceptors. The kcat(app)/Km(app) value for d-glucosamine and 6-deoxy-d-glucose was comparable to that for d-glucose, and that for other acceptors was 0.23-12% of that for d-glucose. MalE synthesized α-(1→3)-glucosides through reverse phosphorolysis with 2-deoxy-d-glucose and l-sorbose, and synthesized α-(1→4)-glucosides in the reaction with other tested acceptors.
Collapse
Affiliation(s)
- Yu Gao
- Research Faculty of Agriculture, Hokkaido University , Sapporo , Japan
| | - Wataru Saburi
- Research Faculty of Agriculture, Hokkaido University , Sapporo , Japan
| | - Yodai Taguchi
- Research Faculty of Agriculture, Hokkaido University , Sapporo , Japan
| | - Haruhide Mori
- Research Faculty of Agriculture, Hokkaido University , Sapporo , Japan
| |
Collapse
|
10
|
Kuhaudomlarp S, Walpole S, Stevenson CEM, Nepogodiev SA, Lawson DM, Angulo J, Field RA. Unravelling the Specificity of Laminaribiose Phosphorylase from Paenibacillus sp. YM-1 towards Donor Substrates Glucose/Mannose 1-Phosphate by Using X-ray Crystallography and Saturation Transfer Difference NMR Spectroscopy. Chembiochem 2018; 20:181-192. [PMID: 29856496 DOI: 10.1002/cbic.201800260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Indexed: 12/13/2022]
Abstract
Glycoside phosphorylases (GPs) carry out a reversible phosphorolysis of carbohydrates into oligosaccharide acceptors and the corresponding sugar 1-phosphates. The reversibility of the reaction enables the use of GPs as biocatalysts for carbohydrate synthesis. Glycosyl hydrolase family 94 (GH94), which only comprises GPs, is one of the most studied GP families that have been used as biocatalysts for carbohydrate synthesis, in academic research and in industrial production. Understanding the mechanism of GH94 enzymes is a crucial step towards enzyme engineering to improve and expand the applications of these enzymes in synthesis. In this work with a GH94 laminaribiose phosphorylase from Paenibacillus sp. YM-1 (PsLBP), we have demonstrated an enzymatic synthesis of disaccharide 1 (β-d-mannopyranosyl-(1→3)-d-glucopyranose) by using a natural acceptor glucose and noncognate donor substrate α-mannose 1-phosphate (Man1P). To investigate how the enzyme recognises different sugar 1-phosphates, the X-ray crystal structures of PsLBP in complex with Glc1P and Man1P have been solved, providing the first molecular detail of the recognition of a noncognate donor substrate by GPs, which revealed the importance of hydrogen bonding between the active site residues and hydroxy groups at C2, C4, and C6 of sugar 1-phosphates. Furthermore, we used saturation transfer difference NMR spectroscopy to support crystallographic studies on the sugar 1-phosphates, as well as to provide further insights into the PsLBP recognition of the acceptors and disaccharide products.
Collapse
Affiliation(s)
- Sakonwan Kuhaudomlarp
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Samuel Walpole
- School of Pharmacy, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Clare E M Stevenson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Sergey A Nepogodiev
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - David M Lawson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Jesus Angulo
- School of Pharmacy, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| |
Collapse
|
11
|
Wu Y, Mao G, Fan H, Song A, Zhang YHP, Chen H. Biochemical properties of GH94 cellodextrin phosphorylase THA_1941 from a thermophilic eubacterium Thermosipho africanus TCF52B with cellobiose phosphorylase activity. Sci Rep 2017; 7:4849. [PMID: 28687766 PMCID: PMC5501786 DOI: 10.1038/s41598-017-05289-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/26/2017] [Indexed: 11/10/2022] Open
Abstract
A hypothetic gene (THA_1941) encoding a putative cellobiose phosphorylase (CBP) from Thermosipho africanus TCF52B has very low amino acid identities (less than 12%) to all known GH94 enzymes. This gene was cloned and over-expressed in Escherichia coli BL21(DE3). The recombinant protein was hypothesized to be a CBP enzyme and it showed an optimum temperature of 75 °C and an optimum pH of 7.5. Beyond its CBP activity, this enzyme can use cellobiose and long-chain cellodextrins with a degree of polymerization of greater than two as a glucose acceptor, releasing phosphate from glucose 1-phosphate. The catalytic efficiencies (kcat/Km) indicated that cellotetraose and cellopentaose were the best substrates for the phosphorolytic and reverse synthetic reactions, respectively. These results suggested that this enzyme was the first enzyme having both cellodextrin and cellobiose phosphorylases activities. Because it preferred cellobiose and cellodextrins to glucose in the synthetic direction, it was categorized as a cellodextrin phosphorylase (CDP). Due to its unique ability of the reverse synthetic reaction, this enzyme could be a potential catalyst for the synthesis of various oligosaccharides. The speculative function of this CDP in the carbohydrate metabolism of T. africanus TCF52B was also discussed.
Collapse
Affiliation(s)
- Yuanyuan Wu
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Guotao Mao
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Haiyan Fan
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Andong Song
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Yi-Heng Percival Zhang
- Biological Systems Engineering Department, Virginia Tech, 304 Seitz Hall, Blacksburg, Virginia, 24061, USA
| | - Hongge Chen
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
| |
Collapse
|
12
|
Chomvong K, Lin E, Blaisse M, Gillespie AE, Cate JHD. Relief of Xylose Binding to Cellobiose Phosphorylase by a Single Distal Mutation. ACS Synth Biol 2017; 6:206-210. [PMID: 27676450 DOI: 10.1021/acssynbio.6b00211] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cellobiose phosphorylase (CBP) cleaves cellobiose-abundant in plant biomass-to glucose and glucose 1-phosphate. However, the pentose sugar xylose, also abundant in plant biomass, acts as a mixed-inhibitor and a substrate for the reverse reaction, limiting the industrial potential of CBP. Preventing xylose, which lacks only a single hydroxymethyl group relative to glucose, from binding to the CBP active site poses a spatial challenge for protein engineering, since simple steric occlusion cannot be used to block xylose binding without also preventing glucose binding. Using CRISPR-based chromosomal library selection, we identified a distal mutation in CBP, Y47H, responsible for improved cellobiose consumption in the presence of xylose. In silico analysis suggests this mutation may alter the conformation of the cellobiose phosphorylase dimer complex to reduce xylose binding to the active site. These results may aid in engineering carbohydrate phosphorylases for improved specificity in biofuel production, and also in the production of industrially important oligosaccharides.
Collapse
Affiliation(s)
- Kulika Chomvong
- Department
of Plant and Microbial Biology, University of California, Berkeley, California 94720, United States
| | - Eric Lin
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
| | - Michael Blaisse
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Abigail E. Gillespie
- Department
of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Jamie H. D. Cate
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Department
of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
- Physical
Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|
13
|
Devendran S, Abdel-Hamid AM, Evans AF, Iakiviak M, Kwon IH, Mackie RI, Cann I. Multiple cellobiohydrolases and cellobiose phosphorylases cooperate in the ruminal bacterium Ruminococcus albus 8 to degrade cellooligosaccharides. Sci Rep 2016; 6:35342. [PMID: 27748409 PMCID: PMC5066209 DOI: 10.1038/srep35342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/28/2016] [Indexed: 12/01/2022] Open
Abstract
Digestion of plant cell wall polysaccharides is important in energy capture in the gastrointestinal tract of many herbivorous and omnivorous mammals, including humans and ruminants. The members of the genus Ruminococcus are found in both the ruminant and human gastrointestinal tract, where they show versatility in degrading both hemicellulose and cellulose. The available genome sequence of Ruminococcus albus 8, a common inhabitant of the cow rumen, alludes to a bacterium well-endowed with genes that target degradation of various plant cell wall components. The mechanisms by which R. albus 8 employs to degrade these recalcitrant materials are, however, not clearly understood. In this report, we demonstrate that R. albus 8 elaborates multiple cellobiohydrolases with multi-modular architectures that overall enhance the catalytic activity and versatility of the enzymes. Furthermore, our analyses show that two cellobiose phosphorylases encoded by R. albus 8 can function synergistically with a cognate cellobiohydrolase and endoglucanase to completely release, from a cellulosic substrate, glucose which can then be fermented by the bacterium for production of energy and cellular building blocks. We further use transcriptomic analysis to confirm the over-expression of the biochemically characterized enzymes during growth of the bacterium on cellulosic substrates compared to cellobiose.
Collapse
Affiliation(s)
- Saravanan Devendran
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ahmed M Abdel-Hamid
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Anton F Evans
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Michael Iakiviak
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - In Hyuk Kwon
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Roderick I Mackie
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Isaac Cann
- Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,School of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.,Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| |
Collapse
|
14
|
Puchart V. Glycoside phosphorylases: Structure, catalytic properties and biotechnological potential. Biotechnol Adv 2015; 33:261-76. [DOI: 10.1016/j.biotechadv.2015.02.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 02/06/2015] [Accepted: 02/07/2015] [Indexed: 12/20/2022]
|
15
|
Jaito N, Saburi W, Odaka R, Kido Y, Hamura K, Nishimoto M, Kitaoka M, Matsui H, Mori H. Characterization of a thermophilic 4-O-β-D-mannosyl-D-glucose phosphorylase from Rhodothermus marinus. Biosci Biotechnol Biochem 2014; 78:263-70. [PMID: 25036679 DOI: 10.1080/09168451.2014.882760] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
4-O-β-D-Mannosyl-D-glucose phosphorylase (MGP), found in anaerobes, converts 4-O-β-D-mannosyl-D-glucose (Man-Glc) to α-D-mannosyl phosphate and D-glucose. It participates in mannan metabolism with cellobiose 2-epimerase (CE), which converts β-1,4-mannobiose to Man-Glc. A putative MGP gene is present in the genome of the thermophilic aerobe Rhodothermus marinus (Rm) upstream of the gene encoding CE. Konjac glucomannan enhanced production by R. marinus of MGP, CE, and extracellular mannan endo-1,4-β-mannosidase. Recombinant RmMGP catalyzed the phosphorolysis of Man-Glc through a sequential bi-bi mechanism involving ternary complex formation. Its molecular masses were 45 and 222 kDa under denaturing and nondenaturing conditions, respectively. Its pH and temperature optima were 6.5 and 75 °C, and it was stable between pH 5.5-8.3 and below 80 °C. In the reverse reaction, RmMGP had higher acceptor preferences for 6-deoxy-D-glucose and D-xylose than R. albus NE1 MGP. In contrast to R. albus NE1 MGP, RmMGP utilized methyl β-D-glucoside and 1,5-anhydro-D-glucitol as acceptor substrates.
Collapse
Affiliation(s)
- Nongluck Jaito
- a Research Faculty of Agriculture , Hokkaido University , Sapporo , Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Chomvong K, Kordić V, Li X, Bauer S, Gillespie AE, Ha SJ, Oh EJ, Galazka JM, Jin YS, Cate JHD. Overcoming inefficient cellobiose fermentation by cellobiose phosphorylase in the presence of xylose. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:85. [PMID: 24944578 PMCID: PMC4061319 DOI: 10.1186/1754-6834-7-85] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/21/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND Cellobiose and xylose co-fermentation holds promise for efficiently producing biofuels from plant biomass. Cellobiose phosphorylase (CBP), an intracellular enzyme generally found in anaerobic bacteria, cleaves cellobiose to glucose and glucose-1-phosphate, providing energetic advantages under the anaerobic conditions required for large-scale biofuel production. However, the efficiency of CBP to cleave cellobiose in the presence of xylose is unknown. This study investigated the effect of xylose on anaerobic CBP-mediated cellobiose fermentation by Saccharomyces cerevisiae. RESULTS Yeast capable of fermenting cellobiose by the CBP pathway consumed cellobiose and produced ethanol at rates 61% and 42% slower, respectively, in the presence of xylose than in its absence. The system generated significant amounts of the byproduct 4-O-β-d-glucopyranosyl-d-xylose (GX), produced by CBP from glucose-1-phosphate and xylose. In vitro competition assays identified xylose as a mixed-inhibitor for cellobiose phosphorylase activity. The negative effects of xylose were effectively relieved by efficient cellobiose and xylose co-utilization. GX was also shown to be a substrate for cleavage by an intracellular β-glucosidase. CONCLUSIONS Xylose exerted negative impacts on CBP-mediated cellobiose fermentation by acting as a substrate for GX byproduct formation and a mixed-inhibitor for cellobiose phosphorylase activity. Future efforts will require efficient xylose utilization, GX cleavage by a β-glucosidase, and/or a CBP with improved substrate specificity to overcome the negative impacts of xylose on CBP in cellobiose and xylose co-fermentation.
Collapse
Affiliation(s)
- Kulika Chomvong
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Vesna Kordić
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Xin Li
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Stefan Bauer
- Energy Biosciences Institute, University of California, Berkeley, CA, USA
| | - Abigail E Gillespie
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Suk-Jin Ha
- Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
- Department of Bioengineering and Technology, Kangwon National University, Chuncheon, Republic of Korea
| | - Eun Joong Oh
- Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Jonathan M Galazka
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL, USA
- Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Jamie H D Cate
- Department of Chemistry, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| |
Collapse
|
17
|
Purification and characterization of 1,3-β-D-glucan phosphorylase from Ochromonas danica. Biosci Biotechnol Biochem 2013; 77:1949-54. [PMID: 24018693 DOI: 10.1271/bbb.130411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
1,3-β-D-glucan phosphorylase (BGP) is an enzyme that catalyzes the reversible phosphorolysis of 1,3-β-glucosidic linkages to form α-D-glucose 1-phosphate (G1P). Here we report on the purification and characterization of BGP from Ochromonas danica (OdBGP). The purified enzyme preparation showed three bands (113, 118, and 124 kDa) on SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature were 5.5 and 25 °C-30 °C. OdBGP phosphorolysed laminaritriose, larger laminarioligosaccharides, and laminarin, but not laminaribiose. In the synthesis reaction, laminarin and laminarioligosaccharides served as good acceptors, but OdBGP did not act on glucose. Kinetic analysis indicated that the phosphorolysis reaction of OdBGP follows a sequential Bi Bi mechanism. The equilibrium of the enzymatic reaction indicated that OdBGP favors the reaction in the synthetic direction. Overnight incubation of OdBGP with laminaribiose and G1P resulted in the formation of precipitates, which were probably 1,3-β-glucans.
Collapse
|
18
|
Sawano T, Saburi W, Hamura K, Matsui H, Mori H. Characterization of Ruminococcus albus cellodextrin phosphorylase and identification of a key phenylalanine residue for acceptor specificity and affinity to the phosphate group. FEBS J 2013; 280:4463-73. [PMID: 23802549 DOI: 10.1111/febs.12408] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/12/2013] [Accepted: 06/24/2013] [Indexed: 11/28/2022]
Abstract
Ruminococcus albus has the ability to intracellularly degrade cello-oligosaccharides primarily via phosphorolysis. In this study, the enzymatic characteristics of R. albus cellodextrin phosphorylase (RaCDP), which is a member of glycoside hydrolase family 94, was investigated. RaCDP catalyzes the phosphorolysis of cellotriose through an ordered 'bi bi' mechanism in which cellotriose binds to RaCDP before inorganic phosphate, and then cellobiose and glucose 1-phosphate (Glc1P) are released in that order. Among the cello-oligosaccharides tested, RaCDP had the highest phosphorolytic and synthetic activities towards cellohexaose and cellopentaose, respectively. RaCDP successively transferred glucosyl residues from Glc1P to the growing cello-oligosaccharide chain, and insoluble cello-oligosaccharides comprising a mean of eight residues were produced. Sophorose, laminaribiose, β-1,4-xylobiose, β-1,4-mannobiose and cellobiitol served as acceptors for RaCDP. RaCDP had very low affinity for phosphate groups in both the phosphorolysis and synthesis directions. A sequence comparison revealed that RaCDP has Gln at position 646 where His is normally conserved in the phosphate binding sites of related enzymes. A Q646H mutant showed approximately twofold lower apparent K(m) values for inorganic phosphate and Glc1P than the wild-type. RaCDP has Phe at position 633 corresponding to Tyr and Val in the +1 subsites of cellobiose phosphorylase and N,N'-diacetylchitobiose phosphorylase, respectively. A F633Y mutant showed higher preference for cellobiose over β-1,4-mannobiose as an acceptor substrate in the synthetic reaction than the wild-type. Furthermore, the F633Y mutant showed 75- and 1100-fold lower apparent Km values for inorganic phosphate and Glc1P, respectively, in phosphorolysis and synthesis of cellotriose.
Collapse
Affiliation(s)
- Tatsuya Sawano
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | | | | | | | | |
Collapse
|
19
|
Hamura K, Saburi W, Matsui H, Mori H. Modulation of acceptor specificity of Ruminococcus albus cellobiose phosphorylase through site-directed mutagenesis. Carbohydr Res 2013; 379:21-5. [PMID: 23845516 DOI: 10.1016/j.carres.2013.06.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/11/2013] [Accepted: 06/12/2013] [Indexed: 11/30/2022]
Abstract
Cellobiose phosphorylase (EC 2.4.1.20, CBP) catalyzes the reversible phosphorolysis of cellobiose to α-D-glucose 1-phosphate (Glc1P) and d-glucose. Cys485, Tyr648, and Glu653 of CBP from Ruminococcus albus, situated at the +1 subsite, were mutated to modulate acceptor specificity. C485A, Y648F, and Y648V were active enough for analysis. Their acceptor specificities were compared with the wild type based on the apparent kinetic parameters determined in the presence of 10 mM Glc1P. C485A showed higher preference for D-glucosamine than the wild type. Apparent kcat/Km values of Y648F for D-mannose and 2-deoxy-D-glucose were 8.2- and 4.0-fold higher than those of the wild type, respectively. Y648V had synthetic activity toward N-acetyl-D-glucosamine, while the other variants did not. The oligosaccharide production in the presence of the same concentrations of wild type and each mutant was compared. C485A produced 4-O-β-D-glucopyranosyl-D-glucosamine from 10 mM Glc1P and D-glucosamine at a rate similar to the wild type. Y648F and Y648V produced 4-O-β-D-glucopyranosyl-D-mannose and 4-O-β-D-glucopyranosyl-N-acetyl-D-glucosamine much more rapidly than the wild type when D-mannose and N-acetyl-D-glucosamine were used as acceptors, respectively. After a 4h reaction, the amounts of 4-O-β-D-glucopyranosyl-D-mannose and 4-O-β-D-glucopyranosyl-N-acetyl-D-glucosamine produced by Y648F and Y648V were 5.9- and 12-fold higher than the wild type, respectively.
Collapse
Affiliation(s)
- Ken Hamura
- Research Faculty of Agriculture, Hokkaido University, Kita-ku, Sapporo, Japan
| | | | | | | |
Collapse
|
20
|
Kawahara R, Saburi W, Odaka R, Taguchi H, Ito S, Mori H, Matsui H. Metabolic mechanism of mannan in a ruminal bacterium, Ruminococcus albus, involving two mannoside phosphorylases and cellobiose 2-epimerase: discovery of a new carbohydrate phosphorylase, β-1,4-mannooligosaccharide phosphorylase. J Biol Chem 2012; 287:42389-99. [PMID: 23093406 DOI: 10.1074/jbc.m112.390336] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ruminococcus albus is a typical ruminal bacterium digesting cellulose and hemicellulose. Cellobiose 2-epimerase (CE; EC 5.1.3.11), which converts cellobiose to 4-O-β-D-glucosyl-D-mannose, is a particularly unique enzyme in R. albus, but its physiological function is unclear. Recently, a new metabolic pathway of mannan involving CE was postulated for another CE-producing bacterium, Bacteroides fragilis. In this pathway, β-1,4-mannobiose is epimerized to 4-O-β-D-mannosyl-D-glucose (Man-Glc) by CE, and Man-Glc is phosphorolyzed to α-D-mannosyl 1-phosphate (Man1P) and D-glucose by Man-Glc phosphorylase (MP; EC 2.4.1.281). Ruminococcus albus NE1 showed intracellular MP activity, and two MP isozymes, RaMP1 and RaMP2, were obtained from the cell-free extract. These enzymes were highly specific for the mannosyl residue at the non-reducing end of the substrate and catalyzed the phosphorolysis and synthesis of Man-Glc through a sequential Bi Bi mechanism. In a synthetic reaction, RaMP1 showed high activity only toward D-glucose and 6-deoxy-D-glucose in the presence of Man1P, whereas RaMP2 showed acceptor specificity significantly different from RaMP1. RaMP2 acted on D-glucose derivatives at the C2- and C3-positions, including deoxy- and deoxyfluoro-analogues and epimers, but not on those substituted at the C6-position. Furthermore, RaMP2 had high synthetic activity toward the following oligosaccharides: β-linked glucobioses, maltose, N,N'-diacetylchitobiose, and β-1,4-mannooligosaccharides. Particularly, β-1,4-mannooligosaccharides served as significantly better acceptor substrates for RaMP2 than D-glucose. In the phosphorolytic reactions, RaMP2 had weak activity toward β-1,4-mannobiose but efficiently degraded β-1,4-mannooligosaccharides longer than β-1,4-mannobiose. Consequently, RaMP2 is thought to catalyze the phosphorolysis of β-1,4-mannooligosaccharides longer than β-1,4-mannobiose to produce Man1P and β-1,4-mannobiose.
Collapse
Affiliation(s)
- Ryosuke Kawahara
- Research Faculty of Agriculture, Hokkaido University, N-9, W-9, Sapporo 060-8589, Japan
| | | | | | | | | | | | | |
Collapse
|
21
|
Nihira T, Saito Y, Kitaoka M, Nishimoto M, Otsubo K, Nakai H. Characterization of a laminaribiose phosphorylase from Acholeplasma laidlawii PG-8A and production of 1,3-β-D-glucosyl disaccharides. Carbohydr Res 2012; 361:49-54. [PMID: 22982171 DOI: 10.1016/j.carres.2012.08.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/06/2012] [Accepted: 08/13/2012] [Indexed: 11/18/2022]
Abstract
We identified a glycoside hydrolase family 94 homolog (ACL0729) from Acholeplasma laidlawii PG-8A as a laminaribiose (1,3-β-D-glucobiose) phosphorylase (EC 2.4.1.31). The recombinant ACL0729 produced in Escherichia coli catalyzed phosphorolysis of laminaribiose with inversion of the anomeric configuration in a typical sequential bi bi mechanism releasing α-D-glucose 1-phosphate and D-glucose. Laminaritriose (1,3-β-D-glucotriose) was not an efficient substrate for ACL0729. The phosphorolysis is reversible, enabling synthesis of 1,3-β-D-glucosyl disaccharides by reverse phosphorolysis with strict regioselectivity from α-D-glucose 1-phosphate as the donor and suitable monosaccharide acceptors (D-glucose, 2-deoxy-D-arabino-hexopyranose, D-xylose, D-glucuronic acid, 1,5-anhydro-D-glucitol, and D-mannose) with C-3 and C-4 equatorial hydroxyl groups. The D-glucose and 2-deoxy-D-arabino-hexopyranose caused significantly strong competitive substrate inhibition compared with other glucobiose phosphorylases reported, in which the acceptor competitively inhibited the binding of the donor substrate. By contrast, none of the examined disaccharides served as acceptor in the synthetic reaction.
Collapse
Affiliation(s)
- Takanori Nihira
- Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | | | | | | | | | | |
Collapse
|