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Zhang Z, Dong M, Zallot R, Blackburn GM, Wang N, Wang C, Chen L, Baumann P, Wu Z, Wang Z, Fan H, Roth C, Jin Y, He Y. Mechanistic and Structural Insights into the Specificity and Biological Functions of Bacterial Sulfoglycosidases. ACS Catal 2022. [DOI: 10.1021/acscatal.2c05405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Zhen Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Mochen Dong
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Rémi Zallot
- Institute of Life Sciences, Swansea University Medical School, Swansea SA2 8PP, U.K
| | - George Michael Blackburn
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, U.K
| | - Nini Wang
- Key Laboratory of Synthetic and Natural Functional Molecule, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Chengjian Wang
- Glycobiology and Glycotechnology Research Center, College of Food Science and Technology, Northwest University, Xi’an 710069, P. R. China
| | - Long Chen
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Patrick Baumann
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Zuyan Wu
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Zhongfu Wang
- Glycobiology and Glycotechnology Research Center, College of Food Science and Technology, Northwest University, Xi’an 710069, P. R. China
| | - Haiming Fan
- Key Laboratory of Synthetic and Natural Functional Molecule, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Christian Roth
- Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Arnimallee 22, 14195 Berlin, German
| | - Yi Jin
- School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K
| | - Yuan He
- Key Laboratory of Synthetic and Natural Functional Molecule, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
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Li CC, Yi H, Wang YM, Tang XY, Zhu YB, Song YJ, Zhao NL, Huang Q, Mou XY, Luo GH, Liu TG, Yang GL, Zeng YJ, Wang LJ, Tang H, Fan G, Bao R. Nucleotide binding as an allosteric regulatory mechanism for Akkermansia muciniphila β- N-acetylhexosaminidase Am2136. Gut Microbes 2022; 14:2143221. [PMID: 36394293 PMCID: PMC9673926 DOI: 10.1080/19490976.2022.2143221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
β-N-acetylhexosaminidases (EC3.2.1.52), which belong to the glycosyl hydrolase family GH20, are important enzymes for oligosaccharides modification. Numerous microbial β-N-acetylhexosaminidases have been investigated for applications in biology, biomedicine and biotechnology. Akkermansia muciniphila is an anaerobic intestinal commensal bacterium which possesses specific β-N-acetylhexosaminidases for gut mucosal layer colonization and mucin degradation. In this study, we assessed the in vitro mucin glycan cleavage activity of the A. muciniphila β-N-acetylhexosaminidase Am2136 and demonstrated its ability that hydrolyzing the β-linkages joining N-acetylglucosamine to a wide variety of aglycone residues, which indicated that Am2136 may be a generalist β-N-acetylhexosaminidase. Structural and enzyme activity assay experiments allowed us to probe the essential function of the inter-domain interactions in β23-β33. Importantly, we revealed that the hydrolysis activity of Am2136 was enhanced by nucleotides. We further speculated that this activation mechanism might be associated with the conformational motions between domain III and IV. To our knowledge, this is the first report of nucleotide effector regulated β-N-acetylhexosaminidase, to reveal its novel biological functions. These findings contribute to understanding the distinct properties within the GH20 family and lay a certain foundation to develop controllable glycan hydrolyzing catalysts.Abbreviations: OD600 - optical cell densities at 600 nm; LB - Luria-Bertani; IPTG - isopropyl β-D-1-thiogalactopyranoside; PMSF - phenylmethanesulfonyl fluoride; rmsd - root mean square deviation; GlcNAc - N-acetyl-β-D-glucosamine; GalNAc - N-acetyl-β-D-galactosamine; Gal - galactose.
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Affiliation(s)
- Chang-Cheng Li
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Huan Yi
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yan-Mei Wang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu, China
| | - Xin-Yue Tang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Yi-Bo Zhu
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Ying-Jie Song
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Ning-Lin Zhao
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Qin Huang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Xing-Yu Mou
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Gui-Hua Luo
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Tong-Gen Liu
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Gang-Long Yang
- School of Biotechnology, Jiangnan University, Chengdu, China
| | - Yu-Jiao Zeng
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Li-Jie Wang
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hong Tang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China,Hong Tang Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University. Chengdu. China
| | - Gang Fan
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China,Gang Fan State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine. Chengdu. China
| | - Rui Bao
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China,CONTACT Rui Bao
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Cuxart I, Coines J, Esquivias O, Faijes M, Planas A, Biarnés X, Rovira C. Enzymatic Hydrolysis of Human Milk Oligosaccharides. The Molecular Mechanism of Bifidobacterium Bifidum Lacto- N-biosidase. ACS Catal 2022; 12:4737-4743. [PMID: 35465242 PMCID: PMC9016705 DOI: 10.1021/acscatal.2c00309] [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: 01/18/2022] [Revised: 03/26/2022] [Indexed: 12/22/2022]
Abstract
![]()
Bifidobacterium
bifidum lacto-N-biosidase (LnbB)
is a critical enzyme for the degradation
of human milk oligosaccharides in the gut microbiota of breast-fed
infants. Guided by recent crystal structures, we unveil its molecular
mechanism of catalysis using QM/MM metadynamics. We show that the
oligosaccharide substrate follows 1S3/1,4B → [4E]‡ → 4C1/4H5 and 4C1/4H5 → [4E/4H5]‡ → 1,4B conformational itineraries for the two
successive reaction steps, with reaction free energy barriers in agreement
with experiments. The simulations also identify a critical histidine
(His263) that switches between two orientations to modulate the pKa of the acid/base residue, facilitating catalysis.
The reaction intermediate of LnbB is best depicted as an oxazolinium
ion, with a minor population of neutral oxazoline. The present study
sheds light on the processing of oligosaccharides of the early life
microbiota and will be useful for the engineering of LnbB and similar
glycosidases for biocatalysis.
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Affiliation(s)
- Irene Cuxart
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Joan Coines
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Oriol Esquivias
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
| | - Magda Faijes
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Xevi Biarnés
- Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica & IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08020 Barcelona, Spain
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The Role of Chitooligosaccharidolytic β- N-Acetylglucosamindase in the Molting and Wing Development of the Silkworm Bombyx mori. Int J Mol Sci 2022; 23:ijms23073850. [PMID: 35409210 PMCID: PMC8998872 DOI: 10.3390/ijms23073850] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/21/2022] [Accepted: 03/27/2022] [Indexed: 02/01/2023] Open
Abstract
The insect glycoside hydrolase family 20 β-N-acetylhexosaminidases (HEXs) are key enzymes involved in chitin degradation. In this study, nine HEX genes in Bombyx mori were identified by genome-wide analysis. Bioinformatic analysis based on the transcriptome database indicated that each gene had a distinct expression pattern. qRT-PCR was performed to detect the expression pattern of the chitooligosaccharidolytic β-N-acetylglucosaminidase (BmChiNAG). BmChiNAG was highly expressed in chitin-rich tissues, such as the epidermis. In the wing disc and epidermis, BmChiNAG has the highest expression level during the wandering stage. CRISPR/Cas9-mediated BmChiNAG deletion was used to study the function. In the BmChiNAG-knockout line, 39.2% of female heterozygotes had small and curly wings. The ultrastructure of a cross-section showed that the lack of BmChiNAG affected the stratification of the wing membrane and the formation of the correct wing vein structure. The molting process of the homozygotes was severely hindered during the larva to pupa transition. Epidermal sections showed that the endocuticle of the pupa was not degraded in the mutant. These results indicate that BmChiNAG is involved in chitin catabolism and plays an important role in the molting and wing development of the silkworm, which highlights the potential of BmChiNAG as a pest control target.
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Tegl G, Rahfeld P, Ostmann K, Hanson J, Withers SG. Discovery of β- N-acetylglucosaminidases from screening metagenomic libraries and their use as thioglycoligase mutants. Org Biomol Chem 2021; 19:9068-9075. [PMID: 34622263 DOI: 10.1039/d1ob01246k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
β-N-Acetylhexosaminidases (HexNAcases) are versatile biocatalysts that cleave terminal N-acetylhexosamine units from various glycoconjugates. Established strategies to generate glycoside-forming versions of the wild type enzymes rely on the mutation of their catalytic residues; however, successful examples of synthetically useful HexNAcase mutants are scarce. In order to expand the range of HexNAcases available as targets for enzyme engineering, we functionally screened a metagenomic library derived from a human gut microbiome. From a pool of hits, we characterized four of the more active candidates by sequence analysis and phylogenetic mapping, and found that they all belonged to CAZy family GH20. After detailed kinetic analysis and characterization of their substrate specificities, active site mutants were generated which resulted in the identification of two new thioglycoligases. BvHex E294A and AsHex E301A catalyzed glycosyl transfer to all three of the 3-, 4- and 6-thio-N-acetylglucosaminides (thio-GlcNAcs) that were tested. Both mutant enzymes also catalyzed glycosyl transfer to a cysteine-containing variant of the model peptide Tab1, with AsHex E301A also transferring GlcNAc onto a thiol-containing protein. This work illustrates how large scale functional screening of expressed gene libraries allows the relatively rapid development of useful new glycoside-forming mutants of HexNAcases, expanding the pool of biocatalysts for carbohydrate synthesis.
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Affiliation(s)
- Gregor Tegl
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
| | - Peter Rahfeld
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
| | - Katharina Ostmann
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
| | - John Hanson
- Department of Chemistry, University of Puget Sound, Tacoma, USA
| | - Stephen G Withers
- Department of Chemistry, University of British Columbia, Vancouver, Canada.
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Activity of CcpA-Regulated GH18 Family Glycosyl Hydrolases That Contributes to Nutrient Acquisition and Fitness in Enterococcus faecalis. Infect Immun 2021; 89:e0034321. [PMID: 34424752 DOI: 10.1128/iai.00343-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The ability of Enterococcus faecalis to colonize host anatomical sites is dependent on its adaptive response to host conditions. Three glycosyl hydrolase gene clusters, each belonging to glycosyl hydrolase family 18 (GH18) (ef0114, ef0361, and ef2863), in E. faecalis were previously found to be upregulated under glucose-limiting conditions. The GH18 catalytic domain is present in proteins that are classified as either chitinases or β-1,4 endo-β-N-acetylglucosaminidases (ENGases) based on their β-1,4 endo-N-acetyl-β-d-glucosaminidase activity, and ENGase activity is commonly associated with cleaving N-linked glycoprotein, an abundant glycan structure on host epithelial surfaces. Here, we show that all three hydrolases are negatively regulated by the transcriptional regulator carbon catabolite protein A (CcpA). Additionally, we demonstrate that a constitutively active CcpA variant represses the expression of CcpA-regulated genes irrespective of glucose availability. Previous studies showed that the GH18 catalytic domains of EndoE (EF0114) and EfEndo18A (EF2863) were capable of deglycosylating RNase B, a model high-mannose-type glycoprotein. However, it remained uncertain which glycosidase is primarily responsible for the deglycosylation of high-mannose-type glycoproteins. In this study, we show by mutation analysis as well as a dose-dependent analysis of recombinant protein expression that EfEndo18A is primarily responsible for deglycosylating high-mannose glycoproteins and that the glycans removed by EfEndo18A support growth under nutrient-limiting conditions in vitro. In contrast, IgG is representative of a complex-type glycoprotein, and we demonstrate that the GH18 domain of EndoE is primarily responsible for the removal of this glycan decoration. Finally, our data highlight the combined contribution of glycosidases to the virulence of E. faecalis in vivo.
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Metabolism of Poly-β1,4- N-Acetylglucosamine Substrates and Importation of N-Acetylglucosamine and Glucosamine by Enterococcus faecalis. J Bacteriol 2021; 203:e0037121. [PMID: 34424034 DOI: 10.1128/jb.00371-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of Enterococcus faecalis to use a variety of carbon sources enables colonization at various anatomic sites within a mammalian host. N-Acetylglucosamine (GlcNAc) is one of the most abundant natural sugars and provides bacteria with a source of carbon and nitrogen when metabolized. N-Acetylglucosamine is also a component of bacterial peptidoglycan, further highlighting the significance of N-acetylglucosamine utilization. In this study, we show that CcpA-regulated enzymes are required for growth on the poly-β1,4-linked GlcNAc substrate, chitopentaose (β1,4-linked GlcNAc5). We also show that EF0114 (EndoE) is required for growth on chitobiose (β1,4-linked GlcNAc2) and that the GH20 domain of EndoE is required for the conversion of GlcNAc2 to N-acetylglucosamine. GlcNAc is transported into the cell via two separate phosphotransferase system (PTS) complexes, either the PTS IICBA encoded by ef1516 (nagE) or the Mpt glucose/mannose permease complex (MptBACD). The Mpt PTS is also the primary glucosamine transporter. In order for N-acetylglucosamine to be utilized as a carbon source, phosphorylated N-acetylglucosamine (GlcNAc-6-P) must be deacetylated, and here, we show that this activity is mediated by EF1317 (an N-acetylglucosamine-6-phosphate deacetylase; NagA homolog), as a deletion of ef1317 is unable to grow on GlcNAc as the carbon source. Deamination of glucosamine to fructose-6-phosphate is required for entry into glycolysis, and we show that growth on glucosamine is dependent on EF0466 (a glucosamine-6-phosphate deaminase; NagB homolog). Collectively, our data highlight the chitinolytic machinery required for breaking down exogenous chitinous substrates, as well as the uptake and cytosolic enzymes needed for metabolizing N-acetylglucosamine. IMPORTANCE Enterococcus faecalis causes life-threatening health care-associated infections in part due to its intrinsic and acquired antibiotic resistance, its ability to form biofilms, and its nutrient versatility. Alternative nutrient acquisition systems are key factors that contribute to enterococcal colonization at biologically unique host anatomic sites. Although E. faecalis can metabolize an array of carbon sources, little is known of how this bacterium acquires these secondary nutrient sources in mammalian hosts. Our research identifies the glycosidase machinery required for degrading exogenous chitinous substrates into N-acetylglucosamine monomers for transport and metabolism of one of the most abundant naturally occurring sugars, N-acetylglucosamine. Disrupting the function of this N-acetylglucosamine acquisition pathway may lead to new treatments against multidrug-resistant enterococcal infections.
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Meekrathok P, Bürger M, Porfetye AT, Kumsaoad S, Aunkham A, Vetter IR, Suginta W. Structural basis of chitin utilization by a GH20 β-N-acetylglucosaminidase from Vibrio campbellii strain ATCC BAA-1116. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2021; 77:674-689. [PMID: 33950022 PMCID: PMC8098473 DOI: 10.1107/s2059798321002771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 03/15/2021] [Indexed: 12/03/2022]
Abstract
Crystal structures of a GH20 β-N-acetylglucosaminidase from V. campbellii reveal substrate specificity in chitin utilization. Vibrio species play a crucial role in maintaining the carbon and nitrogen balance between the oceans and the land through their ability to employ chitin as a sole source of energy. This study describes the structural basis for the action of the GH20 β-N-acetylglucosaminidase (VhGlcNAcase) in chitin metabolism by Vibrio campbellii (formerly V. harveyi) strain ATCC BAA-1116. Crystal structures of wild-type VhGlcNAcase in the absence and presence of the sugar ligand, and of the unliganded D437A mutant, were determined. VhGlcNAcase contains three distinct domains: an N-terminal carbohydrate-binding domain linked to a small α+β domain and a C-terminal (β/α)8 catalytic domain. The active site of VhGlcNAcase has a narrow, shallow pocket that is suitable for accommodating a small chitooligosaccharide. VhGlcNAcase is a monomeric enzyme of 74 kDa, but its crystal structures show two molecules of enzyme per asymmetric unit, in which Gln16 at the dimeric interface of the first molecule partially blocks the entrance to the active site of the neighboring molecule. The GlcNAc unit observed in subsite −1 makes exclusive hydrogen bonds to the conserved residues Arg274, Tyr530, Asp532 and Glu584, while Trp487, Trp546, Trp582 and Trp505 form a hydrophobic wall around the −1 GlcNAc. The catalytic mutants D437A/N and E438A/Q exhibited a drastic loss of GlcNAcase activity, confirming the catalytic role of the acidic pair (Asp437–Glu438).
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Affiliation(s)
- Piyanat Meekrathok
- Biochemistry-Electrochemistry Research Unit, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - Marco Bürger
- Max-Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Arthur T Porfetye
- Max-Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Sawitree Kumsaoad
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), 555 Payupnai, Wangchan, Rayong 21210, Thailand
| | - Anuwat Aunkham
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), 555 Payupnai, Wangchan, Rayong 21210, Thailand
| | - Ingrid R Vetter
- Max-Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
| | - Wipa Suginta
- Biochemistry-Electrochemistry Research Unit, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
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Castejón-Vilatersana M, Faijes M, Planas A. Transglycosylation Activity of Engineered Bifidobacterium Lacto- N-Biosidase Mutants at Donor Subsites for Lacto- N-Tetraose Synthesis. Int J Mol Sci 2021; 22:3230. [PMID: 33810098 PMCID: PMC8004761 DOI: 10.3390/ijms22063230] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/14/2021] [Accepted: 03/19/2021] [Indexed: 01/11/2023] Open
Abstract
The health benefits of human milk oligosaccharides (HMOs) make them attractive targets as supplements for infant formula milks. However, HMO synthesis is still challenging and only two HMOs have been marketed. Engineering glycoside hydrolases into transglycosylases may provide biocatalytic routes to the synthesis of complex oligosaccharides. Lacto-N-biosidase from Bifidobacterium bifidum (LnbB) is a GH20 enzyme present in the gut microbiota of breast-fed infants that hydrolyzes lacto-N-tetraose (LNT), the core structure of the most abundant type I HMOs. Here we report a mutational study in the donor subsites of the substrate binding cleft with the aim of reducing hydrolytic activity and conferring transglycosylation activity for the synthesis of LNT from p-nitrophenyl β-lacto-N-bioside and lactose. As compared with the wt enzyme with negligible transglycosylation activity, mutants with residual hydrolase activity within 0.05% to 1.6% of the wild-type enzyme result in transglycosylating enzymes with LNT yields in the range of 10-30%. Mutations of Trp394, located in subsite -1 next to the catalytic residues, have a large impact on the transglycosylation/hydrolysis ratio, with W394F being the best mutant as a biocatalyst producing LNT at 32% yield. It is the first reported transglycosylating LnbB enzyme variant, amenable to further engineering for practical enzymatic synthesis of LNT.
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Affiliation(s)
| | - Magda Faijes
- Laboratory of Biochemistry, Institut Químic de Sarrià, University Ramon Llull, 08017 Barcelona, Spain;
| | - Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià, University Ramon Llull, 08017 Barcelona, Spain;
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10
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Agaricus bisporus Crude Extract: Characterization and Analytical Application. Molecules 2020; 25:molecules25245996. [PMID: 33352884 PMCID: PMC7765987 DOI: 10.3390/molecules25245996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/08/2020] [Accepted: 12/16/2020] [Indexed: 12/19/2022] Open
Abstract
In the present work crude Agaricus bisporus extract (ABE) has been prepared and characterized by its tyrosinase activity, protein composition and substrate specificity. The presence of mushroom tyrosinase (PPO3) in ABE has been confirmed using two-dimensional electrophoresis, followed by MALDI TOF/TOF MS-based analysis. GH27 alpha-glucosidases, GH47 alpha-mannosidases, GH20 hexosaminidases, and alkaline phosphatases have been also detected in ABE. ABE substrate specificity has been studied using 19 phenolic compounds: polyphenols (catechol, gallic, caffeic, chlorogenic, and ferulic acids, quercetin, rutin, dihydroquercetin, l-dihydroxyphenylalanine, resorcinol, propyl gallate) and monophenols (l-tyrosine, phenol, p-nitrophenol, o-nitrophenol, guaiacol, o-cresol, m-cresol, p-cresol). The comparison of ABE substrate specificity and affinity to the corresponding parameters of purified A. bisporus tyrosinase has revealed no major differences. The conditions for spectrophotometric determination have been chosen and the analytical procedures for determination of 1.4 × 10-4-1.0 × 10-3 M l-tyrosine, 3.1 × 10-6-1.0 × 10-4 M phenol, 5.4 × 10-5-1.0 × 10-3 M catechol, 8.5 × 10-5-1.0 × 10-3 M caffeic acid, 1.5 × 10-4-7.5 × 10-4 M chlorogenic acid, 6.8 × 10-5-1.0 × 10-3 M l-DOPA have been proposed. The procedures have been applied for the determination of l-tyrosine in food supplements, l-DOPA in synthetic serum, and phenol in waste water from the food manufacturing plant. Thus, we have demonstrated the possibility of using ABE as a substitute for tyrosinase in such analytical applications, as food supplements, medical and environmental analysis.
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Genomic and transcriptomic landscapes and evolutionary dynamics of molluscan glycoside hydrolase families with implications for algae-feeding biology. Comput Struct Biotechnol J 2020; 18:2744-2756. [PMID: 33101612 PMCID: PMC7560691 DOI: 10.1016/j.csbj.2020.09.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 01/03/2023] Open
Abstract
Genome-wide characterization of GH families is conducted for Mollusca. GH9, GH10, GH18 and GH20 families are remarkably expanded in molluscs. The wide adoption of CBMs likely facilitates the hydrolysis of polysaccharides. Hepatopancreas is the main organ for the prominent expression of GH families. Functional divergence of GH families possibly contributes to their adaptive roles.
The hydrolysis of sugar-containing compounds by glycoside hydrolases (GHs) plays essential roles in many major biological processes, but to date our systematic understanding of the functional diversity and evolution of GH families remains largely limited to a few well-studied terrestrial animals. Molluscs represent the largest marine phylum in the animal kingdom, and many of them are herbivorous that utilize algae as a main nutritional source, making them good subjects for studying the functional diversity and adaptive evolution of GH families. In the present study, we conducted genome-wide identification and functional and evolutionary analysis of all GH families across major molluscan lineages. We revealed that the remarkable expansion of the GH9, GH10, GH18 and GH20 families and the wide adoption of carbohydrate-binding modules in molluscan expanded GH families likely contributed to the efficient hydrolysis of marine algal polysaccharides and were involved in the consolidation of molluscan algae-feeding habits. Gene expression and network analysis revealed the hepatopancreas as the main organ for the prominent expression of approximately half of the GH families (well corresponding to the digestive roles of the hepatopancreas) and key or hub GHs in the coexpression gene network with potentially diverse functionalities. We also revealed the evolutionary signs of differential expansion and functional divergence of the GH family, which possibly contributed to lineage-specific adaptation. Systematic analysis of GH families at both genomic and transcriptomic levels provides important clues for understanding the functional divergence and evolution of GH gene families in molluscs in relation to their algae-feeding biology.
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Identification and Characterization of a β- N-Acetylhexosaminidase with a Biosynthetic Activity from the Marine Bacterium Paraglaciecola hydrolytica S66 T. Int J Mol Sci 2020; 21:ijms21020417. [PMID: 31936522 PMCID: PMC7014002 DOI: 10.3390/ijms21020417] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/04/2020] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
β-N-Acetylhexosaminidases are glycoside hydrolases (GHs) acting on N-acetylated carbohydrates and glycoproteins with the release of N-acetylhexosamines. Members of the family GH20 have been reported to catalyze the transfer of N-acetylglucosamine (GlcNAc) to an acceptor, i.e., the reverse of hydrolysis, thus representing an alternative to chemical oligosaccharide synthesis. Two putative GH20 β-N-acetylhexosaminidases, PhNah20A and PhNah20B, encoded by the marine bacterium Paraglaciecola hydrolytica S66T, are distantly related to previously characterized enzymes. Remarkably, PhNah20A was located by phylogenetic analysis outside clusters of other studied β-N-acetylhexosaminidases, in a unique position between bacterial and eukaryotic enzymes. We successfully produced recombinant PhNah20A showing optimum activity at pH 6.0 and 50 °C, hydrolysis of GlcNAc β-1,4 and β-1,3 linkages in chitobiose (GlcNAc)2 and GlcNAc-1,3-β-Gal-1,4-β-Glc (LNT2), a human milk oligosaccharide core structure. The kinetic parameters of PhNah20A for p-nitrophenyl-GlcNAc and p-nitrophenyl-GalNAc were highly similar: kcat/KM being 341 and 344 mM−1·s−1, respectively. PhNah20A was unstable in dilute solution, but retained full activity in the presence of 0.5% bovine serum albumin (BSA). PhNah20A catalyzed the formation of LNT2, the non-reducing trisaccharide β-Gal-1,4-β-Glc-1,1-β-GlcNAc, and in low amounts the β-1,2- or β-1,3-linked trisaccharide β-Gal-1,4(β-GlcNAc)-1,x-Glc by a transglycosylation of lactose using 2-methyl-(1,2-dideoxy-α-d-glucopyrano)-oxazoline (NAG-oxazoline) as the donor. PhNah20A is the first characterized member of a distinct subgroup within GH20 β-N-acetylhexosaminidases.
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Schmölzer K, Weingarten M, Baldenius K, Nidetzky B. Lacto-N-tetraose synthesis by wild-type and glycosynthase variants of the β-N-hexosaminidase from Bifidobacterium bifidum. Org Biomol Chem 2020; 17:5661-5665. [PMID: 31094393 DOI: 10.1039/c9ob00424f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Lacto-N-biose 1,2-oxazoline was prepared chemo-enzymatically and shown to be a donor substrate for β-1,3-glycosylation of lactose by the wild-type and glycosynthase variants (D320E, D320A, Y419F) of Bifidobacterium bifidum β-N-hexosaminidase. Lacto-N-tetraose, a core structure of human milk oligosaccharides, was formed in 20-60% yield of donor substrate (up to 8 mM product titre), depending on the degree of selectivity control by the enzyme used.
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Affiliation(s)
- Katharina Schmölzer
- Austrian Centre of Industrial Biotechnology (acib), Petersgasse 14, 8010 Graz, Austria.
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Jia D, Wang B, Li X, Peng W, Zhou J, Tan H, Tang J, Huang Z, Tan W, Gan B, Yang Z, Zhao J. Proteomic Analysis Revealed the Fruiting-Body Protein Profile of Auricularia polytricha. Curr Microbiol 2017; 74:943-951. [DOI: 10.1007/s00284-017-1268-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/19/2017] [Indexed: 02/07/2023]
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Robb M, Robb CS, Higgins MA, Hobbs JK, Paton JC, Boraston AB. A Second β-Hexosaminidase Encoded in the Streptococcus pneumoniae Genome Provides an Expanded Biochemical Ability to Degrade Host Glycans. J Biol Chem 2015; 290:30888-900. [PMID: 26491009 DOI: 10.1074/jbc.m115.688630] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/19/2022] Open
Abstract
An important facet of the interaction between the pathogen Streptococcus pneumoniae (pneumococcus) and its human host is the ability of this bacterium to process host glycans. To achieve cleavage of the glycosidic bonds in host glycans, S. pneumoniae deploys a wide array of glycoside hydrolases. Here, we identify and characterize a new family 20 glycoside hydrolase, GH20C, from S. pneumoniae. Recombinant GH20C possessed the ability to hydrolyze the β-linkages joining either N-acetylglucosamine or N-acetylgalactosamine to a wide variety of aglycon residues, thus revealing this enzyme to be a generalist N-acetylhexosaminidase in vitro. X-ray crystal structures were determined for GH20C in a ligand-free form, in complex with the N-acetylglucosamine and N-acetylgalactosamine products of catalysis and in complex with both gluco- and galacto-configured inhibitors O-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino N-phenyl carbamate (PUGNAc), O-(2-acetamido-2-deoxy-D-galactopyranosylidene)amino N-phenyl carbamate (GalPUGNAc), N-acetyl-D-glucosamine-thiazoline (NGT), and N-acetyl-D-galactosamine-thiazoline (GalNGT) at resolutions from 1.84 to 2.7 Å. These structures showed N-acetylglucosamine and N-acetylgalactosamine to be recognized via identical sets of molecular interactions. Although the same sets of interaction were maintained with the gluco- and galacto-configured inhibitors, the inhibition constants suggested preferred recognition of the axial O4 when an aglycon moiety was present (Ki for PUGNAc > GalPUGNAc) but preferred recognition of an equatorial O4 when the aglycon was absent (Ki for GalNGT > NGT). Overall, this study reveals GH20C to be another tool that is unique in the arsenal of S. pneumoniae and that it may implement the effort of the bacterium to utilize and/or destroy the wide array of host glycans that it may encounter.
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Affiliation(s)
- Melissa Robb
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6 and
| | - Craig S Robb
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6 and
| | - Melanie A Higgins
- the Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, South Australia 5005, Australia
| | - Joanne K Hobbs
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6 and
| | - James C Paton
- the Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, South Australia 5005, Australia
| | - Alisdair B Boraston
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada V8W 3P6 and
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