1
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Hansen AL, Theisen FF, Crehuet R, Marcos E, Aghajari N, Willemoës M. Carving out a Glycoside Hydrolase Active Site for Incorporation into a New Protein Scaffold Using Deep Network Hallucination. ACS Synth Biol 2024; 13:862-875. [PMID: 38357862 PMCID: PMC10949244 DOI: 10.1021/acssynbio.3c00674] [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: 11/08/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/16/2024]
Abstract
Enzymes are indispensable biocatalysts for numerous industrial applications, yet stability, selectivity, and restricted substrate recognition present limitations for their use. Despite the importance of enzyme engineering in overcoming these limitations, success is often challenged by the intricate architecture of enzymes derived from natural sources. Recent advances in computational methods have enabled the de novo design of simplified scaffolds with specific functional sites. Such scaffolds may be advantageous as platforms for enzyme engineering. Here, we present a strategy for the de novo design of a simplified scaffold of an endo-α-N-acetylgalactosaminidase active site, a glycoside hydrolase from the GH101 enzyme family. Using a combination of trRosetta hallucination, iterative cycles of deep-learning-based structure prediction, and ProteinMPNN sequence design, we designed proteins with 290 amino acids incorporating the active site while reducing the molecular weight by over 100 kDa compared to the initial endo-α-N-acetylgalactosaminidase. Of 11 tested designs, six were expressed as soluble monomers, displaying similar or increased thermostabilities compared to the natural enzyme. Despite lacking detectable enzymatic activity, the experimentally determined crystal structures of a representative design closely matched the design with a root-mean-square deviation of 1.0 Å, with most catalytically important side chains within 2.0 Å. The results highlight the potential of scaffold hallucination in designing proteins that may serve as a foundation for subsequent enzyme engineering.
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Affiliation(s)
- Anders Lønstrup Hansen
- The
Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular
Sciences, Department of Biology, University
of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | - Frederik Friis Theisen
- The
Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular
Sciences, Department of Biology, University
of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | - Ramon Crehuet
- Institute
for Advanced Chemistry of Catalonia (IQAC), CSIC, Carrer Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Enrique Marcos
- Protein
Design and Modeling Lab, Department of Structural and Molecular Biology, Molecular Biology Institute of Barcelona (IBMB), CSIC, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Nushin Aghajari
- Molecular
Microbiology and Structural Biochemistry, CNRS, University of Lyon1, UMR5086, 7 Passage du Vercors, F-69367 Lyon CEDEX 07, France
| | - Martin Willemoës
- The
Linderstrøm-Lang Centre for Protein Science, Section for Biomolecular
Sciences, Department of Biology, University
of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
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2
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Choi A, Dong K, Williams E, Pia L, Batagower J, Bending P, Shin I, Peters DI, Kaspar JR. Human saliva modifies growth, biofilm architecture, and competitive behaviors of oral streptococci. mSphere 2024; 9:e0077123. [PMID: 38319113 PMCID: PMC10900908 DOI: 10.1128/msphere.00771-23] [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: 12/12/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
The bacteria within supragingival biofilms participate in complex exchanges with other microbes inhabiting the same niche. One example is the mutans group streptococci (Streptococcus mutans), implicated in the development of tooth decay, and other health-associated commensal streptococci species. Previously, our group transcriptomically characterized intermicrobial interactions between S. mutans and several species of oral bacteria. However, these experiments were carried out in a medium without human saliva. To better mimic their natural environment, we first evaluated how inclusion of saliva affected growth and biofilm formation of eight Streptococcus species individually and found saliva to positively benefit growth rates while negatively influencing biofilm biomass accumulation and altering spatial arrangement. These results carried over during evaluation of 29 saliva-derived isolates of various species. Surprisingly, we also found that addition of saliva increased the competitive behaviors of S. mutans in coculture competitions against commensal streptococci that led to increases in biofilm microcolony volumes. Through transcriptomically characterizing mono- and cocultures of S. mutans and Streptococcus oralis with and without saliva, we determined that each species developed a nutritional niche under mixed-species growth, with S. mutans upregulating carbohydrate uptake and utilization pathways while S. oralis upregulated genome features related to peptide uptake and glycan foraging. S. mutans also upregulated genes involved in oxidative stress tolerance, particularly manganese uptake, which we could artificially manipulate by supplementing in manganese leading to an advantage over its opponent. Our report highlights observable changes in microbial behaviors through leveraging environmental- and host-supplied resources over their competitors. IMPORTANCE Dental caries (tooth decay) is the most prevalent disease for both children and adults nationwide. Caries are initiated from demineralization of the enamel due to organic acid production through the metabolic activity of oral bacteria growing in biofilm communities attached to the tooth's surface. Mutans group streptococci are closely associated with caries development and initiation of the cariogenic cycle, which decreases the amount of acid-sensitive, health-associated commensal bacteria while selecting for aciduric and acidogenic species that then further drives the disease process. Defining the exchanges that occur between mutans group streptococci and oral commensals in a condition that closely mimics their natural environment is of critical need toward identifying factors that can influence odontopathogen establishment, persistence, and outgrowth. The goal of our research is to develop strategies, potentially through manipulation of microbial interactions characterized here, that prevent the emergence of mutans group streptococci while keeping the protective flora intact.
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Affiliation(s)
- Allen Choi
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Kevin Dong
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Emily Williams
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Lindsey Pia
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Jordan Batagower
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Paige Bending
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Iris Shin
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Daniel I Peters
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
| | - Justin R Kaspar
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio, USA
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3
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Choi A, Dong K, Williams E, Pia L, Batagower J, Bending P, Shin I, Peters DI, Kaspar JR. Human Saliva Modifies Growth, Biofilm Architecture and Competitive Behaviors of Oral Streptococci. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554151. [PMID: 37662325 PMCID: PMC10473590 DOI: 10.1101/2023.08.21.554151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The bacteria within supragingival biofilms participate in complex exchanges with other microbes inhabiting the same niche. One example are the mutans group streptococci (Streptococcus mutans), implicated in the development of tooth decay, and other health-associated commensal streptococci species. Previously, our group transcriptomically characterized intermicrobial interactions between S. mutans and several species of oral bacteria. However, these experiments were carried out in a medium that was absent of human saliva. To better mimic their natural environment, we first evaluated how inclusion of saliva affected growth and biofilm formation of eight streptococci species individually, and found saliva to positively benefit growth rates while negatively influencing biomass accumulation and altering spatial arrangement. These results carried over during evaluation of 29 saliva-derived isolates of various species. Surprisingly, we also found that addition of saliva increased the competitive behaviors of S. mutans in coculture competitions against commensal streptococci that led to increases in biofilm microcolony volumes. Through transcriptomically characterizing mono- and cocultures of S. mutans and Streptococcus oralis with and without saliva, we determined that each species developed a nutritional niche under mixed-species growth, with S. mutans upregulating carbohydrate uptake and utilization pathways while S. oralis upregulated genome features related to peptide uptake and glycan foraging. S. mutans also upregulated genes involved in oxidative stress tolerance, particularly manganese uptake, which we could artificially manipulate by supplementing in manganese to give it an advantage over its opponent. Our report highlights observable changes in microbial behaviors via leveraging environmental- and host-supplied resources over their competitors.
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Affiliation(s)
- Allen Choi
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Kevin Dong
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Emily Williams
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Lindsey Pia
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Jordan Batagower
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Paige Bending
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Iris Shin
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Daniel I Peters
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
| | - Justin R Kaspar
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, Ohio
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4
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Engineering Bifidobacterium longum Endo-α-N-acetylgalactosaminidase for Neu5Acα2-3Galβ1-3GalNAc reactivity on Fetuin. Arch Biochem Biophys 2022; 725:109280. [DOI: 10.1016/j.abb.2022.109280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/13/2022] [Accepted: 05/04/2022] [Indexed: 11/19/2022]
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5
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Hansen AL, Koivisto JM, Simonsen S, Dong Z, Crehuet R, Hansen DK, Willemoës M. Identification of a Catalytic Nucleophile-Activating Network in the endo -α -N-Acetylgalactosaminidase of Family GH101. Biochemistry 2021; 60:3398-3407. [PMID: 34694774 DOI: 10.1021/acs.biochem.1c00596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bifidobacterium longum endo-α-N-acetylgalactosaminidase (GH101), EngBF, is highly specific toward the mucin Core 1 glycan, Galβ1-3GalNAc. Apart from the side chains involved in the retaining mechanism of EngBF, Asp-682 is important for the activity. In the crystal structures of both EngBF and EngSP (from Streptococcus pneumoniae), we identified a conserved water molecule in proximity to Asp-682 and the homologue residue in EngSP. The water molecule also coordinates the catalytic nucleophile and three other residues conserved in GH101 enzymes; in EngBF, these residues are His-685, His-718, and Asn-720. With casein-glycomacropeptide as the substrate, the importance of Asp-682 was confirmed by the lack of a detectable activity for the D682N enzyme. The enzyme variants, H685A, H718A, H685Q, and H718Q, all displayed only a modestly reduction in kcat of up to 15 fold for the H718A variant. However, the double-substituted variants, H685A/H718A and H685Q/H718Q, had a greatly reduced kcat value by about 200 fold compared to that of wild-type EngBF. With the synthetic substrate, Galβ(1-3)GalNAcα1-para-nitrophenol, kcat of the double-substituted variants was only up to 30-fold reduced and was found to increase with pH. Compared to the pre-steady-state kinetics of wild-type EngBF, a burst of about the size of the enzyme concentration was absent with the double-substituted EngBF variants, indicating that the nucleophilic attack had become at least as slow as the hydrolysis of the enzyme intermediate. Together, the results indicate that not only Asp-682 but also the entire conserved network of His-685, His-718, and what we suggest is a catalytic water molecule is important in the activation of the catalytic nucleophile.
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Affiliation(s)
- Anders Lønstrup Hansen
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Johanna M Koivisto
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Signe Simonsen
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Zehui Dong
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Ramon Crehuet
- CSIC-Institute for Advanced Chemistry of Catalonia (IQAC), c/ Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Dennis K Hansen
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Martin Willemoës
- Linderstrøm-Lang Centre, Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
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6
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Wardman JF, Rahfeld P, Liu F, Morgan-Lang C, Sim L, Hallam SJ, Withers SG. Discovery and Development of Promiscuous O-Glycan Hydrolases for Removal of Intact Sialyl T-Antigen. ACS Chem Biol 2021; 16:2004-2015. [PMID: 34309358 DOI: 10.1021/acschembio.1c00316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Mucin-type O-glycosylation (O-glycosylation) is a common post-translational modification that confers distinct biophysical properties to proteins and plays crucial roles in intercellular signaling. Yet, despite the importance of O-glycans, relatively few tools exist for their analysis and modification. In particular, there is a need for enzymes that can cleave the wide range of O-glycan structures found on protein surfaces, to facilitate glycan profiling and editing. Through functional metagenomic screening of the human gut microbiome, we discovered endo-O-glycan hydrolases from CAZy family GH101 that are capable of slowly cleaving the intact sialyl T-antigen trisaccharide (a ubiquitous O-glycan structure in humans) in addition to their primary activity against the T-antigen disaccharide. We then further explored this sequence space through phylogenetic profiling and analysis of representative enzymes, revealing large differences in the levels of this promiscuous activity between enzymes within the family. Through structural and sequence analysis, we identified active site residues that modulate specificity. Through subsequent rational protein engineering, we improved the activity of an enzyme identified by phylogenetic profiling sufficiently that substantial removal of the intact sialyl T-antigen from proteins could be readily achieved. Our best sialyl T-antigen hydrolase mutant, SpGH101 Q868G, is further shown to function on a number of proteins, tissues, and cells. Access to this enzyme opens up improved methodologies for unraveling the glycan code.
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Affiliation(s)
- Jacob F. Wardman
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Peter Rahfeld
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Feng Liu
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Connor Morgan-Lang
- Graduate Program in Bioinformatics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Lyann Sim
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Steven J. Hallam
- Graduate Program in Bioinformatics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Genome Science and Technology Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia V6T 1Z4, Canada
- Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- ECOSCOPE Training Program, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Stephen G. Withers
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Genome Science and Technology Program, University of British Columbia, 2329 West Mall, Vancouver, British Columbia V6T 1Z4, Canada
- ECOSCOPE Training Program, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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7
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Kulinich A, Wang Q, Duan XC, Lyu YM, Zhang XY, Awad FN, Liu L, Voglmeir J. Biochemical characterization of the endo-α-N-acetylgalactosaminidase pool of the human gut symbiont Tyzzerella nexilis. Carbohydr Res 2020; 490:107962. [PMID: 32169671 DOI: 10.1016/j.carres.2020.107962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/18/2020] [Accepted: 02/22/2020] [Indexed: 02/07/2023]
Abstract
Three large (2084-, 984-, and 2104-amino acids) endo-α-N-acetylgalactosaminidase candidate genes from the commensal human gut bacterium Tyzzerella nexilis were successfully cloned and subsequently expressed in Escherichia coli. Activity tests of the purified proteins revealed that two of the candidate genes (Tn0153 and Tn2105) were able to hydrolyze the disaccharide unit from Galβ1-3GalNAc-α-pNP. The biochemical characterization revealed optimum pH conditions of 4.0 for both enzymes and temperature optima of 50 °C. The addition of 2-mercaptoethanol, Triton X-100 and urea had only minor effects on the activity of the enzymes, and the addition of imidazole and sodium dodecyl sulfate led to a significant reduction of the enzymes' activities. A mutational study identified and confirmed the role of the catalytically significant amino acids. The present study describes the first functional characterization of members of the GH101 family from this human gut symbiont.
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Affiliation(s)
- Anna Kulinich
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Qian Wang
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Xu-Chu Duan
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Yong-Mei Lyu
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Xiao-Yang Zhang
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Faisal Nureldin Awad
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China
| | - Li Liu
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
| | - Josef Voglmeir
- Glycomics and Glycan Bioengineering Research Center (GGBRC), College of Food Science and Technology, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
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8
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Steady state kinetic analysis of O-linked GalNAc glycan release catalyzed by endo-α-N-acetylgalactosaminidase. Carbohydr Res 2019; 480:54-60. [DOI: 10.1016/j.carres.2019.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 11/17/2022]
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9
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Hobbs JK, Pluvinage B, Boraston AB. Glycan-metabolizing enzymes in microbe-host interactions: the Streptococcus pneumoniae paradigm. FEBS Lett 2018; 592:3865-3897. [PMID: 29608212 DOI: 10.1002/1873-3468.13045] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 12/31/2022]
Abstract
Streptococcus pneumoniae is a frequent colonizer of the upper airways; however, it is also an accomplished pathogen capable of causing life-threatening diseases. To colonize and cause invasive disease, this bacterium relies on a complex array of factors to mediate the host-bacterium interaction. The respiratory tract is rich in functionally important glycoconjugates that display a vast range of glycans, and, thus, a key component of the pneumococcus-host interaction involves an arsenal of bacterial carbohydrate-active enzymes to depolymerize these glycans and carbohydrate transporters to import the products. Through the destruction of host glycans, the glycan-specific metabolic machinery deployed by S. pneumoniae plays a variety of roles in the host-pathogen interaction. Here, we review the processing and metabolism of the major host-derived glycans, including N- and O-linked glycans, Lewis and blood group antigens, proteoglycans, and glycogen, as well as some dietary glycans. We discuss the role of these metabolic pathways in the S. pneumoniae-host interaction, speculate on the potential of key enzymes within these pathways as therapeutic targets, and relate S. pneumoniae as a model system to glycan processing in other microbial pathogens.
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Affiliation(s)
- Joanne K Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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10
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Multiple exo-glycosidases in human serum as detected with the substrate DNP-α-GalNAc. I. A new assay for lysosomal α- N-acetylgalactosaminidase. BBA CLINICAL 2017; 8:84-89. [PMID: 29062717 PMCID: PMC5645117 DOI: 10.1016/j.bbacli.2017.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper presents a new assay to determine the activity of the lysosomal enzyme α-N-acetylgalactosaminidase (Naga, EC 3.2.1.49) in human serum. It is based on the use of a new chromogenic substrate, DNP-α-GalNAc (2,4-dinitrophenyl-N-acetyl-α-D-galactosaminide) and is performed at pH 4.3 and 37 °C. This allows continuous monitoring of the absorbance of the released DNP. The assay can be performed with a standard spectrophotometer. Compared to established methods using an endpoint assay with MU-α-GalNAc (4-methylumbelliferyl-GalNAc), the present method gives a ca. 3-fold higher specific activity, while only one tenth of the serum concentration in the assay is required. Hence, the assay is at least 30-fold more sensitive than that with MU-α-GalNAc. The pH dependence of the reaction with DNP-α-GalNAc in the pH 3.5 to 6.5 region, while using 4% serum in the assay, shows only one peak around pH 4. This pH optimum is similar to that reported with MU-α-GalNAc. In the accompanying paper (S.P.J Albracht and J. Van Pelt (2017) Multiple exo-glycosidases in human serum as detected with the substrate DNP-α-GalNAc. II. Three α-N-acetylgalactosaminidase-like activities in the pH 5 to 8 region. BBA Clin. 8 (2017) 90-96), the method is used to show that, under special assay conditions, three more Naga-like activities can be uncovered in human serum.
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Key Words
- A380, optical absorbance at 380 nm
- DMF, dimethylformamide
- DMSO, dimethylsulphoxide
- DNP-α-GalNAc
- DNP-α-GalNAc, 2,4-dinitrophenyl-N-acetyl-α-D-galactosaminide
- DNPH, 2,4-dinitrophenol
- DNP−, 2,4-dinitrophenolate
- Gla, α-galactosidase A
- Lysosomes
- MU, 4-methylumbelliferone
- Naga
- Naga, α-N-acetylgalactosaminidase
- New assay
- RT, room temperature
- S.A., specific activity in nmol substrate per min per mL serum (nmol·min− 1·mL− 1), using 2 mM DNP-α-GalNAc
- Schindler disease
- pNP-α-GalNAc, para-nitrophenyl-α-GalNAc
- α-GalNAc, N-acetyl-α-D-galactosaminide
- α-N-acetylgalactosaminidase
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11
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Multiple exo-glycosidases in human serum as detected with the substrate DNP-α-GalNAc. II. Three α- N-acetylgalactosaminidase-like activities in the pH 5 to 8 region. BBA CLINICAL 2017; 8:90-96. [PMID: 29062718 PMCID: PMC5647467 DOI: 10.1016/j.bbacli.2017.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/12/2017] [Accepted: 09/12/2017] [Indexed: 11/23/2022]
Abstract
With the substrate DNP-α-GalNAc (2,4-dinitrophenyl-N-acetyl-α-d-galactosaminide) three α-N-acetylgalactosaminidase-like activities could be distinguished in serum, in addition to the classical lysosomal enzyme (Naga, EC 3.2.1.49, pH optimum at 4). Two activities had optima in the pH 5 to 6 region and one peaked around pH 8. Like the Naga activity at pH 4, the activity at pH 8 was detectable under standard assay conditions. However, the two activities in the pH 5 to 6 range were not readily apparent in such assays. They could be unmasked as separate activities only when low serum concentrations were used. Addition of 1% saturated ammonium sulphate to the assay medium stimulated these activities. All activities in the pH 5 to 8 range decreased with increasing serum concentration in the assay, suggesting the presence of endogenous inhibitors. The activities between pH 5 and 6 might be similar to an activity described in 1996, which was considerably elevated in serum of patients with great variety of cancers (N. Yamamoto, V.R. Naraparaju, and S.O. Asbell (1996). Deglycosylation of serum vitamin D3-binding protein leads to immunosuppression in cancer patients. Cancer Res. 56, 2827-2811).
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Key Words
- A380, optical absorbance at 380 nm
- DMF, dimethylformamide
- DNP, 2,4-dinitrophenol
- DNP-α-GalNAc
- DNP-α-GalNAc, 2,4-dinitrophenyl-N-acetyl-α-d-galactosaminide
- General tumour marker
- Human serum
- MU, 4-methylumbelliferone
- Naga, α-N-acetylgalactosaminidase (EC 3.2.1.49)
- Naga6, the collective Naga-like activities in the pH 5 to 6 region
- Naga8, the Naga-like activity in the pH 6.5 to 8 region
- RT, room temperature
- S.A., specific activity in nmol per min per mL serum (nmol min− 1 mL− 1), using 2 mM DNP-α-GalNAc
- TM, tumour marker
- pNP-α-GalNAc, para-nitrophenyl-α-GalNAc
- α-GalNAc, N-acetyl-α-d-galactosaminide
- α-N-Acetylgalactosaminidase
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12
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Singh AK, Osman AS, Woodiga SA, White P, Mahan JD, King SJ. Defining the role of pneumococcal neuraminidases and O-glycosidase in pneumococcal haemolytic uraemic syndrome. J Med Microbiol 2016; 65:975-984. [PMID: 27469261 DOI: 10.1099/jmm.0.000322] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The host and bacterial factors that lead to development of pneumococcal haemolytic uraemic syndrome (pHUS) remain poorly defined; however, it is widely believed that pneumococcal exposure of the Thomsen-Friedenreich antigen (T-antigen) on host surfaces is a key step in pathogenesis. Two enzymatic activities encoded by pneumococci determine the level of T-antigen exposed. Neuraminidases cleave terminal sialic acid to expose the T-antigen which is subsequently cleaved by O-glycosidase Eng. While a handful of studies have examined the role of neuraminidases in T-antigen exposure, no studies have addressed the potential role of O-glycosidase. This study used 29 pHUS isolates from the USA and 31 serotype-matched controls. All isolates contained eng, and no significant correlation between enzymatic activity and disease state (pHUS and blood non-pHUS isolates) was observed. A prior study from Taiwan suggested that neuraminidase NanC contributes to the development of pHUS. However, we observed no difference in nanC distribution. Similar to previously published data, we found no significant correlation between neuraminidase activity and disease state. Accurate quantification of these enzymatic activities from bacteria grown in whole blood is currently impossible, but we confirmed that there were no significant correlations between disease state and neuraminidase and O-glycosidase transcript levels after incubation in blood. Genomic sequencing of six pHUS isolates did not identify any genetic elements possibly contributing to haemolytic uraemic syndrome. These findings support the hypothesis that while exposure of T-antigen may be an important step in disease pathogenesis, host factors likely play a substantial role in determining which individuals develop haemolytic uraemic syndrome after pneumococcal invasive disease.
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Affiliation(s)
- Anirudh K Singh
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Amin S Osman
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Shireen A Woodiga
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Peter White
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, Ohio State University College of Medicine, Columbus, OH, USA
| | - John D Mahan
- Department of Pediatrics, Ohio State University College of Medicine, Columbus, OH, USA.,Department of Nephrology, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Samantha J King
- Center for Microbial Pathogenesis, Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, Ohio State University College of Medicine, Columbus, OH, USA
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13
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Gregg KJ, Suits MDL, Deng L, Vocadlo DJ, Boraston AB. Structural Analysis of a Family 101 Glycoside Hydrolase in Complex with Carbohydrates Reveals Insights into Its Mechanism. J Biol Chem 2015; 290:25657-69. [PMID: 26304114 DOI: 10.1074/jbc.m115.680470] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 11/06/2022] Open
Abstract
O-Linked glycosylation is one of the most abundant post-translational modifications of proteins. Within the secretory pathway of higher eukaryotes, the core of these glycans is frequently an N-acetylgalactosamine residue that is α-linked to serine or threonine residues. Glycoside hydrolases in family 101 are presently the only known enzymes to be able to hydrolyze this glycosidic linkage. Here we determine the high-resolution structures of the catalytic domain comprising a fragment of GH101 from Streptococcus pneumoniae TIGR4, SpGH101, in the absence of carbohydrate, and in complex with reaction products, inhibitor, and substrate analogues. Upon substrate binding, a tryptophan lid (residues 724-WNW-726) closes on the substrate. The closing of this lid fully engages the substrate in the active site with Asp-764 positioned directly beneath C1 of the sugar residue bound within the -1 subsite, consistent with its proposed role as the catalytic nucleophile. In all of the bound forms of the enzyme, however, the proposed catalytic acid/base residue was found to be too distant from the glycosidic oxygen (>4.3 Å) to serve directly as a general catalytic acid/base residue and thereby facilitate cleavage of the glycosidic bond. These same complexes, however, revealed a structurally conserved water molecule positioned between the catalytic acid/base and the glycosidic oxygen. On the basis of these structural observations we propose a new variation of the retaining glycoside hydrolase mechanism wherein the intervening water molecule enables a Grotthuss proton shuttle between Glu-796 and the glycosidic oxygen, permitting this residue to serve as the general acid/base catalytic residue.
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Affiliation(s)
- Katie J Gregg
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
| | - Michael D L Suits
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
| | - Lehua Deng
- the Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - David J Vocadlo
- the Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Alisdair B Boraston
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
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14
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Glawar AFG, Best D, Ayers BJ, Miyauchi S, Nakagawa S, Aguilar-Moncayo M, García Fernández JM, Ortiz Mellet C, Crabtree EV, Butters TD, Wilson FX, Kato A, Fleet GWJ. Scalable syntheses of both enantiomers of DNJNAc and DGJNAc from glucuronolactone: the effect of N-alkylation on hexosaminidase inhibition. Chemistry 2012; 18:9341-59. [PMID: 22736508 DOI: 10.1002/chem.201200110] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Indexed: 11/08/2022]
Abstract
The efficient scalable syntheses of 2-acetamido-1,2-dideoxy-D-galacto-nojirimycin (DGJNAc) and 2-acetamido-1,2-dideoxy-D-gluco-nojirimycin (DNJNAc) from D-glucuronolactone, as well as of their enantiomers from L-glucuronolactone, are reported. The evaluation of both enantiomers of DNJNAc and DGJNAc, along with their N-alkyl derivatives, as glycosidase inhibitors showed that DGJNAc and its N-alkyl derivatives were all inhibitors of α-GalNAcase but that none of the epimeric DNJNAc derivatives inhibited this enzyme. In contrast, both DGJNAc and DNJNAc, as well as their alkyl derivatives, were potent inhibitors of β-GlcNAcases and β-GalNAcases. Neither of the L-enantiomers showed any significant inhibition of any of the enzymes tested. Correlation of the in vitro inhibition with the cellular data, by using a free oligosaccharide analysis of the lysosomal enzyme inhibition, revealed the following structure-property relationship: hydrophobic side-chains preferentially promoted the intracellular access of iminosugars to those inhibitors with more-hydrophilic side-chain characteristics.
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Affiliation(s)
- Andreas F G Glawar
- Oxford Glycobiology Institute, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
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15
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Pérez-Dorado I, Galan-Bartual S, Hermoso JA. Pneumococcal surface proteins: when the whole is greater than the sum of its parts. Mol Oral Microbiol 2012; 27:221-45. [PMID: 22759309 DOI: 10.1111/j.2041-1014.2012.00655.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Surface-exposed proteins of pathogenic bacteria are considered as potential virulence factors through their direct contribution to host-pathogen interactions. Four families of surface proteins decorate the cell surface of the human pathogen Streptococcus pneumoniae. Besides lipoproteins and LPXTG proteins, also present in other gram-positive bacteria, the pneumococcus presents the choline-binding protein (CBP) family and the non-classical surface proteins (NCSPs). The CBPs present specific structural features that allow their anchorage to the cell envelope through non-covalent interaction with choline residues of lipoteichoic acid and teichoic acid. NCSP is an umbrella term for less characterized proteins displaying moonlighting functions on the pneumococcal surface that lack a leader peptide and membrane-anchor motif. Considering the unceasing evolution of microbial species under the selective pressure of antibiotic use, detailed understanding of the interaction between pathogen and the host cells is required for the development of novel therapeutic strategies to combat pneumococcal infections. This article reviews recent progress in the investigation of the three-dimensional structures of surface-exposed pneumococcal proteins. The modular nature of some of them produces a great versatility and sophistication of the virulence functions that, in most cases, cannot be deduced by the structural analysis of the isolated modules.
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Affiliation(s)
- I Pérez-Dorado
- Department of Crystallography and Structural Biology, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain
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Abstract
In the last decade, glycan microarrays have revolutionized the analysis of the specificity of glycan-binding proteins (GBPs), providing information that simultaneously illuminates the biology mediated by them and decodes the informational content of the glycome. Numerous methods have emerged for arraying glycans in a "chip" format, and glycan libraries have been assembled that address the diversity of the human glycome. Such arrays have been successfully used for analysis of GBPs, which mediate mammalian biology, host-pathogen interactions, and immune recognition of glycans relevant to vaccine production and cancer antigens. This review covers the development of glycan microarrays and applications that have provided insights into the roles of mammalian and microbial GBPs.
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Affiliation(s)
- Cory D Rillahan
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037, USA.
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17
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Hreggvidsson GO, Dobruchowska JM, Fridjonsson OH, Jonsson JO, Gerwig GJ, Aevarsson A, Kristjansson JK, Curti D, Redgwell RJ, Hansen CE, Kamerling JP, Debeche-Boukhit T, Suzuki N, Nawa D, Yamamoto K, Ju T, Xia B, Aryal RP, Wang W, Wang Y, Ding X, Mi R, He M, Cummings RD. Errata. Glycobiology 2011. [DOI: 10.1093/glycob/cwr035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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18
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Naumoff DG. GH101 family of glycoside hydrolases: subfamily structure and evolutionary connections with other families. J Bioinform Comput Biol 2010; 8:437-51. [PMID: 20556855 DOI: 10.1142/s0219720010004628] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 12/18/2009] [Accepted: 01/14/2010] [Indexed: 11/18/2022]
Abstract
The GH101 family is composed of endo-alpha-N-acetylgalactosaminidases and their homologues. Pairwise sequence comparison and phylogenetic analysis allowed us to distinguish five to six subfamilies in this family. Diverse domain structures were found among the family members. Usually they have five irreplaceable and some optional domains. Iterative screening of the protein database revealed an evolutionary relationship of the GH101 catalytic domain with glycoside hydrolase domains from GH13, GH31, and GH70 families. Among other homologous proteins we have found representatives of COG1649, as well as members of four new families of predicted glycoside hydrolases (GHL1-GHL4).
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Affiliation(s)
- Daniil G Naumoff
- Laboratory of Bioinformatics, State Institute for Genetics and Selection of Industrial Microorganisms, I-Dorozhny Proezd 1, Moscow 117545, Russia.
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Ju T, Xia B, Aryal RP, Wang W, Wang Y, Ding X, Mi R, He M, Cummings RD. A novel fluorescent assay for T-synthase activity. Glycobiology 2010; 21:352-62. [PMID: 20959392 DOI: 10.1093/glycob/cwq168] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Loss of T-synthase (uridine diphosphate galactose:N-acetylgalactosaminyl-α1-Ser/Thr β3galactosyltransferase), a key enzyme required for the formation of mucin-type core 1 O-glycans, is observed in several human diseases, including cancer, Tn syndrome and IgA nephropathy, but current methods to assay the enzyme use radioactive substrates and complicated isolation of the product. Here we report the development of a novel fluorescent assay to measure its activity in a variety of tumor cell lines. Deficiencies in T-synthase activity correlate with mutations in the gene encoding the molecular chaperone Cosmc that is required for folding the T-synthase. This new high-throughput assay allows for facile screening of tumor specimens and other biological material for T-synthase activity and could be used diagnostically.
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Affiliation(s)
- Tongzhong Ju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Best D, Chairatana P, Glawar AF, Crabtree E, Butters TD, Wilson FX, Yu CY, Wang WB, Jia YM, Adachi I, Kato A, Fleet GW. Synthesis of 2-acetamido-1,2-dideoxy-d-galacto-nojirimycin [DGJNAc] from d-glucuronolactone: the first sub-micromolar inhibitor of α-N-acetylgalactosaminidases. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.02.063] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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