1
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Qiu X, Chong D, Fairbanks AJ. Selective Anomeric Acetylation of Unprotected Sugars with Acetic Anhydride in Water. Org Lett 2023; 25:1989-1993. [PMID: 36912487 DOI: 10.1021/acs.orglett.3c00584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Unprotected sugars are selectively acetylated simply by stirring in aqueous solution in the presence of acetic anhydride and a weak base such as sodium carbonate. The reaction is selective for acetylation of the anomeric hydroxyl group of mannose, 2-acetamido, and 2-deoxy sugars and can be performed on a large scale. Competitive intramolecular migration of the 1-O-acetate to the 2-hydroxyl group when these two substituents are cis causes over-reaction and the formation of product mixtures.
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Affiliation(s)
- Xin Qiu
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Daniel Chong
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Antony J Fairbanks
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
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2
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Mascherpa A, Ishii N, Tayagui A, Liu J, Sollogoub M, Fairbanks AJ. Lysosomal Targeting of β-Cyclodextrin. Chemistry 2023; 29:e202203252. [PMID: 36265126 PMCID: PMC10100462 DOI: 10.1002/chem.202203252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Indexed: 11/06/2022]
Abstract
β-Cyclodextrin (β-CD) and derivatives are approved therapeutics in >30 clinical settings. β-CDs have also shown promise as therapeutics for treatment of some lysosomal storage disorders, such as Niemann-Pick disease type C, and other disease states which involve metabolite accumulation in the lysosome. In these cases, β-CD activity relies on transport to the lysosome, wherein it can bind hydrophobic substrate and effect extraction. The post-translational attachment of N-glycans terminated in mannose-6-phosphate (M6P) residues is the predominant method by which lysosomal enzymes are targeted to the lysosome. In this work we covalently attach a synthetic biantennary bis-M6P-terminated N-glycan to β-CD and study the effect of the added glycans in a mammalian cell line. The formation of a host guest complex with a Cy5 fluorophore allows study of both cellular internalisation and transport to the lysosome by fluorescence microscopy. Results indicate that the rates of both internalisation and lysosomal transport are increased by the attachment of M6P-glycans to β-CD, indicating that M6P-glycan conjugation may improve the therapeutic effectiveness of β-CD for the treatment of disorders involving hydrophobic metabolite accumulation in the lysosome.
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Affiliation(s)
- Andrea Mascherpa
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Nozomii Ishii
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Ayelen Tayagui
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Jiang Liu
- Sorbonne University, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), UMR 8232, 4, place Jussieu, 75005, Paris, France
| | - Matthieu Sollogoub
- Sorbonne University, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), UMR 8232, 4, place Jussieu, 75005, Paris, France
| | - Antony J Fairbanks
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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3
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Qiu X, Garden AL, Fairbanks AJ. Protecting group free glycosylation: one-pot stereocontrolled access to 1,2- trans glycosides and (1→6)-linked disaccharides of 2-acetamido sugars. Chem Sci 2022; 13:4122-4130. [PMID: 35440979 PMCID: PMC8985506 DOI: 10.1039/d2sc00222a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/12/2022] [Indexed: 11/21/2022] Open
Abstract
Unprotected 2-acetamido sugars may be directly converted into their oxazolines using 2-chloro-1,3-dimethylimidazolinium chloride (DMC), and a suitable base, in aqueous solution. Freeze drying and acid catalysed reaction with an alcohol as solvent produces the corresponding 1,2-trans-glycosides in good yield. Alternatively, dissolution in an aprotic solvent system and acidic activation in the presence of an excess of an unprotected glycoside as a glycosyl acceptor, results in the stereoselective formation of the corresponding 1,2-trans linked disaccharides without any protecting group manipulations. Reactions using aryl glycosides as acceptors are completely regioselective, producing only the (1→6)-linked disaccharides.
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Affiliation(s)
- Xin Qiu
- School of Physical and Chemical Sciences, University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
| | - Anna L Garden
- Department of Chemistry, University of Otago Dunedin 9054 New Zealand.,The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington Wellington 6140 New Zealand
| | - Antony J Fairbanks
- School of Physical and Chemical Sciences, University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand .,Biomolecular Interaction Centre, University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
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4
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Lassé M, Stampfli AR, Orban T, Bothara RK, Gerrard JA, Fairbanks AJ, Pattinson NR, Dobson RCJ. Corrigendum to "Reaction dynamics and residue identification of haemoglobin modification by acrolein, a lipid-peroxidation by-product" [Biochimica et Biophysica Acta (BBA) - General Subjects Volume 1865, Issue 12, December 2021, 130013]. Biochim Biophys Acta Gen Subj 2022; 1866:130117. [PMID: 35249766 DOI: 10.1016/j.bbagen.2022.130117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Moritz Lassé
- Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Anja R Stampfli
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Thomas Orban
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Juliet A Gerrard
- Faculty of Science, Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Antony J Fairbanks
- Biomolecular Interaction Centre, and School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Neil R Pattinson
- Canterbury Scientific Ltd, 71 Whiteleigh Ave, Christchurch, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Biol21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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5
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Arif T, Currie MJ, Dobson RCJ, Newson HL, Poonthiyil V, Fairbanks AJ, North RA, Rendle PM. Synthesis of N-acetylmannosamine-6-phosphate derivatives to investigate the mechanism of N-acetylmannosamine-6-phosphate 2-epimerase. Carbohydr Res 2021; 510:108445. [PMID: 34607125 DOI: 10.1016/j.carres.2021.108445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/14/2021] [Accepted: 09/21/2021] [Indexed: 11/19/2022]
Abstract
The synthesis of analogues of natural enzyme substrates can be used to help deduce enzymatic mechanisms. N-Acetylmannosamine-6-phosphate 2-epimerase is an enzyme in the bacterial sialic acid catabolic pathway. To investigate whether the mechanism of this enzyme involves a re-protonation mechanism by the same neighbouring lysine that performed the deprotonation or a unique substrate-assisted proton displacement mechanism involving the substrate C5 hydroxyl, the syntheses of two analogues of the natural substrate, N-acetylmannosamine-6-phosphate, are described. In these novel analogues, the C5 hydroxyl has been replaced with a proton and a methyl ether respectively. As recently reported, Staphylococcus aureus N-acetylmannosamine-6-phosphate 2-epimerase was co-crystallized with these two compounds. The 5-deoxy variant bound to the enzyme active site in a different orientation to the natural substrate, while the 5-methoxy variant did not bind, adding to the evidence that this enzyme uses a substrate-assisted proton displacement mechanism. This mechanistic information may help in the design of potential antibacterial drug candidates.
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Affiliation(s)
- Tanzeel Arif
- Ferrier Research Institute, Victoria University of Wellington, PO Box 33-436, Lower Hutt, 5046, New Zealand
| | - Michael J Currie
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Renwick C J Dobson
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Harriet L Newson
- Ferrier Research Institute, Victoria University of Wellington, PO Box 33-436, Lower Hutt, 5046, New Zealand
| | - Vivek Poonthiyil
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Antony J Fairbanks
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Rachel A North
- University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Phillip M Rendle
- Ferrier Research Institute, Victoria University of Wellington, PO Box 33-436, Lower Hutt, 5046, New Zealand.
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6
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Currie MJ, Manjunath L, Horne CR, Rendle PM, Subramanian R, Friemann R, Fairbanks AJ, Muscroft-Taylor AC, North RA, Dobson RCJ. N-acetylmannosamine-6-phosphate 2-epimerase uses a novel substrate-assisted mechanism to catalyze amino sugar epimerization. J Biol Chem 2021; 297:101113. [PMID: 34437902 PMCID: PMC8482478 DOI: 10.1016/j.jbc.2021.101113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/14/2022] Open
Abstract
There are five known general catalytic mechanisms used by enzymes to catalyze carbohydrate epimerization. The amino sugar epimerase N-acetylmannosamine-6-phosphate 2-epimerase (NanE) has been proposed to use a deprotonation-reprotonation mechanism, with an essential catalytic lysine required for both steps. However, the structural determinants of this mechanism are not clearly established. We characterized NanE from Staphylococcus aureus using a new coupled assay to monitor NanE catalysis in real time and found that it has kinetic constants comparable with other species. The crystal structure of NanE from Staphylococcus aureus, which comprises a triosephosphate isomerase barrel fold with an unusual dimeric architecture, was solved with both natural and modified substrates. Using these substrate-bound structures, we identified the following active-site residues lining the cleft at the C-terminal end of the β-strands: Gln11, Arg40, Lys63, Asp124, Glu180, and Arg208, which were individually substituted and assessed in relation to the mechanism. From this, we re-evaluated the central role of Glu180 in this mechanism alongside the catalytic lysine. We observed that the substrate is bound in a conformation that ideally positions the C5 hydroxyl group to be activated by Glu180 and donate a proton to the C2 carbon. Taken together, we propose that NanE uses a novel substrate-assisted proton displacement mechanism to invert the C2 stereocenter of N-acetylmannosamine-6-phosphate. Our data and mechanistic interpretation may be useful in the development of inhibitors of this enzyme or in enzyme engineering to produce biocatalysts capable of changing the stereochemistry of molecules that are not amenable to synthetic methods.
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Affiliation(s)
- Michael J Currie
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Lavanyaa Manjunath
- Institute of Stem Cell Science and Regenerative Medicine, NCBS, Bangalore, Karnataka, India
| | - Christopher R Horne
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Phillip M Rendle
- Ferrier Research Institute, Victoria University of Wellington, Lower Hutt, New Zealand
| | - Ramaswamy Subramanian
- Institute of Stem Cell Science and Regenerative Medicine, NCBS, Bangalore, Karnataka, India
| | - Rosmarie Friemann
- Fujirebio Diagnostics, Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Antony J Fairbanks
- Biomolecular Interaction Centre and School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Andrew C Muscroft-Taylor
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Rachel A North
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia.
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7
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Lassé M, Stampfli AR, Orban T, Bothara RK, Gerrard JA, Fairbanks AJ, Pattinson NR, Dobson RCJ. Reaction dynamics and residue identification of haemoglobin modification by acrolein, a lipid-peroxidation by-product. Biochim Biophys Acta Gen Subj 2021; 1865:130013. [PMID: 34534644 DOI: 10.1016/j.bbagen.2021.130013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/06/2021] [Accepted: 09/10/2021] [Indexed: 11/15/2022]
Abstract
BACKGROUND Lipid hydroperoxides decompose to reactive aldehydes, such as acrolein. Measurement of oxidative stress markers in the clinic could improve risk stratification for patients. METHODS To aid the development of diagnostic oxidative stress markers, we defined the acrolein modifications of haemoglobin using mass spectrometry. RESULTS Acrolein modifications have little effect on the secondary structure of haemoglobin. They do not disrupt the quaternary structure, but instead promote crosslinked octamers. For acrolein modified haemoglobin the response to O2 binding is altered such that cooperativity is lost. Mass spectrometry experiments at a 1:1 acrolein:haemoglobin molar ratio demonstrate that the α-chain quickly forms an aza-Michael adduct (+56 Da), which then forms a more stable adduct, Nε-(3-methylpyridinium)lysine (MP-lysine, +76 Da) over 7 days. The β-chain remains relatively unchanged over the duration of the 7 days and the aza-Michael adduct is dominant. At 2:1 and 5:1 molar ratios the α-chain was consistently modified at K7, H20, H50, and the β-chain at C93 and H97 with the aza-Michael adduct. Beyond 5 h, an MP-adduct (+76 Da) was located predominantly at K7 of the α-chain, while an FDP-adduct (+94 Da) was observed at K95 of the β-chain. CONCLUSIONS We have generated qualitative evidence identifying the acrolein target sites on haemoglobin, a potential oxidative stress marker that is easily measured in circulation. GENERAL SIGNIFICANCE We provide data for the community to develop targeted mass spectrometric or immunometric assays for acrolein modified haemoglobin to further validate the potential of haemoglobin as an oxidative stress marker in patients .
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Affiliation(s)
- Moritz Lassé
- Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Anja R Stampfli
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Thomas Orban
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Juliet A Gerrard
- Faculty of Science, Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Antony J Fairbanks
- Biomolecular Interaction Centre, and School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Neil R Pattinson
- Canterbury Scientific Ltd, 71 Whiteleigh Ave, Christchurch, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Biol21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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8
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Fairbanks AJ. Applications of Shoda's reagent (DMC) and analogues for activation of the anomeric centre of unprotected carbohydrates. Carbohydr Res 2020; 499:108197. [PMID: 33256953 DOI: 10.1016/j.carres.2020.108197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 10/23/2022]
Abstract
2-Chloro-1,3-dimethylimidazolinium chloride (DMC, herein also referred to as Shoda's reagent) and its derivatives are useful for numerous synthetic transformations in which the anomeric centre of unprotected reducing sugars is selectively activated in aqueous solution. As such unprotected sugars can undergo anomeric substitution with a range of added nucleophiles, providing highly efficient routes to a range of glycosides and glycoconjugates without the need for traditional protecting group manipulations. This mini-review summarizes the development of DMC and some of its derivatives/analogues, and highlights recent applications for protecting group-free synthesis.
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Affiliation(s)
- Antony J Fairbanks
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand.
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9
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Wang X, Ashhurst AS, Dowman LJ, Watson EE, Li HY, Fairbanks AJ, Larance M, Kwan A, Payne RJ. Total Synthesis of Glycosylated Human Interferon-γ. Org Lett 2020; 22:6863-6867. [PMID: 32830985 DOI: 10.1021/acs.orglett.0c02401] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Interferon-γ (IFN-γ) is a glycoprotein that is responsible for orchestrating numerous critical immune induction and modulation processes and is used clinically for the treatment of a number of diseases. Herein, we describe the total chemical synthesis of homogeneously glycosylated variants of human IFN-γ using a tandem diselenide-selenoester ligation-deselenization strategy in the C- to N-terminal direction. The synthetic glycoproteins were successfully folded, and the structures and antiviral functions were assessed.
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Affiliation(s)
- Xiaoyi Wang
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Anneliese S Ashhurst
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.,School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia.,Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia
| | - Luke J Dowman
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Emma E Watson
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Henry Y Li
- School of Physical and Chemical Sciences, The University of Canterbury, Christchurch 8140, New Zealand
| | - Antony J Fairbanks
- School of Physical and Chemical Sciences, The University of Canterbury, Christchurch 8140, New Zealand
| | - Mark Larance
- Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ann Kwan
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Richard J Payne
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.,Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, https://cipps.org.au/
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10
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Affiliation(s)
- Xin Qiu
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Antony J. Fairbanks
- School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
- Biomolecular Interaction Center, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
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11
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Abstract
Activation of reducing sugars in aqueous solution using DMC and triethylamine in the presence of phenols allows direct stereoselective conversion to the corresponding 1,2-trans aryl glycosides without the need for any protecting groups.
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Affiliation(s)
- Xin Qiu
- Department of Chemistry
- University of Canterbury
- Christchurch
- New Zealand
| | - Antony J. Fairbanks
- Department of Chemistry
- University of Canterbury
- Christchurch
- New Zealand
- Biomolecular Interaction Centre
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12
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Abstract
M. Carmen Galan, Sabine Flitsch and Antony Fairbanks introduce the Organic & Biomolecular Chemistry themed collection on glycosylation: new methodologies and applications.
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Affiliation(s)
| | - Sabine L. Flitsch
- University of Manchester
- Manchester Institute of Biotechnology
- Manchester M1 7DN
- UK
| | - M. Carmen Galan
- School of Chemistry
- Cantock's Close
- University of Bristol
- Bristol BS8 1TS
- UK
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13
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Fairbanks AJ. Chemoenzymatic synthesis of glycoproteins. Curr Opin Chem Biol 2019; 53:9-15. [DOI: 10.1016/j.cbpa.2019.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 05/07/2019] [Accepted: 05/13/2019] [Indexed: 11/26/2022]
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14
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Paramasivam S, Fairbanks AJ. Rapid synthesis of N-glycan oxazolines from locust bean gum via the Lafont rearrangement. Carbohydr Res 2019; 477:11-19. [DOI: 10.1016/j.carres.2019.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/20/2019] [Indexed: 12/16/2022]
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15
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Fairbanks AJ. Meet the Board of ChemistryOpen: Antony J. Fairbanks. ChemistryOpen 2019; 8:188-189. [PMID: 30740293 PMCID: PMC6356170 DOI: 10.1002/open.201900020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Antony J. Fairbanks is a Professor in the Department of Chemistry at the University of Canterbury in New Zealand. The research of his group focuses on the broad areas of organic synthesis, particularly applied to carbohydrates. He currently serves as an active Editorial Board member for ChemistryOpen.
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Affiliation(s)
- Antony J. Fairbanks
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
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16
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Abstract
The endo-β-N-acetylglucosaminidases (ENGases) are an enzyme class (EC 3.2.1.96) produced by a range of organisms, ranging from bacteria, through fungi, to higher order species, including humans, comprising two-sub families of glycosidases which all cleave the chitobiose core of N-linked glycans. Synthetic applications of these enzymes, i.e. to catalyse the reverse of their natural hydrolytic mode of action, allow the attachment of N-glycans to a wide variety of substrates which contain an N-acetylglucosamine (GlcNAc) residue to act as an 'acceptor' handle. The use of N-glycan oxazolines, high energy intermediates on the hydrolytic pathway, as activated donors allows their high yielding attachment to almost any amino acid, peptide or protein that contains a GlcNAc residue as an acceptor. The synthetic effectiveness of these biocatalysts has been significantly increased by the production of mutant glycosynthases; enzymes which can still catalyse synthetic processes using oxazolines as donors, but which do not hydrolyse the reaction products. ENGase biocatalysts are now finding burgeoning application for the production of biologically active glycopeptides and glycoproteins, including therapeutic monoclonal antibodies (mAbs) for which the oligosaccharides have been remodelled to optimise effector functions.
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Affiliation(s)
- Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
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17
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Suthagar K, Fairbanks AJ. A new way to do an old reaction: highly efficient reduction of organic azides by sodium iodide in the presence of acidic ion exchange resin. Chem Commun (Camb) 2018; 53:713-715. [PMID: 27990533 DOI: 10.1039/c6cc08574a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Organic azides are readily reduced to the corresponding amines by treatment with sodium iodide in the presence of acidic ion exchange resin. The process, optimal when performed at 40 °C and 200 mbar pressure on a rotatory evaporator, is extremely efficient, clean, and tolerant of a variety of functional groups.
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Affiliation(s)
- Kajitha Suthagar
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand. and Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
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18
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Abstract
N-Glycan oxazolines have found widespread use as activated donor substrates for endo-β-N-acetylglucosaminidase (ENGase) enzymes, an important application that has correspondingly stimulated interest in their production, both by total synthesis and by semi-synthesis using oligosaccharides isolated from natural sources. Amongst the many synthetic approaches reported, the majority rely on the fabrication (either by total synthesis, or semi-synthesis from locust bean gum) of a key Manβ(1-4)GlcNAc disaccharide, which can then be elaborated at the 3- and 6-positions of the mannose unit using standard glycosylation chemistry. Early approaches subsequently relied on the Lewis acid catalysed conversion of peracetylated N-glycan oligosaccharides produced in this manner into their corresponding oxazolines, followed by global deprotection. However, a key breakthrough in the field has been the development by Shoda of 2-chloro-1,3-dimethylimidazolinium chloride (DMC), and related reagents, which can direct convert an oligosaccharide with a 2-acetamido sugar at the reducing terminus directly into the corresponding oxazoline in water. Therefore, oxazoline formation can now be achieved in water as the final step of any synthetic sequence, obviating the need for any further protecting group manipulations, and simplifying synthetic strategies. As an alternative to total synthesis, significant quantities of several structurally complicated N-glycans can be isolated from natural sources, such as egg yolks and soy bean flour. Enzymatic transformations of these materials, in concert with DMC-mediated oxazoline formation as a final step, allow access to a selection of N-glycan oxazoline structures both in larger quantities and in a more expedient fashion than is achievable by total synthesis.
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Affiliation(s)
- Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
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19
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Suthagar K, Jiao W, Munier-Lehmann H, Fairbanks AJ. Synthesis of sulfamide analogues of deoxthymidine monophosphate as potential inhibitors of mycobacterial cell wall biosynthesis. Carbohydr Res 2018; 457:32-40. [PMID: 29348046 DOI: 10.1016/j.carres.2018.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/08/2018] [Accepted: 01/08/2018] [Indexed: 11/26/2022]
Abstract
The recently discovered enzyme Mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt), which catalyses the phosphorylation of deoxythymidine monophosphate (dTMP) to give deoxythymidine diphosphate (dTDP), is indispensable for the growth and survival of M. tuberculosis as it plays an essential role in DNA synthesis. Inhibition of TMPKmt is an attractive avenue for the development of novel anti-tuberculosis agents. Based on the premise that sulfamide may be a suitable isostere of phosphate, deoxythymidine analogues comprising various substituted sulfamides at C5' were modelled in silico into the active site of TMPKmt (PDB accession code: 1N5K) using induced-fit docking methods. A selection of modelled compounds was synthesized, and their activity as inhibitors of TMPKmt was evaluated. Three compounds showed competitive inhibition of TMPKmt in the micromolar range (10-50 μM). Compounds were tested in vitro for anti-mycobacterial activity against M. smegmatis: three compounds showed weak anti-mycobacterial activity (MIC 250 μg/mL).
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Affiliation(s)
- Kajitha Suthagar
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Wanting Jiao
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand; Ferrier Research Institute, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Hélène Munier-Lehmann
- Institut Pasteur, Unité de Chimie et Biocatalyse, 28 rue du Dr Roux, 75724, Paris Cedex 15, France; CNRS UMR3523, 28 rue du Dr Roux, France
| | - Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand; Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand.
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20
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Poonthiyil V, Lindhorst TK, Golovko VB, Fairbanks AJ. Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles. Beilstein J Org Chem 2018; 14:11-24. [PMID: 29379576 PMCID: PMC5769080 DOI: 10.3762/bjoc.14.2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 12/20/2017] [Indexed: 12/27/2022] Open
Abstract
Glycoscience, despite its myriad of challenges, promises to unravel the causes of, potential new detection methods for, and novel therapeutic strategies against, many disease states. In the last two decades, glyco-gold nanoparticles have emerged as one of several potential new tools for glycoscientists. Glyco-gold nanoparticles consist of the unique structural combination of a gold nanoparticle core and an outer-shell comprising multivalent presentation of carbohydrates. The combination of the distinctive physicochemical properties of the gold core and the biological function/activity of the carbohydrates makes glyco-gold nanoparticles a valuable tool in glycoscience. In this review we present recent advances made in the use of one type of click chemistry, namely the azide-alkyne Huisgen cycloaddition, for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles.
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Affiliation(s)
- Vivek Poonthiyil
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, Kiel, 24098, Germany
| | - Thisbe K Lindhorst
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, Kiel, 24098, Germany
| | - Vladimir B Golovko
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, 6140, New Zealand
| | - Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
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21
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Kavianinia I, Yang SH, Kaur H, Harris PWR, Dobson RCJ, Fairbanks AJ, Brimble MA. Synthesis and incorporation of an advanced lipid peroxidation end-product building block into collagen mimetic peptides. Chem Commun (Camb) 2017; 53:8459-8462. [PMID: 28702630 DOI: 10.1039/c7cc05025a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Advanced lipid peroxidation end-products (ALEs) accumulate with ageing and oxidative stress-related diseases. Despite their potential therapeutic value, there are no suitably protected ALE building blocks reported in the literature to enable their site-specific incorporation into synthetic peptides. The synthesis of an Fmoc-protected ALE building block, N∈-(3-methylpyridinium)lysine (MP-lysine) and its incorporation into collagen model peptides is reported.
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Affiliation(s)
- Iman Kavianinia
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland, New Zealand
| | - Sung-Hyun Yang
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Harveen Kaur
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Paul W R Harris
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland, New Zealand
| | - Renwick C J Dobson
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland, New Zealand and Biomolecular Interaction Centre and School of Biological Sciences University of Canterbury, Private Bag 4800, Christchurch, New Zealand and Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony J Fairbanks
- Biomolecular Interaction Centre and Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Margaret A Brimble
- School of Biological Sciences, The University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds St, Auckland, New Zealand and School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland 1010, New Zealand.
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22
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Abstract
High yielding selective acetylation of only the anomeric hydroxyl of unprotected sugars is possible in aqueous solution using 2-chloro-1,3-dimethylimidazolinium chloride (DMC), thioacetic acid, and a suitable base. The reaction, which may be performed on a multi-gram scale, is stereoselective for sugars that possess a hydroxyl group at position-2, exclusively yielding the 1,2-trans products. The use of an iterative reagent addition procedure allows the use of sodium carbonate as the base, avoiding the formation of triethylammonium salts, which may hamper product purification. The glycosyl acetate products may be used as donor substrates for glycosidase-catalysed synthesis. The crude aqueous acetylation reaction mixture may also be used for this purpose.
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Affiliation(s)
- David Lim
- Department of Chemistry , University of Canterbury , Private Bag 4800 , Christchurch , 8140 , New Zealand .
| | - Antony J Fairbanks
- Department of Chemistry , University of Canterbury , Private Bag 4800 , Christchurch , 8140 , New Zealand .
- Biomolecular Interaction Centre , University of Canterbury , Private Bag 4800 , Christchurch , 8140 , New Zealand
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23
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North RA, Watson AJA, Pearce FG, Muscroft-Taylor AC, Friemann R, Fairbanks AJ, Dobson RCJ. Structure and inhibition of N-acetylneuraminate lyase from methicillin-resistant Staphylococcus aureus. FEBS Lett 2016; 590:4414-4428. [PMID: 27943302 DOI: 10.1002/1873-3468.12462] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/04/2016] [Accepted: 10/09/2016] [Indexed: 01/07/2023]
Abstract
N-Acetylneuraminate lyase is the first committed enzyme in the degradation of sialic acid by bacterial pathogens. In this study, we analyzed the kinetic parameters of N-acetylneuraminate lyase from methicillin-resistant Staphylococcus aureus (MRSA). We determined that the enzyme has a relatively high KM of 3.2 mm, suggesting that flux through the catabolic pathway is likely to be controlled by this enzyme. Our data indicate that sialic acid alditol, a known inhibitor of N-acetylneuraminate lyase enzymes, is a stronger inhibitor of MRSA N-acetylneuraminate lyase than of Clostridium perfringens N-acetylneuraminate lyase. Our analysis of the crystal structure of ligand-free and 2R-sialic acid alditol-bound MRSA N-acetylneuraminate lyase suggests that subtle dynamic differences in solution and/or altered binding interactions within the active site may account for species-specific inhibition.
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Affiliation(s)
- Rachel A North
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Andrew J A Watson
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand
| | - F Grant Pearce
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Andrew C Muscroft-Taylor
- Protein Science and Engineering, Callaghan Innovation, University of Canterbury, Christchurch, New Zealand
| | - Rosmarie Friemann
- Department of Chemistry and Molecular Biology, University of Gothenburg, Sweden.,Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Sweden.,Department of Structural Biology, School of Medicine, Stanford University, CA, USA
| | - Antony J Fairbanks
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.,Department of Chemistry, University of Canterbury, Christchurch, New Zealand
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Australia
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24
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Priyanka P, Fairbanks AJ. Synthesis of a hybrid type N-glycan heptasaccharide oxazoline for Endo M catalysed glycosylation. Carbohydr Res 2016; 426:40-5. [PMID: 27058295 DOI: 10.1016/j.carres.2016.03.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/18/2016] [Accepted: 03/18/2016] [Indexed: 01/15/2023]
Abstract
Endo-β-N-acetylglucosaminidases (ENGases) are versatile biocatalysts that allow access to a wide variety of defined homogenous N-linked glycoconjugates in a convergent manner. A hybrid-type N-glycan was accessed by total synthesis, converted to an oxazoline, and used as a donor substrate with both wild type Endo M and an N175Q glycosynthase Endo M mutant allowing the convergent synthesis of a glycosylated amino acid bearing a hybrid N-glycan structure.
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Affiliation(s)
- Pragya Priyanka
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Antony J Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
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25
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Priyanka P, Parsons TB, Miller A, Platt FM, Fairbanks AJ. Chemoenzymatic Synthesis of a Phosphorylated Glycoprotein. Angew Chem Int Ed Engl 2016; 55:5058-61. [DOI: 10.1002/anie.201600817] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Pragya Priyanka
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
| | - Thomas B. Parsons
- Department of Chemistry; Chemistry Research Laboratory; University of Oxford; Mansfield Road Oxford OX1 3TA UK
| | - Antonia Miller
- Callaghan Innovation; School of Biological Sciences; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
| | - Frances M. Platt
- Department of Pharmacology; University of Oxford; Mansfield Road Oxford OX1 3QT UK
| | - Antony J. Fairbanks
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
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26
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Affiliation(s)
- Pragya Priyanka
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
| | - Thomas B. Parsons
- Department of Chemistry; Chemistry Research Laboratory; University of Oxford; Mansfield Road Oxford OX1 3TA UK
| | - Antonia Miller
- Callaghan Innovation; School of Biological Sciences; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
| | - Frances M. Platt
- Department of Pharmacology; University of Oxford; Mansfield Road Oxford OX1 3QT UK
| | - Antony J. Fairbanks
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
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27
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Watson AJA, Alexander SR, Cox DJ, Fairbanks AJ. Protecting Group Dependence of Stereochemical Outcome of Glycosylation of 2-O-(Thiophen-2-yl)methyl Ether Protected Glycosyl Donors. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Poonthiyil V, Golovko VB, Fairbanks AJ. Size-optimized galactose-capped gold nanoparticles for the colorimetric detection of heat-labile enterotoxin at nanomolar concentrations. Org Biomol Chem 2016; 13:5215-23. [PMID: 25853438 DOI: 10.1039/c5ob00447k] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of a galactose-capped gold nanoparticle-based colorimetric sensor for the detection of the lectin heat-labile enterotoxin is reported. Heat-labile enterotoxin is one of the pathogenic agents responsible for the intestinal disease called 'traveller's diarrhoea'. By means of specific interaction between galactose moieties attached to the surface of gold nanoparticles and receptors on the B-subunit of heat-labile enterotoxin (LTB), the gold nanoparticles reported here act as an efficient colorimetric sensor, which can detect the toxin at nanomolar concentrations. The effect of gold nanoparticle size on the detection sensitivity was investigated in detail. Amongst the various sizes of gold nanoparticles studied (2, 7, 12, and 20 nm), the 12 nm sized gold nanoparticles were found to be the most efficient, with a minimum heat-labile enterotoxin detection concentration of 100 nM. The red to purple colour change of the gold nanoparticle solution occurred within two minutes, indicating rapid toxin sensing.
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Affiliation(s)
- Vivek Poonthiyil
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand.
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29
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Abstract
A series ofarabino N-glycosyl sulfamides, forced to adopt the furanose form by removal of the 5-hydroxyl group, were synthesised as putative isosteric mimics of decaprenolphosphoarabinose, the donor processed by arabinosyltransferases during mycobacterial cell wall assembly.
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Affiliation(s)
- Kajitha Suthagar
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
| | - Antony J. Fairbanks
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
- Biomolecular Interaction Centre
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30
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Alexander SR, Fairbanks AJ. Direct aqueous synthesis of cyanomethyl thioglycosides from reducing sugars; ready access to reagents for protein glycosylation. Org Biomol Chem 2016; 14:6679-82. [DOI: 10.1039/c6ob01069e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unprotected carbohydrates can be directly converted into cyanooethyl thioglycosides, which in turn may be used for protein glycosylation, in a completely stereoselective manner by reaction with 2-chloro-1,3-dimethylimidazolinium chloride (DMC) and mercaptoacetonitrile in aqueous solution.
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Affiliation(s)
| | - Antony J. Fairbanks
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
- Biomolecular Interaction Centre
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31
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Poonthiyil V, Nagesh PT, Husain M, Golovko VB, Fairbanks AJ. Gold Nanoparticles Decorated with Sialic Acid Terminated Bi-antennary N-Glycans for the Detection of Influenza Virus at Nanomolar Concentrations. ChemistryOpen 2015; 4:662. [PMID: 27308188 PMCID: PMC4906511 DOI: 10.1002/open.201500182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Invited for this month's cover picture is the group of Professor Antony Fairbanks and his collaborators at the University of Canterbury and University of Otago. The cover shows the isolation of complex bi-antennary oligosaccharides from hens' eggs and their conjugation to gold nanoparticles. Gold nanoparticles carrying these sugars can then bind to specific receptors (hemagglutinin) on the surface of the influenza virus, causing particle aggregation, which changes their spectroscopic properties. Upon aggregation, they undergo a red-shift in their surface plasmon resonance, as illustrated by the bound particles shining in the cover image. These changes in spectroscopic properties are the basis of a detection system capable of detecting viral hemagglutinin at nanomolar concentrations, as well as the virus itself. For more details, see the Full Paper on p. 708 ff.Read the full text of the article at 10.1002/open.201500109.
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Affiliation(s)
- Vivek Poonthiyil
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- The MacDiarmid Institute for Advanced Materials and NanotechnologyWellington6140New Zealand
| | - Prashanth T. Nagesh
- Department of Microbiology and ImmunologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| | - Matloob Husain
- Department of Microbiology and ImmunologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| | - Vladimir B. Golovko
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- The MacDiarmid Institute for Advanced Materials and NanotechnologyWellington6140New Zealand
| | - Antony J. Fairbanks
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- Biomolecular Interaction CentreUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
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32
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Poonthiyil V, Nagesh PT, Husain M, Golovko VB, Fairbanks AJ. Gold Nanoparticles Decorated with Sialic Acid Terminated Bi-antennary N-Glycans for the Detection of Influenza Virus at Nanomolar Concentrations. ChemistryOpen 2015; 4:708-16. [PMID: 27308196 PMCID: PMC4906500 DOI: 10.1002/open.201500109] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Indexed: 01/18/2023] Open
Abstract
Gold nanoparticles decorated with full-length sialic acid terminated complex bi-antennary N-glycans, synthesized with glycans isolated from egg yolk, were used as a sensor for the detection of both recombinant hemagglutinin (HA) and whole influenza A virus particles of the H1N1 subtype. Nanoparticle aggregation was induced by interaction between the sialic acid termini of the glycans attached to gold and the multivalent sialic acid binding sites of HA. Both dynamic light scattering (DLS) and UV/Vis spectroscopy demonstrated the efficiency of the sensor, which could detect viral HA at nanomolar concentrations and revealed a linear relationship between the extent of nanoparticle aggregation and the concentration of HA. UV/Vis studies also showed that these nanoparticles can selectively detect an influenza A virus strain that preferentially binds sialic acid terminated glycans with α(2→6) linkages over a strain that prefers glycans with terminal α(2→3)-linked sialic acids.
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Affiliation(s)
- Vivek Poonthiyil
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- The MacDiarmid Institute for Advanced Materials and NanotechnologyWellington6140New Zealand
| | - Prashanth T. Nagesh
- Department of Microbiology and ImmunologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| | - Matloob Husain
- Department of Microbiology and ImmunologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| | - Vladimir B. Golovko
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- The MacDiarmid Institute for Advanced Materials and NanotechnologyWellington6140New Zealand
| | - Antony J. Fairbanks
- Department of ChemistryUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
- Biomolecular Interaction CentreUniversity of CanterburyPrivate Bag 4800Christchurch8140New Zealand
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33
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Abstract
Creative with carbohydrates! This Virtual Issue on Carbohydrates in the 21stCentury: Synthesis and Applications highlights current research in the carbohydrate field in which synthesis underpins the development of novel applications of sugar‐based materials in medicine, diagnostics, and as antiinfectives.![]()
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Affiliation(s)
- Antony J Fairbanks
- Department of Chemistry University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
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34
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Poonthiyil V, Nagesh PT, Husain M, Golovko VB, Fairbanks AJ. Cover Picture: Gold Nanoparticles Decorated with Sialic Acid Terminated Bi-antennary N-Glycans for the Detection of Influenza Virus at Nanomolar Concentrations (ChemistryOpen 6/2015). Chemistry 2015. [PMCID: PMC4906496 DOI: 10.1002/open.201500183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Vivek Poonthiyil
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology; Wellington 6140 New Zealand
| | - Prashanth T. Nagesh
- Department of Microbiology and Immunology; University of Otago; PO Box 56 Dunedin 9054 New Zealand
| | - Matloob Husain
- Department of Microbiology and Immunology; University of Otago; PO Box 56 Dunedin 9054 New Zealand
| | - Vladimir B. Golovko
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology; Wellington 6140 New Zealand
| | - Antony J. Fairbanks
- Department of Chemistry; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
- Biomolecular Interaction Centre; University of Canterbury; Private Bag 4800 Christchurch 8140 New Zealand
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35
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Suthagar K, Watson AJ, Wilkinson BL, Fairbanks AJ. Synthesis of arabinose glycosyl sulfamides as potential inhibitors of mycobacterial cell wall biosynthesis. Eur J Med Chem 2015; 102:153-66. [DOI: 10.1016/j.ejmech.2015.07.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/17/2015] [Accepted: 07/30/2015] [Indexed: 10/23/2022]
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36
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Singh GP, Watson AJA, Fairbanks AJ. Achiral 2-Hydroxy Protecting Group for the Stereocontrolled Synthesis of 1,2-cis-α-Glycosides by Six-Ring Neighboring Group Participation. Org Lett 2015; 17:4376-9. [PMID: 26308903 DOI: 10.1021/acs.orglett.5b02226] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycosylation of a fully armed donor bearing a 2-O-(trimethoxybenzenethiol) ethyl ether protecting group is completely α-selective with a range of carbohydrate alcohol acceptors. Low-temperature NMR studies confirm the intermediacy of cyclic sulfonium ion intermediates arising from six-membered β-sulfonium ring neighboring group participation. Selective protecting group removal is achieved in high yield in a single operation by S-methylation and base-induced β-elimination.
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Affiliation(s)
- Govind P Singh
- Department of Chemistry and ‡Biomolecular Interaction Centre, University of Canterbury , Private Bag 4800, Christchurch 8140, New Zealand
| | - Andrew J A Watson
- Department of Chemistry and ‡Biomolecular Interaction Centre, University of Canterbury , Private Bag 4800, Christchurch 8140, New Zealand
| | - Antony J Fairbanks
- Department of Chemistry and ‡Biomolecular Interaction Centre, University of Canterbury , Private Bag 4800, Christchurch 8140, New Zealand
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37
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McIntosh JD, Brimble MA, Brooks AES, Dunbar PR, Kowalczyk R, Tomabechi Y, Fairbanks AJ. Convergent chemo-enzymatic synthesis of mannosylated glycopeptides; targeting of putative vaccine candidates to antigen presenting cells. Chem Sci 2015; 6:4636-4642. [PMID: 28717478 PMCID: PMC5500846 DOI: 10.1039/c5sc00952a] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/11/2015] [Indexed: 01/11/2023] Open
Abstract
The combination of solid phase peptide synthesis and endo-β-N-acetylglucosaminidase (ENGase) catalysed glycosylation is a powerful convergent synthetic method allowing access to glycopeptides bearing full-length N-glycan structures. Mannose-terminated N-glycan oligosaccharides, produced by either total or semi-synthesis, were converted into oxazoline donor substrates. A peptide from the human cytomegalovirus (CMV) tegument protein pp65 that incorporates a well-characterised T cell epitope, containing N-acetylglucosamine at specific Asn residues, was accessed by solid phase peptide synthesis, and used as an acceptor substrate. High-yielding enzymatic glycosylation afforded glycopeptides bearing defined homogeneous high-mannose N-glycan structures. These high-mannose containing glycopeptides were tested for enhanced targeting to human antigen presenting cells (APCs), putatively mediated via the mannose receptor, and for processing by the APCs for presentation to human CD8+ T cells specific for a 9-mer epitope within the peptide. Binding assays showed increased binding of glycopeptides to APCs compared to the non-glycosylated control. Glycopeptides bearing high-mannose N-glycan structures at a single site outside the T cell epitope were processed and presented by the APCs to allow activation of a T cell clone. However, the addition of a second glycan within the T cell epitope resulted in ablation of T cell activation. We conclude that chemo-enzymatic synthesis of mannosylated glycopeptides enhances uptake by human APCs while preserving the immunogenicity of peptide epitopes within the glycopeptides, provided those epitopes are not themselves glycosylated.
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Affiliation(s)
- Julie D McIntosh
- School of Biological Sciences , University of Auckland , Private Bag 92019 , Auckland 1142 , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences , The University of Auckland , 23 Symonds St , Auckland , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - Anna E S Brooks
- School of Biological Sciences , University of Auckland , Private Bag 92019 , Auckland 1142 , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - P Rod Dunbar
- School of Biological Sciences , University of Auckland , Private Bag 92019 , Auckland 1142 , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - Renata Kowalczyk
- School of Chemical Sciences , The University of Auckland , 23 Symonds St , Auckland , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - Yusuke Tomabechi
- Department of Chemistry , University of Canterbury , Private Bag 4800 , Christchurch , 8140 , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
| | - Antony J Fairbanks
- Department of Chemistry , University of Canterbury , Private Bag 4800 , Christchurch , 8140 , New Zealand .
- Maurice Wilkins Centre for Molecular Biodiscovery , University of Auckland , Private Bag 92019 , Auckland 1010 , New Zealand
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Newton AE, Fairbanks AJ, Golding M, Andrewes P, Gerrard JA. The influence of emulsion structure on the Maillard reaction of ghee. Food Chem 2015; 173:1243-9. [DOI: 10.1016/j.foodchem.2014.10.147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/03/2014] [Accepted: 10/28/2014] [Indexed: 10/24/2022]
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Somasundaram B, Fee CJ, Fredericks R, Watson AJA, Fairbanks AJ, Hall RJ. A surface plasmon resonance assay for measurement of neuraminidase inhibition, sensitivity of wild-type influenza neuraminidase and its H274Y mutant to the antiviral drugs zanamivir and oseltamivir. J Mol Recognit 2015; 28:521-7. [PMID: 25727669 DOI: 10.1002/jmr.2467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/18/2014] [Accepted: 01/10/2015] [Indexed: 11/09/2022]
Abstract
Antiviral resistance is currently monitored by a labelled enzymatic assay, which can give inconsistent results because of the short half-life of the labelled product, and variations in assay conditions. In this paper, we describe a competitive surface plasmon resonance (SPR) inhibition assay for measuring the sensitivities of wild-type neuraminidase (WT NA) and the H274Y (histidine 274 tyrosine) NA mutant to antiviral drugs. The two NA isoforms were expressed in High-five™ (Trichoplusia ni) insect cells. A spacer molecule (1,6-hexanediamine (HDA)) was conjugated to the 7-hydroxyl group of zanamivir, and the construct (HDA-zanamivir) was immobilized onto a SPR sensor chip to obtain a final immobilization response of 431 response units. The immobilized HDA-zanamivir comprised a bio-specific ligand for the WT and mutant proteins. The effects of the natural substrate (sialic acid) and two inhibitors (zanamivir and oseltamivir) on NA binding to the immobilized ligand were studied. The processed SPR data was analysed to determine 50% inhibitory concentrations (IC50-spr ), using a log dose-response curve fit. Although both NA isoforms had almost identical IC50-spr values for sialic acid (WT = 5.5 nM; H274Y mutant = 3.25 nM) and zanamivir (WT = 2.16 nM; H274Y mutant = 2.42 nM), there were significant differences between the IC50-spr values obtained for the WT (7.7 nM) and H274Y mutant (256 nM) NA in the presence of oseltamivir, indicating that oseltamivir has a reduced affinity for the H274Y mutant. The SPR inhibition assay strategy presented in this work could be applied for the rapid screening of newly emerging variants of NA for their sensitivity to antiviral drugs.
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Affiliation(s)
- Balaji Somasundaram
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Chemical and Process Engineering, University of Canterbury, Private Bag 4800, 8140, Christchurch, Canterbury, New Zealand
| | - Conan J Fee
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Chemical and Process Engineering, University of Canterbury, Private Bag 4800, 8140, Christchurch, Canterbury, New Zealand
| | - Rayleen Fredericks
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Chemical and Process Engineering, University of Canterbury, Private Bag 4800, 8140, Christchurch, Canterbury, New Zealand
| | - Andrew J A Watson
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Department of Chemistry, University of Canterbury, Private Bag 4800, 8140, Christchurch, New Zealand
| | - Antony J Fairbanks
- Biomolecular Interaction Centre, University of Canterbury, Christchurch, New Zealand.,Department of Chemistry, University of Canterbury, Private Bag 4800, 8140, Christchurch, New Zealand
| | - Richard J Hall
- National Centre for Biosecurity and Infectious Disease (NCBID), Institute of Environmental Science and Research (ESR), 66 Ward Street, 5018, Upper Hutt, New Zealand
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Somasundaram B, Fee CJ, Fredericks R, Watson AJA, Fairbanks AJ. Development of a surface plasmon resonance assay to measure the binding affinity of wild-type influenza neuraminidase and its H274Y mutant to the antiviral drug zanamivir. J Mol Recognit 2015; 28:87-95. [PMID: 25599664 DOI: 10.1002/jmr.2417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/02/2014] [Accepted: 08/10/2014] [Indexed: 11/09/2022]
Abstract
Influenza is one of the most common infections of the upper respiratory tract. Antiviral drugs that are currently used to treat influenza, such as oseltamivir and zanamivir, are neuraminidase (NA) inhibitors. However, the virus may develop resistance through single-point mutations of NA. Antiviral resistance is currently monitored by a labelled enzymatic assay, which can be inconsistent because of the short half-life of the labelled product and variations in the assay conditions. In this paper, we describe a label-free surface plasmon resonance (SPR) assay for measuring the binding affinity of NA-drug interactions. Wild-type (WT) NA and a histidine 274 tyrosine (H274Y) mutant were expressed in High Five™ (Trichoplusia ni) insect cells. A spacer molecule (1,6-hexanediamine) was site-specifically conjugated to the 7-hydroxyl group of zanamivir, which is not involved in binding to NA, and the construct was immobilized onto a SPR sensor Chip to obtain a final immobilization response of 431 response units. Binding responses obtained for WT and H274Y mutant NAs were fitted to a simple Langmuir 1:1 model with drift to obtain the association (ka ) and dissociation (kd ) rate constants. The ratio between the binding affinities for the two isoforms was comparable to literature values obtained using labelled enzyme assays. Significant potential exists for an extension of this approach to test for drug resistance of further NA mutants against zanamivir and other antiviral drugs, perhaps paving the way for a reliable SPR biosensor assay that may replace labelled enzymatic assays.
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Affiliation(s)
- Balaji Somasundaram
- Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, New Zealand, 8140; Department of Chemical and Process Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand, 8140
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41
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Lepe PGT, Tucker N, Simmons L, Watson AJA, Fairbanks AJ, Staiger MP. Sub-micron sized saccharide fibres via electrospinning. ACTA ACUST UNITED AC 2015. [DOI: 10.1515/esp-2016-0001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractIn this work, the production of continuous submicron diameter saccharide fibres is shown to be possible using the electrospinning process. The mechanism for the formation of electrospun polymer fibres is usually attributed to the physical entanglement of long molecular chains. The ability to electrospin continuous fibre from a low molecular weight saccharides was an unexpected phenomenon. The formation of sub-micron diameter “sugar syrup” fibres was observed in situ using highspeed video. The trajectory of the electrospun saccharide fibre was observed to follow that typical of electrospun polymers. Based on initial food grade glucose syrup tests, various solutions based on combinations of syrup components, i.e. mono-, di- and tri-saccharides, were investigated to map out materials and electrospinning conditions thatwould lead to the formation of fibre. Thiswork demonstrated that sucrose exhibits the highest propensity for fibre formation during electrospinning amongst the various types of saccharide solutions studied. The possibility of electrospinning low molecular weight saccharides into sub-micron fibres has implications for the electrospinability of supramolecular polymers and other biomaterials.
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Poonthiyil V, Golovko VB, Fairbanks AJ. Control of Gold Nanostructure Morphology by Variation of Temperature and Reagent Ratios in the Turkevich Reaction. Aust J Chem 2015. [DOI: 10.1071/ch14446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In this paper, we demonstrate that the Turkevich reaction can be used to obtain not only spherical gold nanoparticles of various sizes, but also nanoparticles of different morphologies. The effect of the molar ratios of citrate to HAuCl4 at various temperatures has been studied. It was found that the reagent ratio plays a significant role in defining the morphology of the gold nanosystems formed at low temperatures. This study shows that by controlling the reagent ratios and the reaction temperature of the Turkevich reaction, nano-structured gold systems with various shapes, including spheres, wires, networks, and systems comprising polygonal nanoparticles only or nanochains only, with the latter two morphologies reported for the first time, can be obtained. The gold nanosystems obtained in this fashion were characterised by transmission electron microscopy and UV–visible absorption spectroscopy.
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Suthagar K, Polson MIJ, Fairbanks AJ. Unexpected furanose/pyranose equilibration of N-glycosyl sulfonamides, sulfamides and sulfamates. Org Biomol Chem 2015; 13:6573-9. [DOI: 10.1039/c5ob00851d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Arabino N-glycosyl sulfamides, sulfonamides and sulfamates convert from the furanose to the thermodynamically preferred pyranose form in aqueous solution.
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Affiliation(s)
- Kajitha Suthagar
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
| | | | - Antony J. Fairbanks
- Department of Chemistry
- University of Canterbury
- Christchurch 8140
- New Zealand
- Biomolecular Interaction Centre
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Kowalczyk R, Brimble MA, Tomabechi Y, Fairbanks AJ, Fletcher M, Hay DL. Convergent chemoenzymatic synthesis of a library of glycosylated analogues of pramlintide: structure-activity relationships for amylin receptor agonism. Org Biomol Chem 2014; 12:8142-51. [PMID: 25030939 DOI: 10.1039/c4ob01208a] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Pramlintide (Symlin®), a synthetic analogue of the naturally occurring pancreatic hormone amylin, is currently used with insulin in adjunctive therapy for type 1 and type 2 diabetes mellitus. Herein we report a systematic study into the effect that N-glycosylation of pramlintide has on activation of amylin receptors. A highly efficient convergent synthetic route, involving a combination of solid phase peptide synthesis and enzymatic glycosylation, delivered a library of N-glycosylated variants of pramlintide bearing either GlcNAc, the core N-glycan pentasaccharide [Man3(GlcNAc)2] or a complex biantennary glycan [(NeuAcGalGlcNAcMan)2Man(GlcNAc)2] at each of its six asparagine residues. The majority of glycosylated versions of pramlintide were potent receptor agonists, suggesting that N-glycosylation may be used as a tool to optimise the pharmacokinetic properties of pramlintide and so deliver improved therapeutic agents for the treatment of diabetes and obesity.
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Affiliation(s)
- Renata Kowalczyk
- The School of Chemical Sciences, University of Auckland, 23 Symonds St, Auckland 1010, New Zealand.
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45
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North RA, Kessans SA, Griffin MDW, Watson AJA, Fairbanks AJ, Dobson RCJ. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of N-acetylmannosamine-6-phosphate 2-epimerase from methicillin-resistant Staphylococcus aureus. Acta Crystallogr F Struct Biol Commun 2014; 70:650-5. [PMID: 24817730 PMCID: PMC4014339 DOI: 10.1107/s2053230x14007171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/31/2014] [Indexed: 12/12/2022] Open
Abstract
Sialic acids are one of the most important carbohydrate classes in biology. Some bacterial pathogens can scavenge sialic acids from their surrounding environment and degrade them as a source of carbon, nitrogen and energy. This sequestration and subsequent catabolism of sialic acid require a cluster of genes known as the `Nan-Nag' cluster. The enzymes coded by these genes are important for pathogen colonization and persistence. Importantly, the Nan-Nag genes have proven to be essential for Staphylococcus aureus growth on sialic acids, suggesting that the pathway is a viable antibiotic drug target. The enzyme N-acetylmannosamine-6-phosphate 2-epimerase is involved in the catabolism of sialic acid; specifically, the enzyme converts N-acetylmannosamine-6-phosphate into N-acetylglucosamine-6-phosphate. The gene was cloned into an appropriate expression vector, and recombinant protein was expressed in Escherichia coli BL21 (DE3) cells and purified via a three-step procedure. Purified N-acetylmannosamine-6-phosphate 2-epimerase was screened for crystallization. The best crystal diffracted to a resolution of beyond 1.84 Å in space group P21212. Understanding the structural nature of this enzyme from methicillin-resistant S. aureus will provide us with the insights necessary for the development of future antibiotics.
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Affiliation(s)
- Rachel A. North
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Sarah A. Kessans
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Michael D. W. Griffin
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Andrew J. A. Watson
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Antony J. Fairbanks
- Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Renwick C. J. Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
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Tomabechi Y, Squire MA, Fairbanks AJ. Endo-β-N-Acetylglucosaminidase catalysed glycosylation: tolerance of enzymes to structural variation of the glycosyl amino acid acceptor. Org Biomol Chem 2014; 12:942-55. [DOI: 10.1039/c3ob42104j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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47
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Tomabechi Y, Krippner G, Rendle PM, Squire MA, Fairbanks AJ. Glycosylation of Pramlintide: Synthetic Glycopeptides that Display In Vitro and In Vivo Activities as Amylin Receptor Agonists. Chemistry 2013; 19:15084-8. [DOI: 10.1002/chem.201303303] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 12/16/2022]
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Newton AE, Fairbanks AJ, Golding M, Andrewes P, Gerrard JA. The role of the Maillard reaction in the formation of flavour compounds in dairy products--not only a deleterious reaction but also a rich source of flavour compounds. Food Funct 2013; 3:1231-41. [PMID: 22948260 DOI: 10.1039/c2fo30089c] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dairy products are heated both during processing and by consumers during food preparation; consumers place a high level of importance on flavour when assessing product acceptability. Of particular importance to the flavour of heated dairy products is the highly complex network of Maillard reactions. Much focus has been placed on the undesirable flavours generated through the Maillard reaction and how to minimise the formation of these flavours. However, beneficial flavours can also be formed by the Maillard reaction; dairy products, such as ghee, are formed by heating and are characterised by the unique flavour generated by this chemistry. This review looks at the Maillard reaction as a source of beneficial flavours for cooked dairy products and the application of models to the study of flavour formation in food systems. Models are typically used to study complex reactions in a simplified way; however, they are not always applicable to food systems.
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Affiliation(s)
- Angela E Newton
- Biomolecular Interaction Centre, University of Canterbury, PB 4800, Christchurch, 8140, New Zealand
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49
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North RA, Kessans SA, Atkinson SC, Suzuki H, Watson AJA, Burgess BR, Angley LM, Hudson AO, Varsani A, Griffin MDW, Fairbanks AJ, Dobson RCJ. Cloning, expression, purification, crystallization and preliminary X-ray diffraction studies of N-acetylneuraminate lyase from methicillin-resistant Staphylococcus aureus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:306-12. [PMID: 23519810 PMCID: PMC3606580 DOI: 10.1107/s1744309113003060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 01/30/2013] [Indexed: 01/13/2023]
Abstract
The enzyme N-acetylneuraminate lyase (EC 4.1.3.3) is involved in the metabolism of sialic acids. Specifically, the enzyme catalyzes the retro-aldol cleavage of N-acetylneuraminic acid to form N-acetyl-D-mannosamine and pyruvate. Sialic acids comprise a large family of nine-carbon amino sugars, all of which are derived from the parent compound N-acetylneuraminic acid. In recent years, N-acetylneuraminate lyase has received considerable attention from both mechanistic and structural viewpoints and has been recognized as a potential antimicrobial drug target. The N-acetylneuraminate lyase gene was cloned from methicillin-resistant Staphylococcus aureus genomic DNA, and recombinant protein was expressed and purified from Escherichia coli BL21 (DE3). The enzyme crystallized in a number of crystal forms, predominantly from PEG precipitants, with the best crystal diffracting to beyond 1.70 Å resolution in space group P2₁. Molecular replacement indicates the presence of eight monomers per asymmetric unit. Understanding the structural biology of N-acetylneuraminate lyase in pathogenic bacteria, such as methicillin-resistant S. aureus, will provide insights for the development of future antimicrobials.
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Affiliation(s)
- Rachel A. North
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Sarah A. Kessans
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Sarah C. Atkinson
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Victoria, Australia
| | - Hironori Suzuki
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
| | - Andrew J. A. Watson
- Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Benjamin R. Burgess
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Lauren M. Angley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - André O. Hudson
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, NY 14623, USA
| | - Arvind Varsani
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
- Electron Microscope Unit, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
| | - Michael D. W. Griffin
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
| | - Antony J. Fairbanks
- Department of Chemistry, University of Canterbury, Christchurch 8140, New Zealand
| | - Renwick C. J. Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8041, New Zealand
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia
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Barker MK, Wilkinson BL, Faridmoayer A, Scaman CH, Fairbanks AJ, Rose DR. Production and crystallization of processing α-glucosidase I: Pichia pastoris expression and a two-step purification toward structural determination. Protein Expr Purif 2011; 79:96-101. [PMID: 21640829 DOI: 10.1016/j.pep.2011.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/19/2011] [Accepted: 05/20/2011] [Indexed: 12/17/2022]
Abstract
Eukaryotic N-glycoprotein processing in the endoplasmic reticulum begins with the catalytic action of processing α-glucosidase I (αGlu). αGlu trims the terminal glucose from nascent glycoproteins in an inverting-mechanism glycoside hydrolysis reaction. αGlu has been studied in terms of kinetic parameters and potential key residues; however, the active site is unknown. A structural model would yield important insights into the reaction mechanism. A model would also be useful in developing specific therapeutics, as αGlu is a viable drug target against viruses with glycosylated envelope proteins. However, due to lack of a high-yielding overexpression and purification scheme, no eukaryotic structural model of αGlu has been determined. To address this issue, we overexpressed the Saccharomyces cerevisiae soluble αGlu, Cwht1p, in the host Pichia pastoris. It was purified in a simple two-step protocol, with a final yield of 4.2mg Cwht1p per liter of growth culture. To test catalytic activity, we developed a modified synthesis of a tetrasaccharide substrate, Glc(3)ManOMe. Cwht1p with Glc(3)ManOMe shows a K(m) of 1.26 mM. Cwht1p crystals were grown and subjected to X-ray irradiation, giving a complete diffraction dataset to 2.04 Å resolution. Work is ongoing to obtain phases so that we may further understand this fundamental member of the N-glycosylation pathway through the discovery of its molecular structure.
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Affiliation(s)
- Megan K Barker
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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