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Hsieh YC, Guan HH, Lin CC, Huang TY, Chuankhayan P, Chen NC, Wang NH, Hu PL, Tsai YC, Huang YC, Yoshimura M, Lin PJ, Hsieh YH, Chen CJ. Structure-Based High-Efficiency Homogeneous Antibody Platform by Endoglycosidase Sz Provides Insights into Its Transglycosylation Mechanism. JACS AU 2024; 4:2130-2150. [PMID: 38938812 PMCID: PMC11200250 DOI: 10.1021/jacsau.4c00004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 06/29/2024]
Abstract
Monoclonal antibodies (mAbs) have gradually dominated the drug markets for various diseases. Improvement of the therapeutic activities of mAbs has become a critical issue in the pharmaceutical industry. A novel endo-β-N-acetylglucosaminidase, EndoSz, from Streptococcus equisubsp. zooepidemicus Sz105 is discovered and applied to enhance the activities of mAbs. Our studies demonstrate that the mutant EndoSz-D234M possesses an excellent transglycosylation activity to generate diverse glycoconjugates on mAbs. We prove that EndoSz-D234M can be applied to various marketed therapeutic antibodies and those in development for antibody remodeling. The remodeled homogeneous antibodies (mAb-G2S2) produced by EndoSz-D234M increase the relative ADCC activities by 3-26-fold. We further report the high-resolution crystal structures of EndoSz-D234M in the apo-form at 2.15 Å and the complex form with a bound G2S2-oxazoline intermediate at 2.25 Å. A novel pH-jump method was utilized to obtain the complex structure with a high resolution. The detailed interactions of EndoSz-D234M and the carried G2S2-oxazoline are hence delineated. The oxazoline sits in a hole, named the oxa-hole, which stabilizes the G2S2-oxazoline in transit and catalyzes the further transglycosylation reaction while targeting Asn-GlcNAc (+1) of Fc. In the oxa-hole, the H-bonding network involved with oxazoline dominates the transglycosylation activity. A mobile loop2 (a.a. 152-159) of EndoSz-D234M reshapes the binding grooves for the accommodation of G2S2-oxazoline upon binding, at which Trp154 forms a hydrogen bond with Man (-2). The long loop4 (a.a. 236-248) followed by helix3 is capable of dominating the substrate selectivity of EndoSz-D234M. In addition, the stepwise transglycosylation behavior of EndoSz-D234M is elucidated. Based on the high-resolution structures of the apo-form and the bound form with G2S2-oxazoline as well as a systematic mutagenesis study of the relative transglycosylation activity, the transglycosylation mechanism of EndoSz-D234M is revealed.
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Affiliation(s)
- Yin-Cheng Hsieh
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Hong-Hsiang Guan
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Chien-Chih Lin
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Teng-Yi Huang
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Phimonphan Chuankhayan
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Nai-Chi Chen
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Nan-Hsuan Wang
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Pu-Ling Hu
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Yi-Chien Tsai
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Yen-Chieh Huang
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Masato Yoshimura
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Pei-Ju Lin
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
| | - Yih-Huang Hsieh
- OBI
Pharma, Inc., No. 508, Sec. 7, ZhongXiao E. Rd, Nangang Dist., Taipei City 115, Taiwan
| | - Chun-Jung Chen
- Life
Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Hsinchu 300092, Taiwan
- Institute
of Biotechnology and industry Science, and University Center for Bioscience
and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department
of Physics, National Tsing Hua University, Hsinchu 300044, Taiwan
- Department
of Biological Science and Technology, National
Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
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2
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Katoh T, Yamamoto K. Innovative Preparation of Biopharmaceuticals Using Transglycosylation Activity of Microbial Endoglycosidases. J Appl Glycosci (1999) 2021; 68:1-9. [PMID: 34354540 PMCID: PMC8113915 DOI: 10.5458/jag.jag.jag-2020_0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/16/2020] [Indexed: 12/02/2022] Open
Abstract
Most functional biopharmaceuticals such as antibodies are glycoproteins carrying N-linked oligosaccharides (N-glycans). In animal cells, these glycans are generally expressed as heterogeneous glycoforms that are difficult to separate into a pure form. The structure of these glycans directly affects several biological aspects of the glycoproteins, especially binding affinity. Therefore, the preparation of glycoproteins with well-defined and homogeneous glycoforms is necessary for functional studies and improved efficacy, particularly for biopharmaceuticals. This review describes the recent remarkable progress in the development and production of biopharmaceutical glycan-modified antibodies, through the use of glycan remodeling using microbial endoglycosidases and sophisticated glycoengineering techniques utilizing microbial enzymatic reaction mechanisms.
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Affiliation(s)
| | - Kenji Yamamoto
- 2 Center for Innovative and Joint Research, Wakayama University
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3
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/20/2019] [Indexed: 12/16/2022]
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Abstract
Glycosylation is one of the most prevalent posttranslational modifications that profoundly affects the structure and functions of proteins in a wide variety of biological recognition events. However, the structural complexity and heterogeneity of glycoproteins, usually resulting from the variations of glycan components and/or the sites of glycosylation, often complicates detailed structure-function relationship studies and hampers the therapeutic applications of glycoproteins. To address these challenges, various chemical and biological strategies have been developed for producing glycan-defined homogeneous glycoproteins. This review highlights recent advances in the development of chemoenzymatic methods for synthesizing homogeneous glycoproteins, including the generation of various glycosynthases for synthetic purposes, endoglycosidase-catalyzed glycoprotein synthesis and glycan remodeling, and direct enzymatic glycosylation of polypeptides and proteins. The scope, limitation, and future directions of each method are discussed.
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Affiliation(s)
- Chao Li
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Lai-Xi Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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5
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Fairbanks AJ. The ENGases: versatile biocatalysts for the production of homogeneous N-linked glycopeptides and glycoproteins. Chem Soc Rev 2018; 46:5128-5146. [PMID: 28681051 DOI: 10.1039/c6cs00897f] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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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6
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Fairbanks AJ. Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines. Beilstein J Org Chem 2018; 14:416-429. [PMID: 29520306 PMCID: PMC5827820 DOI: 10.3762/bjoc.14.30] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/31/2018] [Indexed: 12/15/2022] Open
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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7
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Ishii N, Ogiwara K, Sano K, Kumada J, Yamamoto K, Matsuzaki Y, Matsuo I. Specificity of Donor Structures for endo-β-N-Acetylglucosaminidase-Catalyzed Transglycosylation Reactions. Chembiochem 2017; 19:136-141. [PMID: 29125207 DOI: 10.1002/cbic.201700506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Indexed: 11/11/2022]
Abstract
To demonstrate the structural specificity of the glycosyl donor for the transglycosylation reaction by using endo-β-N-acetylglucosaminidase from Mucor hiemalis (endo-M), a series of tetrasaccharide oxazoline derivatives was synthesized. These derivatives correspond to the core structure of an asparagine-linked glycoprotein glycan with a β-mannose unit of a non-natural-type monosaccharide, including β-glucose, β-galactose, and β-talose in place of the β-mannose moiety. The transglycosylation activity of wildtype (WT) endo-M and two mutants, N175Q and N175A, was examined by using these tetrasaccharide donors with p-nitrophenyl N-acetylglucosaminide (GlcNAc-pNp). The essential configuration of the hydroxy group for the transglycosylation reaction was determined. On the basis of these results, the transglycosylation reaction was investigated by using chemically modified donors, and transglycosylated products were successfully obtained.
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Affiliation(s)
- Nozomi Ishii
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kyryu Gunma, 376-8515, Japan
| | - Ken Ogiwara
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kyryu Gunma, 376-8515, Japan
| | - Kanae Sano
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kyryu Gunma, 376-8515, Japan
| | - Jyunichi Kumada
- Tokyo Chemical Industry Co., Ltd., 6-15-9 Toshima, Kita-ku, Tokyo, 114-0003, Japan
| | - Kenji Yamamoto
- Research Institute of Bioresources and Biotechnology, Ishikawa Prefectural University, 1-308 Suematsu, Nonoichi, Ishikawa, 921-8836, Japan
| | - Yuji Matsuzaki
- Tokyo Chemical Industry Co., Ltd., 6-15-9 Toshima, Kita-ku, Tokyo, 114-0003, Japan
| | - Ichiro Matsuo
- Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kyryu Gunma, 376-8515, Japan
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8
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Li C, Wang LX. Endoglycosidases for the Synthesis of Polysaccharides and Glycoconjugates. Adv Carbohydr Chem Biochem 2016; 73:73-116. [PMID: 27816108 DOI: 10.1016/bs.accb.2016.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Recent advances in glycobiology have implicated essential roles of oligosaccharides and glycoconjugates in many important biological recognition processes, including intracellular signaling, cell adhesion, cell differentiation, cancer progression, host-pathogen interactions, and immune responses. A detailed understanding of the biological functions, as well as the development of carbohydrate-based therapeutics, often requires structurally well-defined oligosaccharides and glycoconjugates, which are usually difficult to isolate in pure form from natural sources. To meet with this urgent need, chemical and chemoenzymatic synthesis has become increasingly important as the major means to provide homogeneous compounds for functional glycocomics studies and for drug/vaccine development. Chemoenzymatic synthesis, an approach that combines chemical synthesis and enzymatic manipulations, is often the method of choice for constructing complex oligosaccharides and glycoconjugates that are otherwise difficult to achieve by purely chemical synthesis. Among these, endoglycosidases, a class of glycosidases that hydrolyze internal glycosidic bonds in glycoconjugates and polysaccharides, are emerging as a very attractive class of enzymes for synthetic purposes, due to their transglycosylation activity and their capability of transferring oligosaccharide units en bloc in a single step, in contrast to the limitation of monosaccharide transfers by common glycosyltransferases. In this chapter, we provide an overview on the application of endoglycosidases for the synthesis of complex carbohydrates, including oligosaccharides, polysaccharides, glycoproteins, glycolipids, proteoglycans, and other biologically relevant polysaccharides. The scope, limitation, and future directions of endoglycosidase-catalyzed synthesis are discussed.
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Affiliation(s)
- Chao Li
- University of Maryland, College Park, MD, United States
| | - Lai-Xi Wang
- University of Maryland, College Park, MD, United States
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9
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Yamaguchi T, Amin MN, Toonstra C, Wang LX. Chemoenzymatic Synthesis and Receptor Binding of Mannose-6-Phosphate (M6P)-Containing Glycoprotein Ligands Reveal Unusual Structural Requirements for M6P Receptor Recognition. J Am Chem Soc 2016; 138:12472-85. [PMID: 27500601 DOI: 10.1021/jacs.6b05762] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mannose-6-phosphate (M6P)-terminated oligosaccharides are important signals for M6P-receptor-mediated targeting of newly synthesized hydrolases from Golgi to lysosomes, but the precise structural requirement for the M6P ligand-receptor recognition has not been fully understood due to the difficulties in obtaining homogeneous M6P-containing glycoproteins. We describe here a chemoenzymatic synthesis of homogeneous phosphoglycoproteins carrying natural M6P-containing N-glycans. The method includes the chemical synthesis of glycan oxazolines with varied number and location of the M6P moieties and their transfer to the GlcNAc-protein by an endoglycosynthase to provide homogeneous M6P-containing glycoproteins. Simultaneous attachment of two M6P-oligosaccahrides to a cyclic polypeptide was also accomplished to yield bivalent M6P-glycopeptides. Surface plasmon resonance binding studies reveal that a single M6P moiety located at the low α-1,3-branch of the oligomannose context is sufficient for a high-affinity binding to receptor CI-MPR, while the presence of a M6P moiety at the α-1,6-branch is dispensable. In addition, a binding study with the bivalent cyclic and linear polypeptides reveals that a close proximity of two M6P-oligosaccharide ligands is critical to achieve high affinity for the CI-MPR receptor. Taken together, the present study indicates that the location and valency of the M6P moieties and the right oligosaccharide context are all critical for high-affinity binding with the major M6P receptor. The chemoenzymatic method described here provides a new avenue for glycosylation remodeling of recombinant enzymes to enhance the uptake and delivery of enzymes to lysosomes in enzyme replacement therapy for the treatment of lysosomal storage diseases.
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Affiliation(s)
- Takahiro Yamaguchi
- Institute of Human Virology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States
| | - Mohammed N Amin
- Institute of Human Virology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States.,Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Christian Toonstra
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Lai-Xi Wang
- Institute of Human Virology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States.,Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
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10
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Mende M, Bednarek C, Wawryszyn M, Sauter P, Biskup MB, Schepers U, Bräse S. Chemical Synthesis of Glycosaminoglycans. Chem Rev 2016; 116:8193-255. [DOI: 10.1021/acs.chemrev.6b00010] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Marco Mende
- Institute
of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Christin Bednarek
- Institute
of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Mirella Wawryszyn
- Institute
of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Paul Sauter
- Institute
of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Moritz B. Biskup
- Division
2—Informatics, Economics and Society, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, D-76131 Karlsruhe, Germany
| | - Ute Schepers
- Institute
of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Stefan Bräse
- Institute
of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
- Institute
of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
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11
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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] [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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12
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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] [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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13
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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. [DOI: 10.1002/ange.201600817] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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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14
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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] [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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Wang LX, Amin MN. Chemical and chemoenzymatic synthesis of glycoproteins for deciphering functions. ACTA ACUST UNITED AC 2015; 21:51-66. [PMID: 24439206 DOI: 10.1016/j.chembiol.2014.01.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 12/31/2013] [Accepted: 01/02/2014] [Indexed: 12/11/2022]
Abstract
Glycoproteins are an important class of biomolecules involved in a number of biological recognition processes. However, natural and recombinant glycoproteins are usually produced as mixtures of glycoforms that differ in the structures of the pendent glycans, which are difficult to separate in pure glycoforms. As a result, synthetic homogeneous glycopeptides and glycoproteins have become indispensable probes for detailed structural and functional studies. A number of elegant chemical and biological strategies have been developed for synthetic construction of tailor-made, full-size glycoproteins to address specific biological problems. In this review, we highlight recent advances in chemical and chemoenzymatic synthesis of homogeneous glycoproteins. Selected examples are given to demonstrate the applications of tailor-made, glycan-defined glycoproteins for deciphering glycosylation functions.
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Affiliation(s)
- Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Mohammed N Amin
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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16
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Okamoto R, Izumi M, Kajihara Y. Decoration of proteins with sugar chains: recent advances in glycoprotein synthesis. Curr Opin Chem Biol 2014; 22:92-9. [DOI: 10.1016/j.cbpa.2014.09.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 09/20/2014] [Accepted: 09/22/2014] [Indexed: 12/19/2022]
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17
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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] [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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18
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 12/16/2022]
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Abstract
The synthetic application of endohexosaminidase enzymes (e.g., Endo A, Endo M, Endo D) promises to allow ready access to a wide variety of defined homogeneous glycoproteins and glycopeptides. The use ofN-glycan oligosaccharides that are activated at the reducing terminus as oxazolines allows their high-yielding attachment to almost any amino acid, peptide, or protein that contains a GlcNAc residue as an acceptor. A wide variety of oxazoline donors are readily available, either by total synthesis or by isolation of the corresponding oligosaccharide from natural sources and then conversion to the oxazoline in water. The synthetic potential of the enzymes is particularly augmented by the production of mutant glycosynthases, the use of which allows the synthesis of a wide variety of glycopeptides and glycoproteins bearing defined homogeneousN-glycan structures.
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21
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Recent advances in glycotechnology for glycoconjugate synthesis using microbial endoglycosidases. Biotechnol Lett 2013; 35:1733-43. [PMID: 23801123 DOI: 10.1007/s10529-013-1272-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 06/11/2013] [Indexed: 01/10/2023]
Abstract
Biotechnology associated with synthesis of glycopeptides and glycoproteins has recently advanced as glycotechnology. Studies toward glycotechonology include the artificial modification of sugar chains in glycoconjugates to improve their function because the physiological importance of sugar chains in living organisms is well recognized. Methods involving addition of oligosaccharides to peptides and proteins have attracted attention as efficient techniques in glycotechnology, especially those involving the transglycosylation activities of microbial endoglycosidases. The exploration of oligosaccharide oxazolines as donor substrates for the transglycosylation of endoglycosidases has significantly enhanced the efficiency of these processes. Moreover, discovery of novel endoglycosidase mutants with glycosynthase-like activity has made it possible to effectively synthesize large quantities of glycopeptides, as well as homogeneous glycoprotein. The use of mutant enzymes and oligosaccharide oxazolines has led to development of practical applications for the synthesis of bioactive glycopeptides and therapeutic glycoproteins as bio-medicines.
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22
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Chemoenzymatic synthesis and lectin recognition of a selectively fluorinated glycoprotein. Bioorg Med Chem 2013; 21:4768-77. [PMID: 23566760 DOI: 10.1016/j.bmc.2013.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/25/2013] [Accepted: 03/06/2013] [Indexed: 11/22/2022]
Abstract
A chemoenzymatic glycosylation remodeling method for the synthesis of selectively fluorinated glycoproteins is described. The method consists of chemical synthesis of a fluoroglycan oxazoline and its use as donor substrate for endoglycosidase (ENGase)-catalyzed transglycosylation to a GlcNAc-protein to form a homogeneous fluoroglycoprotein. The approach was exemplified by the synthesis of fluorinated glycoforms of ribonuclease B (RNase B). An interesting finding was that fluorination at the C-6 of the 6-branched mannose moiety in the Man3GlcNAc core resulted in significantly enhanced reactivity of the substrate in enzymatic transglycosylation. A structural analysis suggests that the enhancement in reactivity may come from favorable hydrophobic interactions between the fluorine and a tyrosine residue in the catalytic site of the enzyme (Endo-A). SPR analysis of the binding of the fluorinated glycoproteins with lectin concanavalin A (con A) revealed the importance of the 6-hydroxyl group on the α-1,6-branched mannose moiety in con A recognition. The present study establishes a facile method for preparation of selectively fluorinated glycoproteins that can serve as valuable probes for elucidating specific carbohydrate-protein interactions.
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Lomino JV, Naegeli A, Orwenyo J, Amin MN, Aebi M, Wang LX. A two-step enzymatic glycosylation of polypeptides with complex N-glycans. Bioorg Med Chem 2013; 21:2262-2270. [PMID: 23477942 DOI: 10.1016/j.bmc.2013.02.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 02/02/2013] [Accepted: 02/11/2013] [Indexed: 11/30/2022]
Abstract
A chemoenyzmatic method for direct glycosylation of polypeptides is described. The method consists of two site-specific enzymatic glycosylation steps: introduction of a glucose moiety at the consensus N-glycosylation sequence (NXS/T) in a polypeptide by an N-glycosyltransferase (NGT) and attachment of a complex N-glycan to the glucose primer by an endoglycosidase (ENGase)-catalyzed transglycosylation. Our experiments demonstrated that a relatively small excess of the UDP-Glc (the donor substrate) was sufficient for an effective glucosylation of polypeptides by the NGT, and different high-mannose and complex type N-glycans could be readily transferred to the glucose moiety by ENGases to provide full-size glycopeptides. The usefulness of the chemoenzymatic method was exemplified by an efficient synthesis of a complex glycoform of polypeptide C34, a potent HIV inhibitor derived from HIV-1 gp41. A comparative study indicated that the Glc-peptide was equally efficient as the natural GlcNAc-peptide to serve as an acceptor in the transglycosylation with sugar oxazoline as the donor substrate. Interestingly, the Glc-Asn linked glycopeptide was completely resistant to PNGase F digestion, in contrast to the GlcNAc-Asn linked natural glycopeptide that is an excellent substrate for hydrolysis. In addition, the Glc-Asn linked glycopeptide showed at least 10-fold lower hydrolytic activity toward Endo-M than the natural GlcNAc-Asn linked glycopeptide. The chemoenzymatic glycosylation method described here provides an efficient way to introducing complex N-glycans into polypeptides, for gain of novel properties that could be valuable for drug discovery.
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Affiliation(s)
- Joseph V Lomino
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Andreas Naegeli
- Institute of Microbiology, Dept. of Biology, ETH Zürich, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland
| | - Jared Orwenyo
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Mohammed N Amin
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Markus Aebi
- Institute of Microbiology, Dept. of Biology, ETH Zürich, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland
| | - Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
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24
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Fan SQ, Huang W, Wang LX. Remarkable transglycosylation activity of glycosynthase mutants of endo-D, an endo-β-N-acetylglucosaminidase from Streptococcus pneumoniae. J Biol Chem 2012; 287:11272-81. [PMID: 22318728 DOI: 10.1074/jbc.m112.340497] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Endo-β-N-acetylglucosaminidase from Streptococcus pneumoniae (Endo-D) is an endoglycosidase capable of hydrolyzing the Fc N-glycan of intact IgG antibodies after sequential removal of the sialic acid, galactose, and internal GlcNAc residues in the N-glycan. Endo-D also possesses transglycosylation activity with sugar oxazoline as the donor substrate, but the transglycosylation yield is low due to enzymatic hydrolysis of the donor substrate and the product. We report here our study on the hydrolytic and transglycosylation activity of recombinant Endo-D and its selected mutants. We found that Endo-D preferred core-fucosylated N-glycan for hydrolysis but favored nonfucosylated GlcNAc acceptor for transglycosylation. Several mutants showed significantly enhanced transglycosylation efficiency over the wild type enzyme. Two mutants (N322Q and N322A) were identified as typical glycosynthases that demonstrated remarkable transglycosylation activity with only marginal or no product hydrolysis activity. Kinetic studies revealed that the N322Q [corrected]and N322A glycosynthases had much higher catalytic efficiency for glycosylating the nonfucosylated GlcNAc acceptor. In comparison, the N322Q was much more efficient than N322A for transglycosylation. However, N322Q and N322A [corrected] could not take more complex N-glycan oxazoline as substrate for transglycosylation, indicating their strict substrate specificity. The usefulness of the N322Q glycosynthase was exemplified by its application for efficient glycosylation remodeling of IgG-Fc domain.
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Affiliation(s)
- Shu-Quan Fan
- Institute of Human Virology, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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25
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Wang LX, Lomino JV. Emerging technologies for making glycan-defined glycoproteins. ACS Chem Biol 2012; 7:110-22. [PMID: 22141574 DOI: 10.1021/cb200429n] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein glycosylation is a common and complex posttranslational modification of proteins, which expands functional diversity while boosting structural heterogeneity. Glycoproteins, the end products of such a modification, are typically produced as mixtures of glycoforms possessing the same polypeptide backbone but differing in the site of glycosylation and/or in the structures of pendant glycans, from which single glycoforms are difficult to isolate. The urgent need for glycan-defined glycoproteins in both detailed structure-function relationship studies and therapeutic applications has stimulated an extensive interest in developing various methods for manipulating protein glycosylation. This review highlights emerging technologies that hold great promise in making a variety of glycan-defined glycoproteins, with a particular emphasis in the following three areas: specific glycoengineering of host biosynthetic pathways, in vitro chemoenzymatic glycosylation remodeling, and chemoselective and site-specific glycosylation of proteins.
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Affiliation(s)
- Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Joseph V. Lomino
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
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26
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Affiliation(s)
- Ryan M Schmaltz
- The Department of Chemistry and Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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27
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Amin MN, Huang W, Mizanur RM, Wang LX. Convergent synthesis of homogeneous Glc1Man9GlcNAc2-protein and derivatives as ligands of molecular chaperones in protein quality control. J Am Chem Soc 2011; 133:14404-17. [PMID: 21819116 DOI: 10.1021/ja204831z] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A detailed understanding of the molecular mechanism of chaperone-assisted protein quality control is often hampered by the lack of well-defined homogeneous glycoprotein probes. We describe here a highly convergent chemoenzymatic synthesis of the monoglucosylated glycoforms of bovine ribonuclease (RNase) as specific ligands of lectin-like chaperones calnexin (CNX) and calreticulin (CRT) that are known to recognize the monoglucosylated high-mannose oligosaccharide component of glycoproteins in protein folding. The synthesis of a selectively modified glycoform Gal(1)Glc(1)Man(9)GlcNAc(2)-RNase was accomplished by chemical synthesis of a large N-glycan oxazoline and its subsequent enzymatic ligation to GlcNAc-RNase under the catalysis of a glycosynthase. Selective removal of the terminal galactose by a β-galactosidase gave the Glc(1)Man(9)GlcNAc(2)-RNase glycoform in excellent yield. CD spectroscopic analysis and RNA-hydrolyzing assay indicated that the synthetic RNase glycoforms maintained essentially the same global conformations and were fully active as the natural bovine ribonuclease B. SPR binding studies revealed that the Glc(1)Man(9)GlcNAc(2)-RNase had high affinity to lectin CRT, while the synthetic Man(9)GlcNAc(2)-RNase glycoform and natural RNase B did not show CRT-binding activity. These results confirmed the essential role of the glucose moiety in the chaperone molecular recognition. Interestingly, the galactose-masked glycoform Gal(1)Glc(1)Man(9)GlcNAc(2)-RNase also showed significant affinity to lectin CRT, suggesting that a galactose β-1,4-linked to the key glucose moiety does not significantly block the lectin binding. These synthetic homogeneous glycoprotein probes should be valuable for a detailed mechanistic study on how molecular chaperones work in concert to distinguish between misfolded and folded glycoproteins in the protein quality control cycle.
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Affiliation(s)
- Mohammed N Amin
- Institute of Human Virology, Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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28
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Schiel JE, Lowenthal MS, Phinney KW. Mass spectrometry characterization for chemoenzymatic glycoprotein synthesis. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:649-657. [PMID: 21706674 DOI: 10.1002/jms.1934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The current project describes the chemoenzymatic modification of bovine ribonuclease B (RNase B) to contain a single glycosylation site with a known glycan. A reactive disaccharide oxazoline derivative was synthesized and stereospecifically added to deglycosylated RNase B through endo-β-N-acetylglucosaminidase M catalyzed chemoenzymatic transglycosylation. Oxazoline formation conditions were optimized using mass spectrometry, and the product verified based on its collision-induced dissociation (CID) mass spectrum. Enzymatic removal of native glycans as well as formation of the desired homogeneous product was also monitored using mass spectrometry. LC-MS(n) using four sequential rounds of CID was used to verify that the original glycosylation site had been reorganized to contain the new glycan. The techniques described herein are not limited to this analyte or glycan and should be amenable to the synthesis of numerous homogeneous glycoconjugates with judicious choice of enzyme/substrate combinations. The combined use of chemoenzymatic synthesis and mass spectrometry-based characterization shows promise for the development of homogeneous glycoprotein reference materials. A well-defined glycoprotein standard containing a single glycan of known composition, linkage and stereochemistry would be of great value for the comparison and evaluation of glycoprotein analysis techniques.
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Affiliation(s)
- John E Schiel
- Analytical Chemistry Division, National Institute of Standards and Technology,100 Bureau Drive, Stop 8392, Gaithersburg, MD 20899, USA.
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29
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Huang W, Li J, Wang LX. Unusual transglycosylation activity of Flavobacterium meningosepticum endoglycosidases enables convergent chemoenzymatic synthesis of core fucosylated complex N-glycopeptides. Chembiochem 2011; 12:932-41. [PMID: 21374780 DOI: 10.1002/cbic.201000763] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Indexed: 11/05/2022]
Abstract
Structurally well defined, homogeneous glycopeptides and glycoproteins are indispensable tools for functional glycomics studies. By screening of various endo-β-N-acetylglucosaminidases through the use of appropriate synthetic donor and acceptor substrates, we have found that the Flavobacterium meningosepticum endo-β-N-acetyl-glucosaminidases (GH family 18), including Endo-F2 and Endo-F3, were able to glycosylate α-1,6-fucosylated GlcNAc derivative to provide natural, core-fucosylated complex-type N-glycopeptides. The Endo-F2 and Endo-F3 were efficient for transferring both sialylated and asia-lylated glycans and were highly specific for an α-1,6-fucosylated GlcNAc-peptide as acceptor for transglycosylation, showing only marginal activity with non-fucosylated GlcNAc-peptides. In contrast, we found that the commonly used endoglycosidases such as Endo-A and Endo-M, which belong to GH family 85, were unable to take α-1,6-fucosyl-GlcNAc derivative as acceptors for transglycosylation. The novel activity of Endo-F2 and Endo-F3 was successfully applied for a highly convergent chemoenzymatic synthesis of a full-sized CD52 glycopeptide antigen carrying both terminal sialic acid and core fucose. This is the first report on endoglycosidases that are able to glycosylate α-1,6-fucosylated GlcNAc derivatives to form natural core-fucosylated glycopeptides.
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (USA), Fax: (+1) 410-706-4694
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30
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Wang LX. The Amazing Transglycosylation Activity of Endo-β-N-acetylglucosaminidases. TRENDS GLYCOSCI GLYC 2011; 23:33-52. [PMID: 25309039 DOI: 10.4052/tigg.23.33] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Major advances have been made in exploring the transglycosylation activity of endo-β-N-acetylglucosaminidases (ENGases) for synthetic purpose. The exploration of synthetic sugar oxazolines as donor substrates for the ENGase-catalyzed transglycosylation has expanded the substrate availability and significantly enhanced the overall transglycosylation efficiency. On the other hand, site-directed mutagenesis in combination with activity screening has led to the discovery of the first generation ENGase-based glycosynthases that can use highly active sugar oxazolines as substrates for transglycosylation but lack hydrolytic activity on the ground-state products. ENGases have shown amazing flexibility in transglycosylation and possess much broader substrate specificity than previously thought. Now the ENGase-based chemoenzymatic method has been extended to the synthesis of a range of complex carbohydrates, including homogeneous glycopeptides, glycoproteins carrying well-defined glycans, novel oligosaccharide clusters, unusually glycosylated natural products, and even polysaccharides. This article highlights recent advances related to ENGase-catalyzed transglycosylation with a focus on their synthetic potential.
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Affiliation(s)
- Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA, Tel: 410-706-4982
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31
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Fairbanks AJ. Endohexosaminidase catalysed glycosylation with oxazoline donors: The development of robust biocatalytic methods for synthesis of defined homogeneous glycoconjugates. CR CHIM 2011. [DOI: 10.1016/j.crci.2010.05.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Huang W, Zhang X, Ju T, Cummings RD, Wang LX. Expeditious chemoenzymatic synthesis of CD52 glycopeptide antigens. Org Biomol Chem 2010; 8:5224-33. [PMID: 20848033 DOI: 10.1039/c0ob00341g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CD52 is a glycosylphosphatidylinositol (GPI)-anchored glycopeptide antigen found on sperm cells and human lymphocytes. Recent structural studies indicate that sperm-associated CD52 antigen carries both a complex type N-glycan and an O-glycan on the polypeptide backbone. To facilitate functional and immunological studies of distinct CD52 glycoforms, we report in this paper the first chemoenzymatic synthesis of homogeneous CD52 glycoforms carrying both N- and O-glycans. The synthetic strategy consists of two key steps: monosaccharide primers GlcNAc and GalNAc were first installed at the pre-determined N- and O-glycosylation sites by a facile solid-phase peptide synthesis, and then the N- and O-glycans were extended by respective enzymatic glycosylations. It was found that the endoglycosidase-catalyzed transglycosylation allowed efficient attachment of an intact N-glycan in a single step at the N-glycosylation site, while the recombinant human T-synthase could independently extend the O-linked GalNAc to form the core 1 O-glycan. This chemoenzymatic approach is highly convergent and permits easy construction of various homogeneous CD52 glycoforms from a common polypeptide precursor. In addition, the introduction of a latent thiol group in the form of protected cysteamine at the C-terminus of the CD52 glycoforms will enable site-specific conjugation to a carrier protein to provide immunogens for generating CD52 glycoform-specific antibodies for functional studies.
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Huang W, Yang Q, Umekawa M, Yamamoto K, Wang LX. Arthrobacter endo-beta-N-acetylglucosaminidase shows transglycosylation activity on complex-type N-glycan oxazolines: one-pot conversion of ribonuclease B to sialylated ribonuclease C. Chembiochem 2010; 11:1350-5. [PMID: 20486148 PMCID: PMC3444296 DOI: 10.1002/cbic.201000242] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Indexed: 11/10/2022]
Abstract
Asparagine-linked glycosylation is a major form of posttranslational modifications, which plays important roles in protein folding, intracellular signaling, and a number of other biological recognition events [1 ]. Glycoproteins are often characterized by their structural micro-heterogeneity where different glycoforms have the same polypeptide backbone but differ in the pendant oligosaccharides. Of particular interest are the findings that subtle difference in the attached glycans can have a significant impact on the biological functions of a given glycoprotein [2 , 3 ]. The urgent need of pure glycoforms for functional studies and biomedical applications has stimulated a great interest in exploring new methods for making homogeneous glycoproteins [4 ]. Major advances include the application of native chemical ligation and expressed protein ligation for constructing full-size glycoproteins [5 –7 ], chemoselective ligation to introduce homogeneous glycans [8 ], and the engineering of yeast glycosylation pathways to produce single glycoforms [9 ]. Yet another interesting advance in the field is the endoglycosidase-catalyzed transglycosylation for glycosylation engineering and glycoprotein synthesis [10 –16 ].
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA, Fax: (+)1-410-706-4694
| | - Qiang Yang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA, Fax: (+)1-410-706-4694
| | - Midori Umekawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Kenji Yamamoto
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA, Fax: (+)1-410-706-4694
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Jiménez-Castells C, Defaus S, Andreu D, Gutiérrez-Gallego R. Recent progress in the field of neoglycoconjugate chemistry. Biomol Concepts 2010; 1:85-96. [DOI: 10.1515/bmc.2010.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractGlycosylation is probably the most complex secondary gene event that affects the vast majority of proteins in nature resulting in the occurrence of a heterogeneous mixture of glycoforms for a single protein. Many functions are exerted by single monosaccharides, well-defined oligosaccharides, or larger glycans present in these glycoproteins. To unravel these functions it is of the utmost importance to prepare well-defined single glycans conjugated to the underlying aglycon. In this review, the most recent developments are described to address the preparation of carbohydrate-amino acid (glyco-conjugates). Naturally occurring N- and O-linked glycosylation are described and the preparation of non-natural sugar-amino acid linkages are also included.
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Affiliation(s)
- Carmen Jiménez-Castells
- 1Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Sira Defaus
- 1Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - David Andreu
- 1Department of Experimental and Health Sciences, Pompeu Fabra University, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain
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Huang W, Wang D, Yamada M, Wang LX. Chemoenzymatic synthesis and lectin array characterization of a class of N-glycan clusters. J Am Chem Soc 2010; 131:17963-71. [PMID: 19916512 DOI: 10.1021/ja9078539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
N-Glycans are major components of many glycoproteins. These sugar moieties are frequently involved in important physiological and disease processes via their interactions with a variety of glycan-binding proteins (GBP). Clustering effect is an important feature in many glycan-lectin interactions. We describe in this paper a chemoenzymatic synthesis of novel N-glycan clusters using a tandem endoglycosidase-catalyzed transglycosylation. It was found that the internal beta-1,2-linked GlcNAc moieties in the N-glycan core, once exposed in the nonreducing terminus, was able to serve as acceptors for transglycosylation catalyzed by Endo-A and EndoM-N175A. This efficient chemoenzymatic method allows a quick extension of the sugar chains to form a class of glycan clusters in which sugar residues are all connected by native glycosidic linkages found in natural N-glycans. In addition, a discriminative enzymatic reaction at the two GlcNAc residues could be fulfilled to afford novel hybrid clusters. Lectin microarray studies revealed unusual properties in glyco-epitope expression by this panel of structurally well-defined synthetic N-glycans. These new compounds are likely valuable for functional glycomics studies to unveil new functions of both glycans and carbohydrate-binding proteins.
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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36
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Makino A, Kobayashi S. Chemistry of 2-oxazolines: A crossing of cationic ring-opening polymerization and enzymatic ring-opening polyaddition. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.23906] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Kobayashi S, Makino A. Enzymatic polymer synthesis: an opportunity for green polymer chemistry. Chem Rev 2010; 109:5288-353. [PMID: 19824647 DOI: 10.1021/cr900165z] [Citation(s) in RCA: 409] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Shiro Kobayashi
- R & D Center for Bio-based Materials, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
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38
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Conroy T, Jolliffe KA, Payne RJ. Synthesis of N-linked glycopeptides via solid-phase aspartylation. Org Biomol Chem 2010; 8:3723-33. [DOI: 10.1039/c003673k] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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39
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Parsons TB, Patel MK, Boraston AB, Vocadlo DJ, Fairbanks AJ. Streptococcus pneumoniae endohexosaminidase D; feasibility of using N-glycan oxazoline donors for synthetic glycosylation of a GlcNAc-asparagine acceptor. Org Biomol Chem 2010; 8:1861-9. [DOI: 10.1039/b926078a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Heidecke CD, Parsons TB, Fairbanks AJ. Endohexosaminidase-catalysed glycosylation with oxazoline donors: effects of organic co-solvent and pH on reactions catalysed by Endo A and Endo M. Carbohydr Res 2009; 344:2433-8. [PMID: 19889401 DOI: 10.1016/j.carres.2009.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 09/07/2009] [Accepted: 09/13/2009] [Indexed: 10/20/2022]
Abstract
The synthetic efficiency of endohexosaminidase-catalysed glycosylation reactions using N-glycan oxazolines as donors was investigated as two reaction parameters were varied. Both the addition of quantities of an organic co-solvent and modulation of reaction pH between 6.5 and 8.0 were found to have different effects on reactions catalysed by either Endo A (and two available mutants) or Endo M, indicating subtle differences between these two family GH85 enzymes. Fine tuning of reaction pH, or the addition of quantities of an organic co-solvent, resulted in beneficial increases in achievable synthetic efficiency by effecting a reduction in the rate of competitive hydrolytic processes.
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Affiliation(s)
- Christoph D Heidecke
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
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41
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Wang LX, Huang W. Enzymatic transglycosylation for glycoconjugate synthesis. Curr Opin Chem Biol 2009; 13:592-600. [PMID: 19766528 DOI: 10.1016/j.cbpa.2009.08.014] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 08/15/2009] [Accepted: 08/21/2009] [Indexed: 11/24/2022]
Abstract
Remarkable advances have been made in recent years in exploiting the transglycosylation activity of glycosidases and glycosynthase mutants for oligosaccharide and glycoconjugate synthesis. New glycosynthases were generated from retaining glycosidases, inverting glycosidases, and those that proceed in a mechanism of substrate-assisted catalysis. Directed evolution coupled with elegant screening methods has led to the discovery of an expanding number of glycosynthase mutants that show improved catalytic activity and/or altered substrate specificity. In particular, enzymatic transglycosylation strategy has been recently extended to the synthesis of complex glycoconjugates, including glycosphingolipids, N-glycoproteins, and other glycosylated natural products.
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Affiliation(s)
- Lai-Xi Wang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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42
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Ling Z, Suits MD, Bingham RJ, Bruce NC, Davies GJ, Fairbanks AJ, Moir JW, Taylor EJ. The X-ray Crystal Structure of an Arthrobacter protophormiae Endo-β-N-Acetylglucosaminidase Reveals a (β/α)8 Catalytic Domain, Two Ancillary Domains and Active Site Residues Key for Transglycosylation Activity. J Mol Biol 2009; 389:1-9. [PMID: 19327363 DOI: 10.1016/j.jmb.2009.03.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 03/16/2009] [Accepted: 03/19/2009] [Indexed: 10/21/2022]
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43
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Huang W, Li C, Li B, Umekawa M, Yamamoto K, Zhang X, Wang LX. Glycosynthases enable a highly efficient chemoenzymatic synthesis of N-glycoproteins carrying intact natural N-glycans. J Am Chem Soc 2009; 131:2214-23. [PMID: 19199609 DOI: 10.1021/ja8074677] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Homogeneous N-glycoproteins carrying defined natural N-glycans are essential for detailed structural and functional studies. The transglycosylation activity of the endo-beta-N-acetylglucosaminidases from Arthrobacter protophormiae (Endo-A) and Mucor hiemalis (Endo-M) holds great potential for glycoprotein synthesis, but the wild-type enzymes are not practical for making glycoproteins carrying native N-glycans because of their predominant activity for product hydrolysis. In this article, we report studies of two endoglycosidase-based glycosynthases, EndoM-N175A and EndoA-N171A, and their usefulness in constructing homogeneous N-glycoproteins carrying natural N-glycans. The oligosaccharide oxazoline corresponding to the biantennary complex-type N-glycan was synthesized and tested with the two glycosynthases. The EndoM-N175A mutant was able to efficiently transfer the complex-type glycan oxazoline to a GlcNAc peptide and GlcNAc-containing ribonuclease to form the corresponding homogeneous glycopeptide/glycoprotein. The EndoA-N171A mutant did not recognize the complex-type N-glycan oxazoline but could efficiently use the high-mannose-type glycan oxazoline for transglycosylation. These mutants possess the transglycosylation activity but lack the hydrolytic activity toward the product. Kinetic studies revealed that the dramatically enhanced synthetic efficiency of the EndoA-N171A mutant was due to the significantly reduced hydrolytic activity toward both the Man(9)GlcNAc oxazoline and the product as well as to its enhanced activity for transglycosylation. Thus, the two mutants described here represent the first endoglycosidase-based glycosynthases enabling a highly efficient synthesis of homogeneous natural N-glycoproteins.
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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44
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Affiliation(s)
- David P Gamblin
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom
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45
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Abbott DW, Macauley MS, Vocadlo DJ, Boraston AB. Streptococcus pneumoniae endohexosaminidase D, structural and mechanistic insight into substrate-assisted catalysis in family 85 glycoside hydrolases. J Biol Chem 2009; 284:11676-89. [PMID: 19181667 DOI: 10.1074/jbc.m809663200] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endo-beta-d-glucosaminidases from family 85 of glycoside hydrolases (GH85 endohexosaminidases) act to cleave the glycosidic linkage between the two N-acetylglucosamine units that make up the chitobiose core of N-glycans. Endohexosaminidase D (Endo-D), produced by Streptococcus pneumoniae, is believed to contribute to the virulence of this organism by playing a role in the deglycosylation of IgG antibodies. Endohexosaminidases have received significant attention for this reason and, moreover, because they are powerful tools for chemoenzymatic synthesis of proteins having defined glycoforms. Here we describe mechanistic and structural studies of the catalytic domain (SpGH85) of Endo-D that provide compelling support for GH85 enzymes using a catalytic mechanism involving substrate-assisted catalysis. Furthermore, the structure of SpGH85 in complex with the mechanism-based competitive inhibitor NAG-thiazoline (K(d) = 28 microm) provides a coherent rationale for previous mutagenesis studies of Endo-D and other related GH85 enzymes. We also find GH85, GH56, and GH18 enzymes have a similar configuration of catalytic residues. Notably, GH85 enzymes have an asparagine in place of the aspartate residue found in these other families of glycosidases. We propose that this residue, as the imidic acid tautomer, acts analogously to the key catalytic aspartate of GH56 and GH18 enzymes. This topographically conserved arrangement of the asparagine residue and a conserved glutamic acid, coupled with previous kinetic studies, suggests these enzymes may use an unusual proton shuttle to coordinate effective general acid and base catalysis to aid cleavage of the glycosidic bond. These results collectively provide a blueprint that may be used to facilitate protein engineering of these enzymes to improve their function as biocatalysts for synthesizing glycoproteins having defined glycoforms and also may serve as a guide for generating inhibitors of GH85 enzymes.
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Affiliation(s)
- D Wade Abbott
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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46
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Ochiai H, Huang W, Wang LX. Endo-beta-N-acetylglucosaminidase-catalyzed polymerization of beta-Glcp-(1-->4)-GlcpNAc oxazoline: a revisit to enzymatic transglycosylation. Carbohydr Res 2009; 344:592-8. [PMID: 19193364 DOI: 10.1016/j.carres.2009.01.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Revised: 01/09/2009] [Accepted: 01/14/2009] [Indexed: 10/21/2022]
Abstract
An alternative synthesis of beta-Glcp-(1-->4)-GlcpNAc oxazoline is described, and its enzymatic reaction with the endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) was re-investigated. Under normal transglycosylation conditions with a catalytic amount of enzyme, Endo-A showed only marginal activity for transglycosylation with the disaccharide oxazoline, consistent with our previous observations. However, when used in a relatively large quantity, Endo-A could promote the transglycosylation of the disaccharide oxazoline to a GlcpNAc-Asn acceptor. In addition to the initial transglycosylation product, a series of large oligosaccharides were also formed due to the tandem transglycosylation to the terminal glucose residues in the intermediate products. In the absence of an external acceptor, Endo-A could polymerize the disaccharide oxazoline to form oligo- and polysaccharides having the -4-beta-(Glcp-(1-->4)-beta -GlcpNAc)-1-repeating units. This is the first example of an endo-beta-N-acetylglucosaminidase-promoted polymerization of activated oligosaccharide substrates. This enzymatic polymerization may find useful applications for the synthesis of novel artificial polysaccharides.
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Affiliation(s)
- Hirofumi Ochiai
- Institute of Human Virology and Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, United States
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47
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Parsons TB, Moir JWB, Fairbanks AJ. Synthesis of a truncated bi-antennary complex-type N-glycan oxazoline; glycosylation catalysed by the endohexosaminidases Endo A and Endo M. Org Biomol Chem 2009. [DOI: 10.1039/b907273j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Ochiai H, Huang W, Wang LX. Expeditious chemoenzymatic synthesis of homogeneous N-glycoproteins carrying defined oligosaccharide ligands. J Am Chem Soc 2008; 130:13790-803. [PMID: 18803385 DOI: 10.1021/ja805044x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient chemoenzymatic method for the construction of homogeneous N-glycoproteins was described that explores the transglycosylation activity of the endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) with synthetic sugar oxazolines as the donor substrates. First, an array of large oligosaccharide oxazolines were synthesized and evaluated as substrates for the Endo-A-catalyzed transglycosylation by use of ribonuclease B as a model system. The experimental results showed that Endo-A could tolerate modifications at the outer mannose residues of the Man3GlcNAc-oxazoline core, thus allowing introduction of large oligosaccharide ligands into a protein and meanwhile preserving the natural, core N-pentasaccharide (Man3GlcNAc2) structure in the resulting glycoprotein upon transglycosylation. In addition to ligands for galectins and mannose-binding lectins, azido functionality could be readily introduced at the N-pentasaccharide (Man3GlcNAc2) core by use of azido-containing Man3GlcNAc oxazoline as the donor substrate. The introduction of azido functionality permits further site-specific modifications of the resulting glycoproteins, as demonstrated by the successful attachment of two copies of alphaGal epitopes to ribonuclease B. This study reveals a broad substrate specificity of Endo-A for transglycosylation, and the chemoenzymatic method described here points to a new avenue for quick access to various homogeneous N-glycoproteins for structure-activity relationship studies and for biomedical applications.
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Affiliation(s)
- Hirofumi Ochiai
- Institute of Human Virology, Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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49
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Huang W, Ochiai H, Zhang X, Wang LX. Introducing N-glycans into natural products through a chemoenzymatic approach. Carbohydr Res 2008; 343:2903-13. [PMID: 18805520 DOI: 10.1016/j.carres.2008.08.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Revised: 08/23/2008] [Accepted: 08/31/2008] [Indexed: 10/21/2022]
Abstract
The present study describes an efficient chemoenzymatic method for introducing a core N-glycan of glycoprotein origin into various lipophilic natural products. It was found that the endo-beta-N-acetylglucosaminidase from Arthrobactor protophormiae (Endo-A) had broad substrate specificity and can accommodate a wide range of glucose (Glc)- or N-acetylglucosamine (GlcNAc)-containing natural products as acceptors for transglycosylation, when an N-glycan oxazoline was used as a donor substrate. Using lithocholic acid as a model compound, we have shown that introduction of an N-glycan could be achieved by a two-step approach: chemical glycosylation to introduce a monosaccharide (Glc or GlcNAc) as a handle, and then Endo-A catalyzed transglycosylation to accomplish the site-specific N-glycan attachment. For those natural products that already carry terminal Glc or GlcNAc residues, direct enzymatic transglycosylation using sugar oxazoline as the donor substrate was achievable to introduce an N-glycan. It was also demonstrated that simultaneous double glycosylation could be fulfilled when the natural product contains two Glc residues. This chemoenzymatic method is concise, site-specific, and highly convergent. Because N-glycans of glycoprotein origin can serve as ligands for diverse lectins and cell-surface receptors, introduction of a defined N-glycan into biologically significant natural products may bestow novel properties onto these natural products for drug discovery and development.
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Affiliation(s)
- Wei Huang
- Institute of Human Virology and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
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50
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Wei Y, Li C, Huang W, Li B, Strome S, Wang LX. Glycoengineering of human IgG1-Fc through combined yeast expression and in vitro chemoenzymatic glycosylation. Biochemistry 2008; 47:10294-304. [PMID: 18771295 DOI: 10.1021/bi800874y] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The presence and precise structures of the glycans attached at the Fc domain of monoclonal antibodies play an important role in determining antibodies' effector functions such as antibody-dependent cell cytotoxicity (ADCC), complement activation, and anti-inflammatory activity. This paper describes a novel approach for glycoengineering of human IgG1-Fc that combines high-yield expression of human IgG1-Fc in yeast and subsequent in vitro enzymatic glycosylation, using the endoglycosidase-catalyzed transglycosylation as the key reaction. Human IgG1-Fc was first overproduced in Pichia pastoris. Then the heterogeneous yeast glycans were removed by Endo-H treatment to give the GlcNAc-containing IgG1-Fc as a homodimer. Finally, selected homogeneous glycans were attached to the GlcNAc-primer in the IgG1-Fc through an endoglycosidase-catalyzed transglycosylation, using sugar oxazolines as the donor substrates. It was found that the enzymatic transglycosylation was efficient with native GlcNAc-containing IgG1-Fc homodimer without the need to denature the protein, and the reaction could proceed to completion to give homogeneous glycoforms of IgG1-Fc when an excess of oligosaccharide oxazolines was used as the donor substrates. The binding of the synthetic IgG1-Fc glycoforms to the FcgammaIIIa receptor was also investigated. This novel glycoengineering approach should be useful for providing various homogeneous, natural or synthetic glycoforms of IgG1-Fc for structure-function relationship studies, and for future clinical applications.
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Affiliation(s)
- Yadong Wei
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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