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Ikegaya M, Park EY, Miyazaki T. Structure-function analysis of bacterial GH31 α-galactosidases specific for α-(1→4)-galactobiose. FEBS J 2023; 290:4984-4998. [PMID: 37438884 DOI: 10.1111/febs.16904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/21/2023] [Accepted: 07/10/2023] [Indexed: 07/14/2023]
Abstract
Glycoside hydrolase family 31 (GH31) contains α-glycoside hydrolases with different substrate specificities involved in various physiological functions. This family has recently been classified into 20 subfamilies using sequence similarity networks. An α-galactosidase from the gut bacterium Bacteroides salyersiae (BsGH31_19, which belongs to GH31 subfamily 19) was reported to have hydrolytic activity against the synthetic substrate p- nitrophenyl α-galactopyranoside, but its natural substrate remained unknown. BsGH31_19 shares low sequence identity (around 20%) with other reported GH31 α-galactosidases, PsGal31A from Pseudopedobacter saltans and human myogenesis-regulating glycosidase (MYORG), and was expected to have distinct specificity. Here, we characterized BsGH31_19 and its ortholog from a soil Bacteroidota bacterium, Flavihumibacter petaseus (FpGH31_19), and demonstrated that they showed high substrate specificity against α-(1→4)-linkages in α-(1→4)-galactobiose and globotriose [α-Gal-(1→4)-β-Gal-(1→4)-Glc], unlike PsGal31A and MYORG. The crystallographic analyses of BsGH31_19 and FpGH31_19 showed that their overall structures resemble those of MYORG and form a dimer with an interface different from that of PsGal31A and MYORG dimers. The structures of FpGH31_19 complexed with d-galactose and α-(1→4)-galactobiose revealed that amino acid residues that recognize a galactose residue at subsite +1 are not conserved between FpGH31_19 and BsGH31_19. The tryptophan (Trp153) that recognizes galactose at subsite -1 is homologous to the tryptophan residues in MYORG and α-galactosidases belonging to GH27, GH36, and GH97, but not in the bacterial GH31 member PsGal31A. Our results provide structural insights into molecular diversity and evolutionary relationships in the GH31 α-galactosidase subfamilies and the other α-galactosidase families.
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Affiliation(s)
- Marina Ikegaya
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Japan
| | - Enoch Y Park
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Japan
- Research Institute of Green Science and Technology, Shizuoka University, Japan
| | - Takatsugu Miyazaki
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Japan
- Research Institute of Green Science and Technology, Shizuoka University, Japan
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2
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Yi Z, Chen L, Jin Y, Shen Y, Liu N, Fang Y, Xiao Y, Wang X, Peng K, He K, Zhao H. Insight into broad substrate specificity and synergistic contribution of a fungal α-glucosidase in Chinese Nong-flavor daqu. Microb Cell Fact 2023; 22:114. [PMID: 37322438 DOI: 10.1186/s12934-023-02124-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
BACKGROUND Chinese Nong-favor daqu, the presentative liquor starter of Baijiu, has been enriched with huge amounts of enzymes in degrading various biological macromolecules by openly man-made process for thousand years. According to previous metatranscriptomics analysis, plenty of α-glucosidases were identified to be active in NF daqu and played the key role in degrading starch under solid-state fermentation. However, none of α-glucosidases was characterized from NF daqu, and their actual functions in NF daqu were still unknown. RESULTS An α-glucosidase (NFAg31A, GH31-1 subfamily), the second highest expressed α-glucosidases in starch degradation of NF daqu, was directly obtained by heterologous expression in Escherichia coli BL21 (DE3). NFAg31A exhibited the highest sequence identities of 65.8% with α-glucosidase II from Chaetomium thermophilum, indicating its origin of fungal species, and it showed some similar features with homologous α-glucosidase IIs, i.e., optimal activity at pH ~ 7.0 and litter higher temperature of 45 ℃, well stability at 41.3 ℃ and a broad pH range of pH 6.0 to pH 10.0, and preference on hydrolyzing Glc-α1,3-Glc. Besides this preference, NFAg31A showed comparable activities on Glc-α1,2-Glc and Glc-α1,4-Glc, and low activity on Glc-α1,6-Glc, indicating its broad specificities on α-glycosidic substrates. Additionally, its activity was not stimulated by any of those detected metal ions and chemicals, and could be largely inhibited by glucose under solid-state fermentation. Most importantly, it exhibited competent and synergistic effects with two characterized α-amylases of NF daqu on hydrolyzing starch, i.e., all of them could efficiently degrade starch and malto-saccharides, two α-amylases showed advantage in degrading starch and long-chain malto-saccharides, and NFAg31A played the competent role with α-amylases in degrading short-chain malto-saccharides and the irreplaceable contribution in hydrolyzing maltose into glucose, thus alleviating the product inhibitions of α-amylases. CONCLUSIONS This study provides not only a suitable α-glucosidase in strengthening the quality of daqu, but also an efficient way to reveal roles of the complicated enzyme system in traditional solid-state fermentation. This study would further stimulate more enzyme mining from NF daqu, and promote their actual applications in solid-state fermentation of NF liquor brewing, as well as in other solid-state fermentation of starchy industry in the future.
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Affiliation(s)
- Zhuolin Yi
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Lanchai Chen
- School of Food and Bioengineering, Xihua University, Chengdu, Sichuan, 610039, China
| | - Yanling Jin
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yi Shen
- Sichuan Langjiu Co., Ltd, Gulin, 646523, China
| | - Nian Liu
- Sichuan Food and Fermentation Industry Research & Design Institute, Chengdu, 611130, China
| | - Yang Fang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Yao Xiao
- Analytical and Testing Center, Sichuan University of Science and Engineering, Zigong, 643000, China
| | - Xi Wang
- Sichuan Langjiu Co., Ltd, Gulin, 646523, China
| | - Kui Peng
- Sichuan Food and Fermentation Industry Research & Design Institute, Chengdu, 611130, China
| | - Kaize He
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China
| | - Hai Zhao
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, No. 9 Section 4, Renmin Nan Road, Chengdu, Sichuan, 610041, P.R. China.
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3
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Arumapperuma T, Li J, Hornung B, Soler NM, Goddard-Borger ED, Terrapon N, Williams SJ. A subfamily classification to choreograph the diverse activities within glycoside hydrolase family 31. J Biol Chem 2023; 299:103038. [PMID: 36806678 PMCID: PMC10074150 DOI: 10.1016/j.jbc.2023.103038] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/01/2023] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
The Carbohydrate-Active Enzyme classification groups enzymes that breakdown, assemble, or decorate glycans into protein families based on sequence similarity. The glycoside hydrolases (GH) are arranged into over 170 enzyme families, with some being very large and exhibiting distinct activities/specificities towards diverse substrates. Family GH31 is a large family that contains more than 20,000 sequences with a wide taxonomic diversity. Less than 1% of GH31 members are biochemically characterized and exhibit many different activities that include glycosidases, lyases, and transglycosidases. This diversity of activities limits our ability to predict the activities and roles of GH31 family members in their host organism and our ability to exploit these enzymes for practical purposes. Here, we established a subfamily classification using sequence similarity networks that was further validated by a structural analysis. While sequence similarity networks provide a sequence-based separation, we obtained good segregation between activities among the subfamilies. Our subclassification consists of 20 subfamilies with sixteen subfamilies containing at least one characterized member and eleven subfamilies that are monofunctional based on the available data. We also report the biochemical characterization of a member of the large subfamily 2 (GH31_2) that lacked any characterized members: RaGH31 from Rhodoferax aquaticus is an α-glucosidase with activity on a range of disaccharides including sucrose, trehalose, maltose, and nigerose. Our subclassification provides improved predictive power for the vast majority of uncharacterized proteins in family GH31 and highlights the remaining sequence space that remains to be functionally explored.
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Affiliation(s)
- Thimali Arumapperuma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute and University of Melbourne, Parkville, Victoria, Australia
| | - Jinling Li
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute and University of Melbourne, Parkville, Victoria, Australia
| | - Bastian Hornung
- AFMB, UMR 7257 CNRS Aix-Marseille Univ., USC 1408 INRAE, Marseille, France
| | - Niccolay Madiedo Soler
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Ethan D Goddard-Borger
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Nicolas Terrapon
- AFMB, UMR 7257 CNRS Aix-Marseille Univ., USC 1408 INRAE, Marseille, France
| | - Spencer J Williams
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute and University of Melbourne, Parkville, Victoria, Australia.
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Meek RW, Brockerman J, Fordwour OB, Zandberg WF, Davies GJ, Vocadlo DJ. The primary familial brain calcification-associated protein MYORG is an α-galactosidase with restricted substrate specificity. PLoS Biol 2022; 20:e3001764. [PMID: 36129849 PMCID: PMC9491548 DOI: 10.1371/journal.pbio.3001764] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/25/2022] [Indexed: 11/18/2022] Open
Abstract
Primary familial brain calcification (PFBC) is characterised by abnormal deposits of calcium phosphate within various regions of the brain that are associated with severe cognitive impairments, psychiatric conditions, and movement disorders. Recent studies in diverse populations have shown a link between mutations in myogenesis-regulating glycosidase (MYORG) and the development of this disease. MYORG is a member of glycoside hydrolase (GH) family 31 (GH31) and, like the other mammalian GH31 enzyme α-glucosidase II, this enzyme is found in the lumen of the endoplasmic reticulum (ER). Though presumed to act as an α-glucosidase due to its localization and sequence relatedness to α-glucosidase II, MYORG has never been shown to exhibit catalytic activity. Here, we show that MYORG is an α-galactosidase and present the high-resolution crystal structure of MYORG in complex with substrate and inhibitor. Using these structures, we map detrimental mutations that are associated with MYORG-associated brain calcification and define how these mutations may drive disease progression through loss of enzymatic activity. Finally, we also detail the thermal stabilisation of MYORG afforded by a clinically approved small molecule ligand, opening the possibility of using pharmacological chaperones to enhance the activity of mutant forms of MYORG. MYORG is an enzyme genetically linked to primary familial brain calcification that has historically been presumed to act as an α-glucosidase. This study describes the crystal structure of dimeric MYORG and, surprisingly, reveals it to be an α-galactosidase with restricted specificity.
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Affiliation(s)
- Richard W. Meek
- Department of Chemistry. University of York, York, United Kingdom
| | - Jacob Brockerman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Osei B. Fordwour
- Department of Chemistry, Irving K. Barber Faculty of Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Wesley F. Zandberg
- Department of Chemistry, Irving K. Barber Faculty of Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Gideon J. Davies
- Department of Chemistry. University of York, York, United Kingdom
- * E-mail: (GJD); (DJV)
| | - David J. Vocadlo
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail: (GJD); (DJV)
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5
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Structural basis for proteolytic processing of Aspergillus sojae α-glucosidase L with strong transglucosylation activity. J Struct Biol 2022; 214:107874. [DOI: 10.1016/j.jsb.2022.107874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 11/18/2022]
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Ikegaya M, Moriya T, Adachi N, Kawasaki M, Park EY, Miyazaki T. Structural basis of the strict specificity of a bacterial GH31 α-1,3-glucosidase for nigerooligosaccharides. J Biol Chem 2022; 298:101827. [PMID: 35293315 PMCID: PMC9061262 DOI: 10.1016/j.jbc.2022.101827] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/02/2022] [Accepted: 03/02/2022] [Indexed: 11/26/2022] Open
Abstract
Carbohydrate-active enzymes are involved in the degradation, biosynthesis, and modification of carbohydrates and vary with the diversity of carbohydrates. The glycoside hydrolase (GH) family 31 is one of the most diverse families of carbohydrate-active enzymes, containing various enzymes that act on α-glycosides. However, the function of some GH31 groups remains unknown, as their enzymatic activity is difficult to estimate due to the low amino acid sequence similarity between characterized and uncharacterized members. Here, we performed a phylogenetic analysis and discovered a protein cluster (GH31_u1) sharing low sequence similarity with the reported GH31 enzymes. Within this cluster, we showed that a GH31_u1 protein from Lactococcus lactis (LlGH31_u1) and its fungal homolog demonstrated hydrolytic activities against nigerose [α-D-Glcp-(1→3)-D-Glc]. The kcat/Km values of LlGH31_u1 against kojibiose and maltose were 13% and 2.1% of that against nigerose, indicating that LlGH31_u1 has a higher specificity to the α-1,3 linkage of nigerose than other characterized GH31 enzymes, including eukaryotic enzymes. Furthermore, the three-dimensional structures of LlGH31_u1 determined using X-ray crystallography and cryogenic electron microscopy revealed that LlGH31_u1 forms a hexamer and has a C-terminal domain comprising four α-helices, suggesting that it contributes to hexamerization. Finally, crystal structures in complex with nigerooligosaccharides and kojibiose along with mutational analysis revealed the active site residues involved in substrate recognition in this enzyme. This study reports the first structure of a bacterial GH31 α-1,3-glucosidase and provides new insight into the substrate specificity of GH31 enzymes and the physiological functions of bacterial and fungal GH31_u1 members.
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Affiliation(s)
- Marina Ikegaya
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan
| | - Toshio Moriya
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - Naruhiko Adachi
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
| | - Masato Kawasaki
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan; Department of Materials Structure Science, School of High Energy Accelerator Science, The Graduate University of Advanced Studies (Soken-dai), Tsukuba, Ibaraki, Japan
| | - Enoch Y Park
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan; Research Institute of Green Science and Technology, Shizuoka University, Shizuoka, Japan
| | - Takatsugu Miyazaki
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, Shizuoka, Japan; Research Institute of Green Science and Technology, Shizuoka University, Shizuoka, Japan.
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7
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Miyazaki T, Ikegaya M, Alonso-Gil S. Structural and mechanistic insights into the substrate specificity and hydrolysis of GH31 α-N-acetylgalactosaminidase. Biochimie 2021; 195:90-99. [PMID: 34826537 DOI: 10.1016/j.biochi.2021.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/15/2021] [Accepted: 11/22/2021] [Indexed: 11/02/2022]
Abstract
Glycoside hydrolase family 31 (GH31) is a diversified family of anomer-retaining α-glycoside hydrolases, such as α-glucosidase and α-xylosidase, among others. Recently, GH31 α-N-acetylgalactosaminidases (Nag31s) have been identified to hydrolyze the core of mucin-type O-glycans and the crystal structure of a gut bacterium Enterococcus faecalis Nag31 has been reported. However, the mechanisms of substrate specificity and hydrolysis of Nag31s are not well investigated. Herein, we show that E. faecalis Nag31 has the ability to release N-acetylgalactosamine (GalNAc) from O-glycoproteins, such as fetuin and mucin, but has low activity against Tn antigen. Mutational analysis and crystal structures of the Michaelis complexes reveal that residues of the active site work in concert with their conformational changes to act on only α-N-acetylgalactosaminides. Docking simulations using GalNAc-attached peptides suggest that the enzyme mainly recognizes GalNAc and side chains of Ser/Thr, but not strictly other peptide residues. Moreover, quantum mechanics calculations indicate that the enzyme preferred p-nitrophenyl α-N-acetylgalactosaminide to Tn antigen and that the hydrolysis progresses through a conformational itinerary, 4C1 → 1S3 → 4C1, in GalNAc of substrates. Our results provide novel insights into the diversification of the sugar recognition and hydrolytic mechanisms of GH31 enzymes.
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Affiliation(s)
- Takatsugu Miyazaki
- Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan; Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
| | - Marina Ikegaya
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Santiago Alonso-Gil
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Vienna, Austria.
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8
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Ikegaya M, Miyazaki T, Park EY. Biochemical characterization of Bombyx mori α-N-acetylgalactosaminidase belonging to the glycoside hydrolase family 31. INSECT MOLECULAR BIOLOGY 2021; 30:367-378. [PMID: 33742736 DOI: 10.1111/imb.12701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/22/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Horizontal gene transfer is an important evolutionary mechanism not only for bacteria but also for eukaryotes. In the domestic silkworm Bombyx mori, a model species of lepidopteran insects, some enzymes are known to have been acquired by horizontal transfer; however, the enzymatic features of protein BmNag31, belonging to glycoside hydrolase family 31 (GH31) and whose gene was predicted to be transferred from Enterococcus sp. are unknown. In this study, we reveal that the transcription of BmNag31 increases significantly during the prepupal to pupal stage, and decreases in the adult stage. The full-length BmNag31 and its truncated mutants were heterologously expressed in Escherichia coli and characterized. Its catalytic domain exhibits α-N-acetylgalactosaminidase activity and the carbohydrate-binding module family 32 domain shows binding activity towards N-acetylgalactosamine, similar to the Enterococcus faecalis homolog, EfNag31A. Gel filtration chromatography and blue native polyacrylamide gel electrophoresis analyses indicate that BmNag31 forms a hexamer whereas EfNag31A is monomeric. These results provide insights into the function of lepidopteran GH31 α-N-acetylgalactosaminidase.
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Affiliation(s)
- M Ikegaya
- Department of Agriculture, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, Japan
| | - T Miyazaki
- Department of Agriculture, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, Japan
- Green Chemistry Research Division, Research Institute of Green Science and Technology, Shizuoka University, Shizuoka, Japan
| | - E Y Park
- Department of Agriculture, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, Japan
- Green Chemistry Research Division, Research Institute of Green Science and Technology, Shizuoka University, Shizuoka, Japan
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Wu X, McFall-Boegeman H, Rashidijahanabad Z, Liu K, Pett C, Yu J, Schorlemer M, Ramadan S, Behren S, Westerlind U, Huang X. Synthesis and immunological evaluation of the unnatural β-linked mucin-1 Thomsen-Friedenreich conjugate. Org Biomol Chem 2021; 19:2448-2455. [PMID: 33645601 PMCID: PMC8011953 DOI: 10.1039/d1ob00007a] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
MUC1 glycopeptides are attractive antigens for anti-cancer vaccine development. One potential drawback in using the native MUC1 glycopeptide for vaccine design is the instability of the O-glycosyl linkage between the glycan and the peptide backbone to glycosidase. To overcome this challenge, a MUC1 glycopeptide mimic has been synthesized with the galactose-galactosamine disaccharide linked with threonine (Thomsen-Friedenreich or Tf antigen) through an unnatural β-glycosyl bond. The resulting MUC1-β-Tf had a much-enhanced stability toward a glycosidase capable of cleaving the glycan from the corresponding MUC1 glycopeptide with the natural α-Tf linkage. The MUC1-β-Tf was subsequently conjugated with a powerful carrier bacteriophage Qβ. The conjugate induced high levels of IgG antibodies in clinically relevant human MUC1 transgenic mice, which cross-recognized not only the natural MUC1-α-Tf glycopeptide but also MUC1 expressing tumor cells, supporting the notion that a simple switch of the stereochemistry of the glycan/peptide linkage can be a strategy for anti-cancer vaccine epitope design for glycopeptides.
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Affiliation(s)
- Xuanjun Wu
- National Glycoengineering Research Center, Shandong University, Qingdao, Shandong 266237, China
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