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Li CC, Yi H, Wang YM, Tang XY, Zhu YB, Song YJ, Zhao NL, Huang Q, Mou XY, Luo GH, Liu TG, Yang GL, Zeng YJ, Wang LJ, Tang H, Fan G, Bao R. Nucleotide binding as an allosteric regulatory mechanism for Akkermansia muciniphila β- N-acetylhexosaminidase Am2136. Gut Microbes 2022; 14:2143221. [PMID: 36394293 PMCID: PMC9673926 DOI: 10.1080/19490976.2022.2143221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
β-N-acetylhexosaminidases (EC3.2.1.52), which belong to the glycosyl hydrolase family GH20, are important enzymes for oligosaccharides modification. Numerous microbial β-N-acetylhexosaminidases have been investigated for applications in biology, biomedicine and biotechnology. Akkermansia muciniphila is an anaerobic intestinal commensal bacterium which possesses specific β-N-acetylhexosaminidases for gut mucosal layer colonization and mucin degradation. In this study, we assessed the in vitro mucin glycan cleavage activity of the A. muciniphila β-N-acetylhexosaminidase Am2136 and demonstrated its ability that hydrolyzing the β-linkages joining N-acetylglucosamine to a wide variety of aglycone residues, which indicated that Am2136 may be a generalist β-N-acetylhexosaminidase. Structural and enzyme activity assay experiments allowed us to probe the essential function of the inter-domain interactions in β23-β33. Importantly, we revealed that the hydrolysis activity of Am2136 was enhanced by nucleotides. We further speculated that this activation mechanism might be associated with the conformational motions between domain III and IV. To our knowledge, this is the first report of nucleotide effector regulated β-N-acetylhexosaminidase, to reveal its novel biological functions. These findings contribute to understanding the distinct properties within the GH20 family and lay a certain foundation to develop controllable glycan hydrolyzing catalysts.Abbreviations: OD600 - optical cell densities at 600 nm; LB - Luria-Bertani; IPTG - isopropyl β-D-1-thiogalactopyranoside; PMSF - phenylmethanesulfonyl fluoride; rmsd - root mean square deviation; GlcNAc - N-acetyl-β-D-glucosamine; GalNAc - N-acetyl-β-D-galactosamine; Gal - galactose.
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Affiliation(s)
- Chang-Cheng Li
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Huan Yi
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yan-Mei Wang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu, China
| | - Xin-Yue Tang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Yi-Bo Zhu
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Ying-Jie Song
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Ning-Lin Zhao
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Qin Huang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Xing-Yu Mou
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Gui-Hua Luo
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Tong-Gen Liu
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China
| | - Gang-Long Yang
- School of Biotechnology, Jiangnan University, Chengdu, China
| | - Yu-Jiao Zeng
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Li-Jie Wang
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hong Tang
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China,Hong Tang Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University. Chengdu. China
| | - Gang Fan
- State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China,Gang Fan State Key Laboratory of Southwestern Chinese Medicine Resources, College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine. Chengdu. China
| | - Rui Bao
- Division of Infectious Diseases, State Key Laboratory of Biotherapy and Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, China,CONTACT Rui Bao
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Nekvasilová P, Kulik N, Kotik M, Petrásková L, Slámová K, Křen V, Bojarová P. Mutation Hotspot for Changing the Substrate Specificity of β- N-Acetylhexosaminidase: A Library of GlcNAcases. Int J Mol Sci 2022; 23:12456. [PMID: 36293310 PMCID: PMC9604439 DOI: 10.3390/ijms232012456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/27/2022] [Accepted: 10/12/2022] [Indexed: 12/27/2023] Open
Abstract
β-N-Acetylhexosaminidase from Talaromyces flavus (TfHex; EC 3.2.1.52) is an exo-glycosidase with dual activity for cleaving N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) units from carbohydrates. By targeting a mutation hotspot of the active site residue Glu332, we prepared a library of ten mutant variants with their substrate specificity significantly shifted towards GlcNAcase activity. Suitable mutations were identified by in silico methods. We optimized a microtiter plate screening method in the yeast Pichia pastoris expression system, which is required for the correct folding of tetrameric fungal β-N-acetylhexosaminidases. While the wild-type TfHex is promiscuous with its GalNAcase/GlcNAcase activity ratio of 1.2, the best single mutant variant Glu332His featured an 8-fold increase in selectivity toward GlcNAc compared with the wild-type. Several prepared variants, in particular Glu332Thr TfHex, had significantly stronger transglycosylation capabilities than the wild-type, affording longer chitooligomers - they behaved like transglycosidases. This study demonstrates the potential of mutagenesis to alter the substrate specificity of glycosidases.
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Affiliation(s)
- Pavlína Nekvasilová
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, CZ-12843 Praha 2, Czech Republic
| | - Natalia Kulik
- Laboratory of Structural Biology and Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Zámek 136, CZ-37333 Nové Hrady, Czech Republic
| | - Michael Kotik
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
| | - Lucie Petrásková
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
| | - Kristýna Slámová
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
| | - Vladimír Křen
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
| | - Pavla Bojarová
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-14220 Praha 4, Czech Republic
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Kurakake M, Amai Y. Characterization of a β-N-acetylhexosaminidase with transglycosylation activity from Metarhizium sp. A34. J Food Sci 2022; 87:1466-1474. [PMID: 35289418 DOI: 10.1111/1750-3841.16113] [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: 10/23/2021] [Revised: 02/08/2022] [Accepted: 02/15/2022] [Indexed: 11/27/2022]
Abstract
In applications of chitin, one of the most abundant resources on earth, human milk oligosaccharides with many health functions were synthesized by transglycosylation of β-N-acetylhexosaminidase. Synthesis of new transfer products can be expected by other β-N-acetylhexosaminidases in nature. A total of 38 microorganisms that secrete β-N-acetylhexosaminidases with transglycosylation activity were isolated from a soil screen. Using N,N'-diacetylchitobiose as the substrate, the transfer ratio increased with a decrease in substrate degradation when it was less than 60%. Metarhizium sp. A34 β-N-acetylhexosaminidase had high transglycosylation activity and showed a maximum production of the oligosaccharides against the substrate degradation where (GlcNAc)5 and (GlcNAc)4 were produced in addition to (GlcNAc)3 . The maximum curve was attributed to a sequential reaction of transglycosylation followed by hydrolysis where oligosaccharides are an intermediate product and are hydrolyzed in a second step. The purified β-N-acetylhexosaminidase from Metarhizium sp. A34 had an optimal pH of 5 and was stable from pH 7 to 8. At pH 5, it had an optimal temperature of 40°C and was stable up to 30°C for 30 min. This enzyme had high thermostability up to 55°C when bound to the cell wall. The acceptor specificity for the transglycosylation reaction was enhanced for lower molecular weight sugar alcohols in the order of glycerin (C3), erythritol (C4), and xylitol (C5). The transfer product with glycerin was identified as 1-O-β-d-N-acetylglucosaminyl glycerin, which may prove useful as a starting material for new glycolipids in food applications. PRACTICAL APPLICATION: Metarhizium sp. A34 β-N-acetylhexosaminidase produced 1-O-β-d-N-acetylglucosaminyl glycerin through the transglycosylation. Chitin oligosaccharides of the donor are obtained by hydrolysis of chitin. 1-O-β-d-N-Acetylglucosaminyl glycerin may be useful to start material for the synthesis of new glycolipids. High thermostability of this enzyme is useful to prevention of contamination in the transglycosylation reaction.
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Affiliation(s)
- Masahiro Kurakake
- Department of Marine Bio-Science, Fukuyama University, Fukuyama, Japan
| | - Yukari Amai
- Department of Marine Bio-Science, Fukuyama University, Fukuyama, Japan
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Zhang A, Mo X, Zhou N, Wang Y, Wei G, Chen J, Chen K, Ouyang P. A novel bacterial β- N-acetyl glucosaminidase from Chitinolyticbacter meiyuanensis possessing transglycosylation and reverse hydrolysis activities. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:115. [PMID: 32612678 PMCID: PMC7324980 DOI: 10.1186/s13068-020-01754-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/20/2020] [Indexed: 05/31/2023]
Abstract
BACKGROUND N-Acetyl glucosamine (GlcNAc) and N-Acetyl chitooligosaccharides (N-Acetyl COSs) exhibit many biological activities, and have been widely used in the pharmaceutical, agriculture, food, and chemical industries. Particularly, higher N-Acetyl COSs with degree of polymerization from 4 to 7 ((GlcNAc)4-(GlcNAc)7) show good antitumor and antimicrobial activity, as well as possessing strong stimulating activity toward natural killer cells. Thus, it is of great significance to discover a β-N-acetyl glucosaminidase (NAGase) that can not only produce GlcNAc, but also synthesize N-Acetyl COSs. RESULTS The gene encoding the novel β-N-acetyl glucosaminidase, designated CmNAGase, was cloned from Chitinolyticbacter meiyuanensis SYBC-H1. The deduced amino acid sequence of CmNAGase contains a glycoside hydrolase family 20 catalytic module that shows low identity (12-35%) with the corresponding domain of most well-characterized NAGases. The CmNAGase gene was highly expressed with an active form in Escherichia coli BL21 (DE3) cells. The specific activity of purified CmNAGase toward p-nitrophenyl-N-acetyl glucosaminide (pNP-GlcNAc) was 4878.6 U/mg of protein. CmNAGase had a molecular mass of 92 kDa, and its optimum activity was at pH 5.4 and 40 °C. The V max, K m, K cat, and K cat/K m of CmNAGase for pNP-GlcNAc were 16,666.67 μmol min-1 mg-1, 0.50 μmol mL-1, 25,555.56 s-1, and 51,111.12 mL μmol-1 s-1, respectively. Analysis of the hydrolysis products of N-Acetyl COSs and colloidal chitin revealed that CmNAGase is a typical exo-acting NAGase. Particularly, CmNAGase can synthesize higher N-Acetyl COSs ((GlcNAc)3-(GlcNAc)7) from (GlcNAc)2-(GlcNAc)6, respectively, showed that it possesses transglycosylation activity. In addition, CmNAGase also has reverse hydrolysis activity toward GlcNAc, synthesizing various linked GlcNAc dimers. CONCLUSIONS The observations recorded in this study that CmNAGase is a novel NAGase with exo-acting, transglycosylation, and reverse hydrolysis activities, suggest a possible application in the production of GlcNAc or higher N-Acetyl COSs.
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Affiliation(s)
- Alei Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Xiaofang Mo
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Ning Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Yingying Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Guoguang Wei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Jie Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Kequan Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
| | - Pingkai Ouyang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800 People’s Republic of China
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Abstract
β-N-acetylhexosaminidases (EC 3.2.1.52) are retaining hydrolases of glycoside hydrolase family 20 (GH20). These enzymes catalyze hydrolysis of terminal, non-reducing N-acetylhexosamine residues, notably N-acetylglucosamine or N-acetylgalactosamine, in N-acetyl-β-D-hexosaminides. In nature, bacterial β-N-acetylhexosaminidases are mainly involved in cell wall peptidoglycan synthesis, analogously, fungal β-N-acetylhexosaminidases act on cell wall chitin. The enzymes work via a distinct substrate-assisted mechanism that utilizes the 2-acetamido group as nucleophile. Curiously, the β-N-acetylhexosaminidases possess an inherent trans-glycosylation ability which is potentially useful for biocatalytic synthesis of functional carbohydrates, including biomimetic synthesis of human milk oligosaccharides and other glycan-functionalized compounds. In this review, we summarize the reaction engineering approaches (donor substrate activation, additives, and reaction conditions) that have proven useful for enhancing trans-glycosylation activity of GH20 β-N-acetylhexosaminidases. We provide comprehensive overviews of reported synthesis reactions with GH20 enzymes, including tables that list the specific enzyme used, donor and acceptor substrates, reaction conditions, and details of the products and yields obtained. We also describe the active site traits and mutations that appear to favor trans-glycosylation activity of GH20 β-N-acetylhexosaminidases. Finally, we discuss novel protein engineering strategies and suggest potential “hotspots” for mutations to promote trans-glycosylation activity in GH20 for efficient synthesis of specific functional carbohydrates and other glyco-engineered products.
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Identification and Characterization of a β- N-Acetylhexosaminidase with a Biosynthetic Activity from the Marine Bacterium Paraglaciecola hydrolytica S66 T. Int J Mol Sci 2020; 21:ijms21020417. [PMID: 31936522 PMCID: PMC7014002 DOI: 10.3390/ijms21020417] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/04/2020] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
β-N-Acetylhexosaminidases are glycoside hydrolases (GHs) acting on N-acetylated carbohydrates and glycoproteins with the release of N-acetylhexosamines. Members of the family GH20 have been reported to catalyze the transfer of N-acetylglucosamine (GlcNAc) to an acceptor, i.e., the reverse of hydrolysis, thus representing an alternative to chemical oligosaccharide synthesis. Two putative GH20 β-N-acetylhexosaminidases, PhNah20A and PhNah20B, encoded by the marine bacterium Paraglaciecola hydrolytica S66T, are distantly related to previously characterized enzymes. Remarkably, PhNah20A was located by phylogenetic analysis outside clusters of other studied β-N-acetylhexosaminidases, in a unique position between bacterial and eukaryotic enzymes. We successfully produced recombinant PhNah20A showing optimum activity at pH 6.0 and 50 °C, hydrolysis of GlcNAc β-1,4 and β-1,3 linkages in chitobiose (GlcNAc)2 and GlcNAc-1,3-β-Gal-1,4-β-Glc (LNT2), a human milk oligosaccharide core structure. The kinetic parameters of PhNah20A for p-nitrophenyl-GlcNAc and p-nitrophenyl-GalNAc were highly similar: kcat/KM being 341 and 344 mM−1·s−1, respectively. PhNah20A was unstable in dilute solution, but retained full activity in the presence of 0.5% bovine serum albumin (BSA). PhNah20A catalyzed the formation of LNT2, the non-reducing trisaccharide β-Gal-1,4-β-Glc-1,1-β-GlcNAc, and in low amounts the β-1,2- or β-1,3-linked trisaccharide β-Gal-1,4(β-GlcNAc)-1,x-Glc by a transglycosylation of lactose using 2-methyl-(1,2-dideoxy-α-d-glucopyrano)-oxazoline (NAG-oxazoline) as the donor. PhNah20A is the first characterized member of a distinct subgroup within GH20 β-N-acetylhexosaminidases.
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Chen X, Jin L, Jiang X, Guo L, Gu G, Xu L, Lu L, Wang F, Xiao M. Converting a β-N-acetylhexosaminidase into two trans-β-N-acetylhexosaminidases by domain-targeted mutagenesis. Appl Microbiol Biotechnol 2019; 104:661-673. [PMID: 31822984 DOI: 10.1007/s00253-019-10253-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/29/2019] [Accepted: 11/12/2019] [Indexed: 01/14/2023]
Abstract
We have recently derived a β-N-acetylhexosaminidase, BbhI, from Bifidobacterium bifidum JCM 1254, which could regioselectively synthesize GlcNAcβ1-3Galβ1-4Glc with a yield of 44.9%. Here, directed evolution of BbhI by domain-targeted mutagenesis was carried out. Firstly, the GH20 domain was selected for random mutagenesis using MEGAWHOP method and a small library of 1300 clones was created. A total of 734 colonies with reduced hydrolytic activity were isolated, and three mutants with elevated transglycosylation yields, GlcNAcβ1-3Galβ1-4Glc yields of 68.5%, 74.7%, and 81.1%, respectively, were obtained. Subsequently, nineteen independent mutants were constructed according to all the mutation sites in these three mutants. After transglycosylation analysis, Asp714 and Trp773 were identified as key residues for improvement in transglycosylation ability and were chosen for the second round of directed evolution by site-saturation mutagenesis. Two most efficient mutants D714T and W773R that acted as trans-β-N-acetylhexosaminidase were finally achieved. D714T with the substitution at the putative nucleophile assistant residue Asp714 by threonine showed high yield of 84.7% with unobserved hydrolysis towards transglycosylation product. W773R with arginine substitution at Trp773 residue locating at the entrance of catalytic cavity led to the yield up to 81.8%. The kcat/Km values of D714T and W773R for hydrolysis of pNP-β-GlcNAc displayed drastic decreases. NMR investigation of protein-substrate interaction revealed an invariable mode of the catalytic cavity of D714T, W773R, and WT BbhI. The collective motions of protein model showed the mutations Thr714 and Arg773 exerted little effect on the dynamics of the inside but a large effect on the dynamics of the outside of catalytic cavity.
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Affiliation(s)
- Xiaodi Chen
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China.,School of Pharmaceutical Sciences, Shandong University, Jinan, 250012, People's Republic of China
| | - Lan Jin
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Xukai Jiang
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Longcheng Guo
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Guofeng Gu
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Li Xu
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China
| | - Lili Lu
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | - Fengshan Wang
- School of Pharmaceutical Sciences, Shandong University, Jinan, 250012, People's Republic of China
| | - Min Xiao
- State Key Lab of Microbial Technology, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao, 266237, People's Republic of China.
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Kurakake M, Amai Y, Konishi M, Ikehira K. Characteristics of an β-N-Acetylhexosaminidase from Bacillus sp. CH11, Including its Transglycosylation Activity. J Food Sci 2018; 83:1208-1214. [PMID: 29624688 DOI: 10.1111/1750-3841.14125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 01/29/2018] [Accepted: 02/23/2018] [Indexed: 11/27/2022]
Abstract
β-N-Acetylhexosaminidase was identified from Bacillus sp. CH11 and found to have relatively high transferring activity. In this study, its enzymatic properties and transglycosylation activity including its acceptor specificity were investigated. Its molecular weight was estimated to be 90 kDa by SDS-PAGE and its optimal pH was approximately 7 with good stability from pH 6 to 8. Its optimal temperature was 40 °C, and its activity was stable at temperatures of up to 40 °C. To analyze its acceptor specificity for transglycosylation, N, N'-diacetylchitobiose was used as a donor substrate and alcohols, sugar alcohols, sugars and polyphenols were used as acceptors. Dialcohols, which have 2 hydroxyl groups on the outside of the carbon chains, were good acceptors. The molecular size of the acceptor did not influence the transglycosylation up to at least 1,5-pentanediol (carbon number: C5). Glycerin (C3), erythritol (C4), and xylitol (C5), all small molecular weight sugar alcohols, had high acceptor specificity. Transglycosylation to mono- and disaccharides and polyphenols was not observed except for L-fucose. For the β-N-acetylhexosaminidase-catalyzed transglycosylation of chitin oligosaccharides and xylitol, the transfer product was identified as 1-O-β-D-N-acetylglucosaminyl xylitol. The optimal ratio of xylitol was 24% to 2% N, N'-diacetylchitobiose and 226 mg per 1 g N, N'-diacetylchitobiose was produced. CH11 β-N-acetylhexosaminidase efficiently produced 1-O-β-D-N-acetylglucosaminyl xylitol via transglycosylation. PRACTICAL APPLICATION The new transfer products including 1-O-β-D-N-acetylglucosaminyl xylitol are attractive compounds for their potential physiological functions. 1-O-β-D-N-Acetylglucosaminyl xylitol was produced effectively from chitin-oligosaccharides and xylitol by β-N-acetylhexosaminidase from Bacillus sp. CH11. This enzyme may be useful for the development of food materials for health-related applications such as oligosaccharides with intestinal functions and noncariogenic sugars.
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Affiliation(s)
- Masahiro Kurakake
- Dept. of Marine Biotechnology, Fukuyama Univ., 1-985 Sanzo, Higashimura-cho, Fukuyama, Hiroshima 729-0292, Japan
| | - Yukari Amai
- Dept. of Marine Biotechnology, Fukuyama Univ., 1-985 Sanzo, Higashimura-cho, Fukuyama, Hiroshima 729-0292, Japan
| | - Mizuki Konishi
- Dept. of Marine Biotechnology, Fukuyama Univ., 1-985 Sanzo, Higashimura-cho, Fukuyama, Hiroshima 729-0292, Japan
| | - Kaho Ikehira
- Dept. of Marine Biotechnology, Fukuyama Univ., 1-985 Sanzo, Higashimura-cho, Fukuyama, Hiroshima 729-0292, Japan
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Efficient and Regioselective Synthesis of β-GalNAc/GlcNAc-Lactose by a Bifunctional Transglycosylating β-N-Acetylhexosaminidase from Bifidobacterium bifidum. Appl Environ Microbiol 2016; 82:5642-52. [PMID: 27422836 DOI: 10.1128/aem.01325-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/29/2016] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED β-N-Acetylhexosaminidases have attracted interest particularly for oligosaccharide synthesis, but their use remains limited by the rarity of enzyme sources , low efficiency, and relaxed regioselectivity of transglycosylation. In this work, genes of 13 β-N-acetylhexosaminidases, including 5 from Bacteroides fragilis ATCC 25285, 5 from Clostridium perfringens ATCC 13124, and 3 from Bifidobacterium bifidum JCM 1254, were cloned and heterogeneously expressed in Escherichia coli The resulting recombinant enzymes were purified and screened for transglycosylation activity. A β-N-acetylhexosaminidase named BbhI, which belongs to glycoside hydrolase family 20 and was obtained from B. bifidum JCM 1254, possesses the bifunctional property of efficiently transferring both GalNAc and GlcNAc residues through β1-3 linkage to the Gal residue of lactose. The effects of initial substrate concentration, pH, temperature, and reaction time on transglycosylation activities of BbhI were studied in detail. With the use of 10 mM pNP-β-GalNAc or 20 mM pNP-β-GlcNAc as the donor and 400 mM lactose as the acceptor in phosphate buffer (pH 5.8), BbhI synthesized GalNAcβ1-3Galβ1-4Glc and GlcNAcβ1-3Galβ1-4Glc at maximal yields of 55.4% at 45°C and 4 h and 44.9% at 55°C and 1.5 h, respectively. The model docking of BbhI with lactose showed the possible molecular basis of strict regioselectivity of β1-3 linkage in β-N-acetylhexosaminyl lactose synthesis. IMPORTANCE Oligosaccharides play a crucial role in many biological events and therefore are promising potential therapeutic agents. However, their use is limited because large-scale production of oligosaccharides is difficult. The chemical synthesis requires multiple protecting group manipulations to control the regio- and stereoselectivity of glycosidic bonds. In comparison, enzymatic synthesis can produce oligosaccharides in one step by using glycosyltransferases and glycosidases. Given the lower price of their glycosyl donor and their broader acceptor specificity, glycosidases are more advantageous than glycosyltransferases for large-scale synthesis. β-N-Acetylhexosaminidases have attracted interest particularly for β-N-acetylhexosaminyl oligosaccharide synthesis, but their application is affected by having few enzyme sources, low efficiency, and relaxed regioselectivity of transglycosylation. In this work, we describe a microbial β-N-acetylhexosaminidase that exhibited strong transglycosylation activity and strict regioselectivity for β-N-acetylhexosaminyl lactose synthesis and thus provides a powerful synthetic tool to obtain biologically important GalNAcβ1-3Lac and GlcNAcβ1-3Lac.
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Slámová K, Bojarová P, Petrásková L, Křen V. β-N-Acetylhexosaminidase: What's in a name…? Biotechnol Adv 2010; 28:682-93. [DOI: 10.1016/j.biotechadv.2010.04.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 04/17/2010] [Accepted: 04/24/2010] [Indexed: 01/28/2023]
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