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Abstract
Glycans, carbohydrate molecules in the realm of biology, are present as biomedically important glycoconjugates and a characteristic aspect is that their structures in many instances are branched. In determining the primary structure of a glycan, the sugar components including the absolute configuration and ring form, anomeric configuration, linkage(s), sequence, and substituents should be elucidated. Solution state NMR spectroscopy offers a unique opportunity to resolve all these aspects at atomic resolution. During the last two decades, advancement of both NMR experiments and spectrometer hardware have made it possible to unravel carbohydrate structure more efficiently. These developments applicable to glycans include, inter alia, NMR experiments that reduce spectral overlap, use selective excitations, record tilted projections of multidimensional spectra, acquire spectra by multiple receivers, utilize polarization by fast-pulsing techniques, concatenate pulse-sequence modules to acquire several spectra in a single measurement, acquire pure shift correlated spectra devoid of scalar couplings, employ stable isotope labeling to efficiently obtain homo- and/or heteronuclear correlations, as well as those that rely on dipolar cross-correlated interactions for sequential information. Refined computer programs for NMR spin simulation and chemical shift prediction aid the structural elucidation of glycans, which are notorious for their limited spectral dispersion. Hardware developments include cryogenically cold probes and dynamic nuclear polarization techniques, both resulting in enhanced sensitivity as well as ultrahigh field NMR spectrometers with a 1H NMR resonance frequency higher than 1 GHz, thus improving resolution of resonances. Taken together, the developments have made and will in the future make it possible to elucidate carbohydrate structure in great detail, thereby forming the basis for understanding of how glycans interact with other molecules.
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Affiliation(s)
- Carolina Fontana
- Departamento
de Química del Litoral, CENUR Litoral Norte, Universidad de la República, Paysandú 60000, Uruguay
| | - Göran Widmalm
- Department
of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden,
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Zhu YM, Pan LC, Zhang LJ, Yin Y, Zhu ZY, Sun HQ, Liu CY. Chemical structure and antioxidant activity of a polysaccharide from Siraitia grosvenorii. Int J Biol Macromol 2020; 165:1900-1910. [PMID: 33096178 DOI: 10.1016/j.ijbiomac.2020.10.127] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 09/22/2020] [Accepted: 10/14/2020] [Indexed: 11/28/2022]
Abstract
A novel polysaccharide from Siraitia grosvenorii residues (SGP, molecular weight 1.93 × 103 KDa) was isolated and purified. SGP was composed of α-L-Arabinose, α-D-Mannose, α-d-Glucose, α-D-Galactose, Glucuronic acid, and Galacturonic acid with the ratio of 1: 1.92: 3.98: 7.63: 1.85: 7.34. The backbone of SGP was consist of galactoses and linked by α-(1,4)-glycosidic bond. The branch chains including α-1,6 linked glucose branch, α-1,6 linked mannose branch, α-1,3 linked galactose branch and arabinose branched (α-L-Ara(1→). The results of bioactivity experiments suggested that SGP had antioxidant in vitro, especially on scavenging DPPH radicals. Besides, SGP resulted in the decrease of ROS and the percentage of apoptotic and necrotic cells in a dose-dependent manner in H2O2 oxide injury PC12 cells. This research could help to develop the potential value and utilization of Siraitia grosvenorii.
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Affiliation(s)
- Yong-Ming Zhu
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Li-Chao Pan
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Li-Juan Zhang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Yue Yin
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Zhen-Yuan Zhu
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China.
| | - Hui-Qing Sun
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Chun-Yu Liu
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, PR China; Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, PR China; College of Food Science and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
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Liu B, Furevi A, Perepelov AV, Guo X, Cao H, Wang Q, Reeves PR, Knirel YA, Wang L, Widmalm G. Structure and genetics of Escherichia coli O antigens. FEMS Microbiol Rev 2020; 44:655-683. [PMID: 31778182 PMCID: PMC7685785 DOI: 10.1093/femsre/fuz028] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 11/22/2019] [Indexed: 02/07/2023] Open
Abstract
Escherichia coli includes clonal groups of both commensal and pathogenic strains, with some of the latter causing serious infectious diseases. O antigen variation is current standard in defining strains for taxonomy and epidemiology, providing the basis for many serotyping schemes for Gram-negative bacteria. This review covers the diversity in E. coli O antigen structures and gene clusters, and the genetic basis for the structural diversity. Of the 187 formally defined O antigens, six (O31, O47, O67, O72, O94 and O122) have since been removed and three (O34, O89 and O144) strains do not produce any O antigen. Therefore, structures are presented for 176 of the 181 E. coli O antigens, some of which include subgroups. Most (93%) of these O antigens are synthesized via the Wzx/Wzy pathway, 11 via the ABC transporter pathway, with O20, O57 and O60 still uncharacterized due to failure to find their O antigen gene clusters. Biosynthetic pathways are given for 38 of the 49 sugars found in E. coli O antigens, and several pairs or groups of the E. coli antigens that have related structures show close relationships of the O antigen gene clusters within clades, thereby highlighting the genetic basis of the evolution of diversity.
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Affiliation(s)
- Bin Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjing 300457, China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Axel Furevi
- Department of Organic Chemistry, Arrhenius Laboratory, Svante Arrhenius väg 16C, Stockholm University, S-106 91 Stockholm, Sweden
| | - Andrei V Perepelov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, Moscow, Russia
| | - Xi Guo
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjing 300457, China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Hengchun Cao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjing 300457, China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Quan Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjing 300457, China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Peter R Reeves
- School of Molecular and Microbial Bioscience, University of Sydney, 2 Butilin Ave, Darlington NSW 2008, Sydney, Australia
| | - Yuriy A Knirel
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect, 47, Moscow, Russia
| | - Lei Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjing 300457, China
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Göran Widmalm
- Department of Organic Chemistry, Arrhenius Laboratory, Svante Arrhenius väg 16C, Stockholm University, S-106 91 Stockholm, Sweden
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