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Structure type: cyclic polymer repeating unit ; n=17-24
Trivial name: cyclosophoran, cyclic β-1,2-glucan, periplasmic cyclic β-1,2-glucan, cyclosophorans
Compound class: EPS
Contained glycoepitopes: IEDB_140628,IEDB_142488,IEDB_146664,IEDB_983931,SB_192

• Article ID: 327
  Mimura M, Kitamura S, Gotoh S, Takeo K, Urakawa H, Kajiwara K "Conformation of cyclic and linear (1->2)-b-D-glucans in aqueous solution" - Carbohydrate Research 289 (1996) 25-37
  

  The conformations of cyclic (1→2)-β-D-glucan chains having degree of polymerization (dp) 17 to 24 were characterized by means of small-angle X-ray scattering and Monte Carlo simulation. The results indicate that cyclic (1→2)-β-D-glucan chains adopt the shape of a doughnut-like ring with a thickness of about 10 A for all the samples. The diameter of the annulus for the cyclic glucan having dp 21 is estimated to be only about 4-5 A. Two linear (1→2)-β-D-glucans possessing dp 19 and 21 prepared by acid hydrolysis of a cyclic glucan and subsequent fractionation showed different scattering profiles from those obtained for cyclic glucans having the corresponding dp. Although the Monte Carlo simulation does not completely reproduce the scattering profiles observed by small-angle X-ray scattering, linear (1→2)-β-D-glucans seem to possess a characteristic cylindrical shape with cross-sectional diameters of 11.8 and 13.2 A for linear glucans of dp 19 and 21, respectively

  (1->2)-β-D-glucan, cyclic structure, small-angle X-ray scattering, Monte Carlo simulation

  NCBI PubMed ID: 8805774
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Institutions: Faculty of Engineering and Design, Kyoto Institute of Technology, Matsugasaki, Kyoto 606, Japan, Department of Agricultural Chemistry, Kyoto Prefectural University, Shimogamo, Kyoto 606, Japan
  Methods: 13C NMR, 1H NMR, X-ray, conformation analysis
  
   
  
  Agrobacterium radiobacter TFO 12607, Rhizobium phaseoli AHU 1133
  CSDB ID 7718 (all data & tools)
• Article ID: 3037
  Kinoshita S, Nakata M, Amemura A, Taguchi H "Purification of cyclic b-1,2-glucan synthetase from Agrobacterium radiobacter" - Journal of Fermentation and Bioengineering 72 (1991) 416-421
  

  A cyclic β-1,2-glucan synthetase was solubilized by sonicating 100,000 × g pellets of the crude extract of Agrobacterium radiobacter IFO 12665 A1-5 in the presence of ethylenediaminetetraacetic acid. The enzyme was separated by DEAE-Sephadex column chromatography into adsorbed and nonadsorbed fractions (cyclic β-1,2-glucan synthetases I and II, respectively). Both enzymes were further purified by Toyo-pearl HW55 gel filtration and high performance liquid chromatography on Shodex WS-803. Neither enzyme could penetrate into 4% polyacrylamide gel in sodium dodecyl sulfate polyacrylamide gel electrophoresis. The specific activity of synthetase I was 9.5 × 10−4 units/mg and it was purified 26-fold from the crude extract with a yield of 1.9%. Synthetase I was optimal at 33°C and pH 8-9 for the enzyme reaction. The activity was almost stable up to 40°C for 30 min, and mostly inactivated at 50°C for 30 min. The enzyme activity was stimulated about three times with the addition of 10-20 mM FeCl3. The enzyme produced the same cyclic β-1,2-glucan with a polymerization degree of 17-24 from UDP-glucose that the cell produced. The specific activity of synthetase II was 23.6 × 10−4 units/mg and it was purified 60-fold from the crude extract with a yield of 2.3%.

  Publication DOI: 10.1016/0922-338X(91)90047-K
  Journal NLM ID: 9000935
  Institutions: Department of Fermentation Technology, Faculty of Engineering, Osaka University, Yamadaoka, Suita-shi, Osaka 565, Japan
  
   
  
  Agrobacterium radiobacter IFO 12665 A1-5
  CSDB ID 139750 (all data & tools)
• Article ID: 3105
  Hisamatsu M "Cyclic (1 → 2)-β-D-glucans (cyclosophorans) produced by Agrobacterium and Rhizobium species" - Carbohydrate Research 231 (1992) 137-146
  

  Neutral and acidic cyclic (1→2)-β-D-glucans (cyclosophorans), obtained from culture filtrates and cells of Agrobacterium and Rhizobiun, are synthesised on the cell surface and then secreted. Eight cyclosophorans with dp 17-24 were isolated; all of the strains of Agrobacterium showed almost the same distribution pattern, whereas there were three other distribution patterns for the strains of Rhizobium.

  NCBI PubMed ID: 1394310
  Publication DOI: 10.1016/0008-6215(92)84014-j
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Institutions: Department of Agricultural Chemistry, Faculty of Bioresources, Mie University, Tsu, Japan
  
   
  
  Agrobacterium radiobacter, Agrobacterium rhizogenes, Rhizobium leguminosarum 303, Rhizobium lupini KLU, Rhizobium meliloti IFO 13337, Rhizobium meliloti J7017, Rhizobium phaseoli AHU 1133, Rhizobium trifolii IFO 13337, Rhizobium trifolii 4S, Rhizobium trifolii AHU 1134
  CSDB ID 116769 (all data & tools)
• Article ID: 3857
  Haag AF, Myka KK, Arnold MF, Caro-Hernandez P, Ferguson GP "Importance of Lipopolysaccharide and Cyclic b-1,2-Glucans in Brucella-Mammalian Infections" - International Journal of Microbiology 201 (2010) 124509
  

  Brucella species are the causative agents of one of the most prevalent zoonotic diseases: brucellosis. Infections by Brucella species cause major economic losses in agriculture, leading to abortions in infected animals and resulting in a severe, although rarely lethal, debilitating disease in humans. Brucella species persist as intracellular pathogens that manage to effectively evade recognition by the host's immune system. Sugar-modified components in the Brucella cell envelope play an important role in their host interaction. Brucella lipopolysaccharide (LPS), unlike Escherichia coli LPS, does not trigger the host's innate immune system. Brucella produces cyclic β-1,2-glucans, which are important for targeting them to their replicative niche in the endoplasmic reticulum within the host cell. This paper will focus on the role of LPS and cyclic β-1,2-glucans in Brucella-mammalian infections and discuss the use of mutants, within the biosynthesis pathway of these cell envelope structures, in vaccine development

  biosynthesis, cell envelope, Brucella-mammalian infections

  NCBI PubMed ID: 21151694
  Journal NLM ID: 101516125
  Publisher: Hindawi Publishing Corporation
  Correspondence: g.ferguson@abdn.ac.uk
  Institutions: School of Medicine & Dentistry, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
  
   
  
  Brucella
  CSDB ID 25270 (all data & tools)
• Article ID: 4001
  Choma A, Komaniecka I "Characterization of cyclic b-glucans of Bradyrhizobium by MALDI-TOF mass spectrometry" - Carbohydrate Research 346(13) (2011) 1945-1950
  

  Periplasmic, cyclic β-glucans isolated from Bradyrhizobium elkanii, Bradyrhizobium liaoningense, and Bradyrhizobium yuanmingense strains have been investigated by means of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), 1D and 2D nuclear magnetic resonance (NMR), as well as standard chemical methods. These compounds are built of 10-13 d-glucose residues. The main fractions contain molecules assembled of 12 hexose units (M(w)=1945.363Da). Glucose monomers are linked by β-(1→3) or β-(1→6) glycosidic bonds. The ratio of β-(1→3) to β-(1→6) linked glucose is approximately 1:2. Moreover, methylation analysis demonstrated the presence of terminal, non-reducing, as well as branched (i.e., 3- and 6-substituted) glucoses. Thus, the basic structure of the investigated compounds is similar to that of periplasmic oligosaccharides from Bradyrhizobium japonicum and Azorhizobium caulinodans strains. The analyzed cyclic β-glucans are substituted by phosphocholine (PC) (one or two residues per ring) and highly decorated with acetate and succinate. The substituents are arranged diversely in the population of cyclic β-glucan molecules. The concentrations of cyclic β-glucans in Bradyrhizobium periplasmic space are osmotically regulated and increase in response to a decrease of medium osmolarity.

  MALDI-TOF, Bradyrhizobium, cyclic-b-glucan, osmoregulation, Phosphocholinyl and succinyl substituents

  NCBI PubMed ID: 21665197
  Publication DOI: 10.1016/j.carres.2011.05.015
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: A. Choma ; achoma@hektor.umcs.lublin.pl
  Institutions: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, 19 Akademicka St., 20-033 Lublin, Poland
  Methods: 13C NMR, 1H NMR, methylation, NMR-2D, GC-MS, HF solvolysis, de-O-acylation, MALDI-TOF MS, composition analysis, NMR-1D
  
   
  
  Rhizobium meliloti
  CSDB ID 26164 (all data & tools)
• Article ID: 4966
  Xu L, Zhang J "Bacterial glucans: production, properties, and applications" - Applied Microbiology and Biotechnology 100(21) (2016) 9023-9036
  

  Bacterial glucans have aroused increasing interest in commercial applications in the food and pharmaceutical sectors. A number of bacterial glucans have been reported over recent decades, and their structure, production, and functional properties have been extensively studied. In this paper, we review recent researches on bacterial glucans, with emphasis on the production, physical and chemical properties, and the new developments in food, biomedical, pharmaceutical, and other industrial applications.

  food, property, production, pharmaceutical, Bacterial glucans, Biomedical

  NCBI PubMed ID: 27678120
  Publication DOI: 10.1007/s00253-016-7836-6
  Journal NLM ID: 8406612
  Publisher: Springer
  Correspondence: jfzhang@mail.njust.edu.cn
  Institutions: Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing, 210094, China
  
   
  
  Agrobacterium, Rhizobium, Xanthomonas
  CSDB ID 11829 (all data & tools)