Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
The structure was elucidated in this paperNCBI PubMed ID: 31022484Publication DOI: 10.1016/j.ijbiomac.2019.04.143Journal NLM ID: 7909578Publisher: Butterworth-Heinemann
Correspondence: sqxu
jiangnan.edu.cn; chenjinghua
jiangnan.edu.cn
Institutions: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China, School of Pharmaceutical Science, Jiangnan University, Wuxi, China, Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
Polysaccharide K4 expressed from E. coli K4 has a similar structure with chondroitin, which can be used as a precursor to produce chondroitin sulfates. Here, we investigated the structure, conformation and biological activity of K4 from an engineered strain with high productivity. The NMR analysis suggested that K4 from wild-type strain with a low yield was a partially fructosylated chondroitin. While K4 from engineered strain was a fully fructosylated chondroitin. Light scattering analysis gave the Mw values of 6.15 x 104, 8.23 x 104 and 1.92 x 104 for K4-1, K4-2 and defructosylated K4 (DK4), respectively. The exponents of functions z1/2 = f(Mw) were in the range of 0.643-0.608, suggesting a random coil conformation for K4 and DK4. And the random coils K4 easily self-assembled into sphere-like aggregates in the dilute aqueous solution. Both K4 and DK4 exhibited significant immunomodulatory activities on RAW 264.7 cells at the dosage range of 5-500 microg/mL.
chemical structure, chondroitin, molecular weight, immunomodulatory activity, E.coli K4
Structure type: polymer chemical repeating unit ; 19200
Location inside paper: p.706, fig.2a, DK4
Trivial name: a fructosylated chondroitin
Compound class: CPS
Contained glycoepitopes: IEDB_115136,IEDB_130648,IEDB_137473,IEDB_140630,IEDB_153510,IEDB_423153
Methods: 13C NMR, 1H NMR, NMR-2D, ELISA, anion-exchange chromatography, FTIR, defructosylation, UV, statistical analysis, SEC, fermentation, cytokine production, dynamic light scattering, laser light scattering
Comments, role: An engineered E. coli K4 (E. coli K4-ΔpfkA-MglmM-glmS-L-galU-pgm-M-kfoC*, coded as ZQ25) (ATCC 23502); DK4 - defructosylated CPS
Related record ID(s): 1148
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G43702JT
Show glycosyltransferases
1H NMR data: present in publication
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13C NMR data: present in publication
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There is only one chemically distinct structure:
Found 
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