Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
The structure was elucidated in this paperNCBI PubMed ID: 21841848Publication DOI: 10.1016/j.carbpol.2011.06.042Journal NLM ID: 8307156Publisher: Elsevier
Institutions: Graduate School of Pharmaceutical Sciences Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
Heparosan is a polysaccharide, which serves as the critical precursor in heparin biosynthesis and chemoenzymatic synthesis of bioengineered heparin. Because the molecular weight of microbial heparosan is considerably larger than heparin, the controlled depolymerization of microbial heparosan is necessary prior to its conversion to bioengineered heparin. We have previously reported that other acidic polysaccharides could be partially depolymerized with maintenance of their internal structure using a titanium dioxide-catalyzed photochemical reaction. This photolytic process is characterized by the generation of reactive oxygen species that oxidize individual saccharide residues within the polysaccharide chain. Using a similar approach, a microbial heparosan from Escherichia coli K5 of molecular weight >15,000 was depolymerized to a heparosan of molecular weight 8,000. The (1)H-NMR spectra obtained showed that the photolyzed heparosan maintained the same structure as the starting heparosan. The polysaccharide chains of the photochemically depolymerized heparosan were also characterized by electrospray ionization-Fourier-transform mass spectrometry. While the chain of K5 heparosan starting material contained primarily an even number of saccharide residues, as a result of coliphage K5 lyase processing, both odd and even chain numbers were detected in the photochemically-depolymerized heparosan. These results suggest that the photochemical depolymerization of heparosan was a random process that can take place at either the glucuronic acid or the N-acetylglucosamine residue within the heparosan polysaccharide.
heparin, depolymerization, Heparosan, photochemical, titanium dioxide
Structure type: polymer chemical repeating unit ; 15000
Location inside paper: p.1367, fig.1, p.1369
Trivial name: heparosan
Compound class: CPS
Contained glycoepitopes: IEDB_115136,IEDB_140630,IEDB_141807,IEDB_151531,IEDB_153764,IEDB_423153
Methods: 1H NMR, ESI-FT-MS, HPLC, GPC, PAGE, photolytic depolymerization
NCBI Taxonomy refs (TaxIDs): 562Reference(s) to other database(s): GTC:G26089XS
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There is only one chemically distinct structure:
Found 
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