Controlled Photochemical Depolymerization of K5 Heparosan, a Bioengineered Heparin Precursor
Loading...
Authors
Higashi, Kyohei
Ly, Mellisa
Wang, Zhenyu
Masuko, Sayaka
Bhaskar, Ujjwal
Sterner, Eric
Zhang, Fuming
Toida, Toshihiko
Dordick, Jonathan S.
Linhardt, Robert J.
Issue Date
2011-08-30
Type
Article
Language
ENG
Keywords
Biology , Chemistry and chemical biology , Chemical and biological engineering , Biomedical engineering
Alternative Title
Abstract
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 1H-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.
Description
Carbohydrate Polymers, 86, 1365– 1370
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Note : if this item contains full text it may be a preprint, author manuscript, or a Gold OA copy that permits redistribution with a license such as CC BY. The final version is available through the publisher’s platform.
Full Citation
Controlled Photochemical Depolymerization of K5 Heparosan, a Bioengineered Heparin Precursor, K. Higashi, M. Ly, Z. Wang, S. Masuko, U. Bhaskar, E. Sterner, F. Zhang, T. Toida, J. S. Dordick, R. J. Linhardt, Carbohydrate Polymers, 86, 1365– 1370, 2011.
Publisher
Elsevier
Terms of Use
Journal
Volume
Issue
PubMed ID
DOI
ISSN
1448617