Heparan biosynthesis

Some of the polysaccharides constituting intermediate stages in the biosynthesis of heparin have been physically isolated.23 Their structure is strikingly similar to those of heparan sulfates,24 thus re-opening the often-raised question as to whether heparan sulfate indeed represents products of incomplete biosynthesis of heparin. A detailed account of the structure and biological properties of heparan sulfate is beyond the scope of this article. However, in view of similarities of structural fea-... 

Nadanaka, S. and Kitagawa, H. (2008). Heparan sulphate biosynthesis and disease.. Biochem. 144, 7-14. 

An understanding of the structures of the molecules of heparin and heparan sulfate has come, in part, from studies with degradative enzymes, but also with biosynthetic enzymes. Both polysaccharides are based on the disaccharide unit which, in the initial stage of biosynthesis, consists of... 

Sasisekharan R, Venkataraman G. Heparin and heparan sulfate biosynthesis, structure and function. Cutr. Opin. Chem. Biol. 2000 4 626-631. 

Kim B-T, Kitagawa H, Tamura J-i, Saito T, Kusche-Gullberg M, Lindahl U, et al. Human tumor suppressor EXT gene family members EXTLl and EXTL3 encode a-1,4-V-acetylglucos-aminyltransferases that likely are involved in heparan sulfate/ heparin biosynthesis. Proc. Natl. Acad. Sci. U.S.A. 2001 98 7176-7681. 

Pinhal MAS, Smith B, Olson S, Aikawa J, Kimata K, Esko JD. Enzyme interactions in heparan sulfate biosynthesis uronosyl... 

Pedersen LC, Tsuchida K, Kitagawa H, Sugahara K, Darden TA, Negishi M. Heparan/chondroitin sulfate biosynthesis. Structure and mechanism of human glucuronyltransferase I. J. Biol. Chem. 2000 275 34580-34585. 

The initial stages of chondroitin and heparan sulfate biosynthesis. Each enzyme is defined by its shorthand name(s) as well as by the abbreviations of the relevant known or proposed corresponding Drosophila and Caenorhabditis genes... 

Hyaluronan p-GlcA/ -(1 3)-p-GlcNAc/ -(l ). The biosynthesis proceeds, apparently without any primer requirement (unlike heparan and chondroitin), by stepwise addition of UDPGlcA and UDPGlcNAc, from the non-reducing end. As with heparan, the synthetases are single polypeptides which catalyse both transfer reactions. 

---