Lindahl U
Department of Veterinary Medical Chemistry, Swedish University of Agricultural Sciences, Uppsala.
Haemostasis. 1990;20 Suppl 1:146-53. doi: 10.1159/000216173.
The biosynthesis of heparin is initiated by formation of [GlcA-GlcNAc]n polysaccharide chains linked to the core protein of a proteoglycan structure. The polymer is transformed into the mature polysaccharide by a series of modification reactions which involve N-deacetylation and N-sulfation of GlcNAc units, C5 epimerization of GlcA to IdoA residues, and O-sulfation at different positions. Incomplete modification, controlled in part by the substrate specificities of the corresponding enzymes, provides the complex saccharide sequences that are typical for heparin and, in particular, for heparan sulfate. One such structure is the antithrombin-binding region which is comprised by a specific pentasaccharide sequence with a 3-O-sulfated GlcN marker group. Aspects of regulation of polymer modification are discussed.
肝素的生物合成始于与蛋白聚糖结构核心蛋白相连的[GlcA-GlcNAc]n多糖链的形成。该聚合物通过一系列修饰反应转化为成熟多糖，这些反应包括GlcNAc单元的N-脱乙酰化和N-硫酸化、GlcA向IdoA残基的C5差向异构化以及不同位置的O-硫酸化。修饰不完全部分受相应酶的底物特异性控制，产生了肝素尤其是硫酸乙酰肝素特有的复杂糖序列。其中一种结构是抗凝血酶结合区域，它由一个带有3-O-硫酸化GlcN标记基团的特定五糖序列组成。本文还讨论了聚合物修饰的调控方面。
