肝素是硫酸化的D-葡糖胺、D-葡糖醛酸和L-艾杜糖醛酸的聚合体。市售肝素的分子量差异甚大:5000～30000。肝素由于来源的不同,其结构和抗凝活性也不同。肝素与抗凝血酶Ⅱ(AT-Ⅱ)的赖氨酸残基结合,使AT-Ⅱ发生构型改变,促进AT-Ⅱ活性部位与凝血酶等因子结合,以发挥抗凝活 Heparin is a polymer of sulfated D-glucosamine, D-glucuronic acid and L-iduronic acid. The molecular weight of heparin is very different: 5000 ~ 30000. Due to the different sources of heparin, its structure and anticoagulant activity are also different. Heparin and antithrombin Ⅱ (AT-Ⅱ) lysine residue binding, AT-Ⅱ configuration changes, and promote AT-Ⅱ active site and thrombin and other factors to play a role in anticoagulant activity