CONTRIBUTION OF MONOSACCHARIDE RESIDUES IN HEPARIN BINDING TO ANTITHROMBIN-III
CONTRIBUTION OF MONOSACCHARIDE RESIDUES IN HEPARIN BINDING TO ANTITHROMBIN-III
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DOI：
10.1021/bi00344a063
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发表时间：
1985-01-01
期刊：
影响因子：
2.9
通讯作者：
CHOAY, J
中科院分区：
文献类型：
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作者：
ATHA, DH;LORMEAU, JC;CHOAY, J
肝素八糖艾杜糖醛酸中3-O-和6-O-磺化氨基葡萄糖残基的重要性(1).N-乙酰氨基葡萄糖6-O-硫酸盐(2)。葡萄糖醛酸(3).N-硫酸氨基葡萄糖3，6-二O-硫酸盐(4).2-O-硫酸酯(5)。N-硫酸氨基葡萄糖6-0-硫酸盐(6).2-O-硫酸酯(7)。通过比较人工合成的四糖和五糖与人抗凝血酶的结合能力，确定了脱水甘露醇6-O-硫酸酯(8)。该八糖对抗凝血酶的亲和力为1倍。6度本征荧光增强法测得10-8M(10.2千卡/摩尔)。C.合成的五糖由2-6个残基组成，亲和力为3倍。10-8M(9.6千卡/摩尔)。相同的五糖，除了缺少残基4上的3-O-硫酸盐外，亲和力为5倍。平衡透析法测定10~(-4)M(4.5千卡/摩尔)。四糖由2-5个残基组成，与抗凝血酶结合，亲和力为5倍。10-6M(6.8千卡/摩尔)。该四糖由3-6个残基组成，亲和力为5倍。10-5M(5.5千卡/摩尔)。由于残基4的6-O-硫酸盐残基2或3-O-硫酸盐的损失导致五糖结合能损失40-50%或4-5千卡/摩尔，这两个残基肯定是结合的主要贡献者，并且必须与八糖的生物活性相联系。
The importance of 3-O- and 6-O-sulfated glucosamine residues within the heparin octasaccharide iduronic acid (1) .fwdarw. N-acetylglucosamine 6-O-sulfate (2) .fwdarw. glucuronic acid (3) .fwdarw. N-sulfated glucosamine 3,6-di-O-sulfate (4) .fwdarw. iduronic acid 2-O-sulfate (5) .fwdarw. N-sulfated glucosamine 6-0-sulfate (6) .fwdarw. iduronic acid 2-O-sulfate (7) .fwdarw. anhydromannitol 6-O-sulfate (8) was determined by comparing with synthetic tetra-and pentasaccharides its ability to bind human antithrombin. The octasaccharide had an affinity for antithrombin of 1 .times. 10-8 M (10.2 kcal/mol) measured by intrinsic fluorescence enhancement at 6.degree. C. The synthetic pentasaccharide, consisting of residues 2-6, had an affinity of 3 .times. 10-8 M (9.6 kcal/mol). The same pentasaccharide, except lacking the 3-O-sulfate on residue 4, had an affinity of 5 .times. 10-4 M (4.5 kcal/mol) measured by equilibrium dialysis. The tetrasaccharide, consisting of residues 2-5, bound antithrombin with an affinity of 5 .times. 10-6 M (6.8 kcal/mol). The tetrasaccharide, consisting of residues 3-6, had an affinity of 5 .times. 10-5 M (5.5 kcal/mol). Since the loss of either the 6-O-sulfated residue 2 or the 3-O-sulfate of residue 4 results in a 4-5 kcal/mol or a 40-50% loss in binding energy of the pentasaccharide, these two residues must be the major contributors to the binding and must be linked to the biologic activity of the octasaccharide.