THE DISACCHARIDE COMPOSITION OF HEPARINS AND HEPARAN SULFATES
THE DISACCHARIDE COMPOSITION OF HEPARINS AND HEPARAN SULFATES
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DOI：
10.1016/0003-2697(89)90278-9
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发表时间：
1989-01-01
影响因子：
2.9
通讯作者：
CONRAD, HE
中科院分区：
文献类型：
--
作者：
GUO, Y;CONRAD, HE
肝素和硫酸肝素在pH为1.5的硝酸条件下可选择性地裂解其n -硫酸氨基葡萄糖残基。这些聚合物也可以通过先用肼进行n -去乙酰化，然后在pH为4的情况下用硝酸处理产物，选择性地在其n -乙酰化的氨基葡萄糖残基上进行裂解。这些程序已被组合和优化，以将这些糖胺聚糖链转化为它们的双糖单位。将糖胺聚糖与含有1%硫酸肼的肼：水（70:30）一起加热，可以使n -去乙酰化速度快，并使醛酸残基转化为其肼衍生物的速度最小。在这些条件下，n -去乙酰化在4小时内完成。-在肼水解过程中发生的聚合物链的消除性裂解（P. N. Shaklee和H. E. Conrad, 1984）。J. 217, 187-197)被淘汰。n -去乙酰化聚合物在25℃下用硝酸在pH 3下处理15 h。然后C同时对n -未取代的氨基葡萄糖残基和n -硫酸氨基葡萄糖残基进行裂解。这些脱氨条件最小化，但没有消除，副反应中，在亚硝酸反应的氨基葡萄糖残基进行环收缩，而氨基葡萄糖键切割。因此，获得的二糖的产率是原来存在于糖胺聚糖链中的二糖的90%。由于环收缩副反应随机发生在重氮化的氨基葡萄糖残基上，PH为3的亚硝酸反应中生成的双糖被按与原糖胺聚糖链相同的比例回收。阴离子交换高压液相色谱法分析双糖[M. J. Bienkowski和H. E. Conrad(1985)]。Chem. 260,356 -365)然后对类肝素链中每种双糖类型的数量进行了定量分析。
Heparin and heparan sulfate can be cleaved selectively at their N-sulfated glucosamine residues by direct treatment with nitrous acid at pH 1.5. These polymers can also be cleaved selectively at their N-acetylated glucosamine residues by first N-deacetylating with hydrazine and then treating the products with nitrous acid at pH 4. These procedures have been combined and optimized for the conversion of these glycosaminoglycan chains into their disaccharide units. A modified hydrazinolysis procedure in which the glycosaminoglycan were heated with hydrazine:water (70:30) containing 1% hydrazine sulfate gave rapid rate of N-deacetylation and minimal conversion of the uronic acid residues to their hydrazide derivatives. Under these conditions, N-deacetylation was complete in 4 h and the .beta.-eliminative cleavage of the polymer chains that occurs during hydrazinolysis (P. N. Shaklee and H. E. Conrad (1984) Biochem. J. 217, 187-197) was eliminated. Treatment of the N-deacetylated polymer with nitrous acid at pH 3 for 15 h at 25.degree. C then gave simultaneous cleavage at the N-unsubstituted glucosamine residues and the N-sulfated glucosamine residues. These deamination conditions minimized, but did not eliminate, the side reaction in which nitrous acid-reactive glucosamine residues undergo ring contraction without glucosaminide bond cleavage. Thus, the disaccharides were obtained in a yield of 90% of those originally present in the glycosaminoglycan chains. Since the ring contraction side reaction occurs randomly at the diazotized glucosamine residues, the disaccharides formed in the PH 3 nitrous acid reaction were recovered in proportions equal to those in the original glycosaminoglycan chain. Anion-exchange high-pressure liquid chromatography analysis of the disaccharides (M. J. Bienkowski and H. E. Conrad (1985) J. Biol. Chem. 260, 356-365) then gave quantitative analyses of the amounts of each disaccharide type in the heparinoid chain.