Conrad H E
Biochem J. 1980 Nov 1;191(2):355-63. doi: 10.1042/bj1910355.
Heparan sulphate, heparin and dermatan sulphate were hydrolysed in 0.5M-H2SO4 at 100 degrees C. At intervals portions of the hydrolysate were removed and treated with HNO2 at pH 4.0 to cleave the glycosidic bonds of the N-unsubstituted hexosamine residues and to convert both free and combined hexosamines into anhydrohexoses. These hydrolysis/deamination mixtures were reduced with NaB3H4 and analysed by radiochromatography for alpha-L-iduronosylanhydrohexose, beta-D-glucuronosylanhydrohexose, and the free uronic acids and anhydrohexose. These data gave a kinetic profile of the cleavage of the alpha-L-iduronosyl and the beta-D-glucuronosyl bonds in these glycosaminoglycans. The beta-D-glucuronosyl bonds showed the expected resistance to acid hydrolysis, but the alpha-L-iduronosyl bonds were found to be as labile to acid as some neutral sugar glycosides. This unusual lability of alpha-D-iduronosyl-anhydromannitol and beta-D-glucuronosylanhydromannitol. The procedures used to follow the kinetics of glycosaminoglycan hydrolysis can also be sued to obtain quantitative analyses of L-iduronic acid, D-glucuronic acid and hexosamine in these polymers.
硫酸乙酰肝素、肝素和硫酸皮肤素在0.5M - H₂SO₄中于100℃水解。每隔一段时间取出部分水解产物，在pH 4.0条件下用HNO₂处理，以裂解N - 未取代己糖胺残基的糖苷键，并将游离和结合的己糖胺都转化为脱水己糖。这些水解/脱氨混合物用NaB₃H₄还原，并通过放射色谱法分析α - L - 艾杜糖醛酸基脱水己糖、β - D - 葡萄糖醛酸基脱水己糖以及游离糖醛酸和脱水己糖。这些数据给出了这些糖胺聚糖中α - L - 艾杜糖醛酸基和β - D - 葡萄糖醛酸基键裂解的动力学曲线。β - D - 葡萄糖醛酸基键表现出预期的对酸水解的抗性，但发现α - L - 艾杜糖醛酸基键对酸的稳定性与一些中性糖苷一样不稳定。α - D - 艾杜糖醛酸基 - 脱水甘露糖醇和β - D - 葡萄糖醛酸基脱水甘露糖醇具有这种不寻常的不稳定性。用于跟踪糖胺聚糖水解动力学的方法也可用于对这些聚合物中的L - 艾杜糖醛酸、D - 葡萄糖醛酸和己糖胺进行定量分析。
