Substrate specificity of a heparan sulfate-degrading endoglucuronidase from human placenta.
Substrate specificity of a heparan sulfate-degrading endoglucuronidase from human placenta.
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来自人胎盘的硫酸乙酰肝素降解内切葡萄糖醛酸酶的底物特异性。
DOI：
10.1515/bchm2.1979.360.2.1465
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
K. von Figura
中科院分区：
文献类型：
--
作者：
U. Klein;K. von Figura
从人胎盘中分离到一种硫酸肝素降解葡糖苷内切酶，并采用硫酸肝素- sepharose 4B亲和层析进行部分纯化。凝胶色谱法估计内切葡萄糖醛酸酶的分子量约为100,000，pH值在pH4和pH6之间。羧基还原的硫酸肝素不能被部分纯化的内切葡萄糖醛酸酶分解，但抑制酶对未修饰的硫酸肝素的作用。低分子量硫酸肝素（Mr约为3 000）不受内切葡萄糖醛酸酶的攻击。n -脱硫硫酸肝素和肝素只是弱底物。葡萄糖醛酸内切酶释放的硫酸肝素片段还原末端出现的葡萄糖醛酸残基附近的氨基糖似乎完全是n -乙酰化的葡萄糖胺。
A heparan sulfate-degrading endoglucuronidase was isolated from human placenta and partially purified by affinity chromatography on heparan sulfate-Sepharose 4B. The endoglucuronidase has a molecular weight of approximately 100 000 estimated by gel chromatography and a broad pH optimum between pH4 and pH6. Carboxyl reduced heparan sulfate is not split by partially purified endoglucuronidase, but inhibits the action of that enzyme towards non-modified heparan sulfate. Low molecular weight heparan sulfate (Mr approximately 3 000) is not attacked by the endoglucuronidase. N-Desulfated heparan sulfate and heparin are only weak substrates. The amino sugar adjacent to the glucuronic acid residue appearing at the reducing terminal of heparan sulfate fragments liberated by the endoglucuronidase appears to be exclusively N-acetylated glucosamine.