Deciphering Mode of Action of Heparanase Using Structurally Defined Oligosaccharides
Deciphering Mode of Action of Heparanase Using Structurally Defined Oligosaccharides
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DOI：
10.1074/jbc.m112.390161
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发表时间：
2012-10-05
影响因子：
4.8
通讯作者：
Liu, Jian
中科院分区：
文献类型：
--
作者：
Peterson, Sherket;Liu, Jian
硫酸肝素（HS）是一种高度硫酸化的多糖，具有多种生物学功能，包括调节细胞生长和炎症反应以及血液凝固过程。肝素酶是一种切割HS的酶，已知在癌症、糖尿病和阿尔茨海默病中表现出多种病理生理作用。肝素酶与疾病之间的联系是其选择性切割HS的结果，其释放较小的HS片段以增强细胞增殖、迁移和侵袭。尽管HS在病理疾病中具有重要意义，但指导肝素酶裂解和HS解聚步骤的HS结构线索仍不清楚。在这里，我们试图用一系列结构上定义的寡糖底物来探测肝素酶的底物特异性。用质谱法和凝胶渗透色谱法测定了肝素酶在低聚糖底物上的裂解位点。我们发现肝素酶可以切割葡萄糖醛酸与氨基葡萄糖的连接，氨基葡萄糖携带6- o -磺基。此外，我们的研究结果表明，通过识别底物的非还原端结构，肝素酶表现出不同的切割模式。我们的研究结果加深了对肝素酶作用方式的理解。
Heparan sulfate (HS) is a highly sulfated polysaccharide that serves many biological functions, including regulating cell growth and inflammatory responses as well as the blood coagulation process. Heparanase is an enzyme that cleaves HS and is known to display a variety of pathophysiological effects in cancer, diabetes, and Alzheimer disease. The link between heparanase and diseases is a result of its selective cleavage of HS, which releases smaller HS fragments to enhance cell proliferation, migration, and invasion. Despite its importance in pathological diseases, the structural cues in HS that direct heparanase cleavage and the steps of HS depolymerization remain unknown. Here, we sought to probe the substrate specificity of heparanase using a series of structurally defined oligosaccharide substrates. The sites of heparanase cleavage on the oligosaccharide substrates were determined by mass spectrometry and gel permeation chromatography. We discovered that heparanase cleaves the linkage of glucuronic acid linked to glucosamine carrying 6-O-sulfo groups. Furthermore, our findings suggest that heparanase displays different cleavage modes by recognizing the structures of the nonreducing ends of the substrates. Our results deepen the understanding of the action mode of heparanase.