Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201, United States.
J Med Chem. 2020 Apr 23;63(8):4227-4255. doi: 10.1021/acs.jmedchem.0c00156. Epub 2020 Apr 7.
Heparanase cleaves polymeric heparan sulfate (HS) molecules into smaller oligosaccharides, allowing for release of angiogenic growth factors promoting tumor development and autoreactive immune cells to reach the insulin-producing β cells. Interaction of heparanase with HS chains is regulated by specific substrate sulfation sequences. We have synthesized 11 trisaccharides that are highly tunable in structure and sulfation pattern, allowing us to determine how heparanase recognizes HS substrate and selects a favorable cleavage site. Our study shows that (1) -SO at +1 subsite and 6--SO at -2 subsite of trisaccharides are critical for heparanase recognition, (2) addition of 2--SO at the -1 subsite and of 3--SO to GlcN unit is not advantageous, and (3) the anomeric configuration (α or β) at the reducing end is crucial in controlling heparanase activity. Our study also illustrates that the α-trisaccharide having - and 6--SO at -2 and +1 subsites inhibited heparanase and was resistant toward hydrolysis.
乙酰肝素酶将聚合的硫酸乙酰肝素（HS）分子切割成较小的寡糖，从而释放出促进肿瘤发展的血管生成生长因子和自身反应性免疫细胞，使其能够到达产生胰岛素的β细胞。乙酰肝素酶与 HS 链的相互作用受到特定底物硫酸化序列的调节。我们已经合成了 11 种三糖，它们在结构和硫酸化模式上具有高度的可调节性，使我们能够确定乙酰肝素酶如何识别 HS 底物并选择有利的切割位点。我们的研究表明：（1）三糖的+1 亚基上的 -SO 和 -2 亚基上的 6--SO 对乙酰肝素酶的识别至关重要；（2）在-1 亚基上添加 2--SO 和在 GlcN 单元上添加 3--SO 没有优势；（3）在还原端的糖苷构型（α 或 β）对控制乙酰肝素酶活性至关重要。我们的研究还表明，在-2 和+1 亚基上具有 - 和 6--SO 的α-三糖抑制了乙酰肝素酶，并且对水解具有抗性。
