Human galectin-2 interacts with carbohydrates and peptides non-classically: new insight from X-ray crystallography and hemagglutination
Human galectin-2 interacts with carbohydrates and peptides non-classically: new insight from X-ray crystallography and hemagglutination
复制标题
人半乳糖凝集素 2 与碳水化合物和肽的非经典相互作用：来自 X 射线晶体学和血凝的新见解
DOI：
10.1093/abbs/gmw089
复制
发表时间：
2016-10-01
影响因子：
3.7
通讯作者：
Su, Jiyong
中科院分区：
文献类型：
--
作者：
Si, Yunlong;Feng, Shiqiong;Su, Jiyong
半乳糖凝集素-2（Galectin-2，Gal-2）在癌症、心肌梗死、免疫应答和胃肠道疾病中起作用。唯一报道的Gal-2的晶体结构表明，它是一种二聚体，其中单体亚基具有几乎相同的结构，每个亚基与一个乳糖分子结合。在这项研究中，我们在新的条件下结晶Gal-2，产生三种晶体结构。在每个Gal-2二聚体结构中，乳糖仅与一个碳水化合物识别结构域亚基结合。在溶液研究中，热位移测定表明，Gal-2二聚体中的不等价单体亚基在配体结合后变得等价。此外，半乳糖凝集素介导的红细胞凝集试验，使用乳糖和较大的复合多糖作为抑制剂显示Gal-1和Gal-2之间的结构差异。总的来说，我们的研究结果揭示了一些新的方面Gal-2的结构分化，并扩大了可能是特定于这种凝集素的不同类型的分子相互作用的潜力。
Galectin-2 (Gal-2) plays a role in cancer, myocardial infarction, immune response, and gastrointestinal tract diseases. The only reported crystal structure of Gal-2 shows that it is a dimer in which the monomer subunits have almost identical structures, each binding with one molecule of lactose. In this study, we crystallized Gal-2 under new conditions that produced three crystal structures. In each Gal-2 dimer structure, lactose was shown to be bound to only one of the carbohydrate recognition domain subunits. In solution studies, the thermal shift assay demonstrated that inequivalent monomer subunits in the Gal-2 dimer become equivalent upon ligand binding. In addition, galectin-mediated erythrocyte agglutination assays using lactose and larger complex polysaccharides as inhibitors showed the structural differences between Gal-1 and Gal-2. Overall, our results reveal some novel aspects to the structural differentiation in Gal-2 and expand the potential for different types of molecular interactions that may be specific to this lectin.