title: Human galectin-2 interacts with carbohydrates and peptides non-classically: new insight from X-ray crystallography and hemagglutination.
abstract: 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.
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Yunlong
authors: Y
authors: Si
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Shiqiong
authors: S
authors: Feng
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Jin
authors: J
authors: Gao
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Yue
authors: Y
authors: Wang
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Zhongyu
authors: Z
authors: Zhang
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Yue
authors: Y
authors: Meng
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Yifa
authors: Y
authors: Zhou
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
authors: Guihua
authors: G
authors: Tai
authors: Jilin Province Key Laboratory on Chemistry and Biology of Natural Drugs in Changbai Mountain, School of Life Sciences, Northeast Normal University, Changchun 130024, China sujy100@nenu.edu.cn.
authors: Jiyong
authors: J
authors: Su
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D018360:Crystallography, X-Ray; D037501:Galectin 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006384:Hemagglutination / Q000187:drug effects; D006386:Hemagglutination Tests; D006801:Humans; D007785:Lactose / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011134:Polysaccharides / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation; D000072417:Protein Domains; D055503:Protein Multimerization
chemical_list: D000596:Amino Acids; D037501:Galectin 2; D010455:Peptides; D011134:Polysaccharides; D007785:Lactose
keywords: carbohydrate recognition domain; hemagglutination assay; human galectin-2 crystal structure