Affinity of galectin-8 and its carbohydrate recognition domains for ligands in solution and at the cell surface.
Research output: Contribution to journal › Article
Galectin-8 has two different carbohydrate recognition domains (CRDs), the N-terminal Gal-8N and the C-terminal Gal-8C linked by a peptide, and has various effects on cell adhesion and signaling. To understand the mechanism for these effects further, we compared the binding activities of galectin-8 in solution with its binding and activation of cells. We used glycan array analysis to broaden the specificity profile of the two galectin-8 CRDs, as well as intact galectin-8s (short and long linker), confirming the unique preference for sulfated and sialylated glycans of Gal-8N. Using a fluorescence anisotropy assay, we examined the solution affinities for a subset of these glycans, the highest being 50 nM for NeuAc alpha 2,3Lac by Gal-8N. Thus, carbohydrate-protein interactions can be of high affinity without requiring multivalency. More importantly, using fluorescence polarization, we also gained information on how the affinity is built by multiple weak interactions between different fragments of the glycan and its carrier molecule and the galectin CRD subsites (A-E). In intact galectin-8 proteins, the two domains act independently of each other in solution, whereas at a surface they act together. Ligands with moderate or weak affinity for the isolated CRI)s on the array are bound strongly by intact galectin-8s. Also galectin-8 binding and signaling at cell surfaces can be explained by combined binding of the two CRI)s to low or medium affinity ligands, and their highest affinity ligands, such as sialylated galactosides, are not required.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Publication status||Published - 2007|
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Organic chemistry (S/LTH) (011001240), Division of Microbiology, Immunology and Glycobiology - MIG (013025200)
Related research output
Susanne Nordenfelt, 2007, Institution of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology (MIG). 132 p.
Research output: Thesis › Doctoral Thesis (compilation)