Galectin-13, a Different Prototype Galectin, does not Bind β-galacto-sides and Forms Dimers via Intermolecular Disulfide Bridges Between Cys-136 and Cys-138

Su J, et al., 8(1):980, Sci Rep., 2018

Galectin-13 (Gal-13) is a prototype galectin. It is predominantly expressed in the placenta and plays a key role in pregnancy. Reported herein are the crystal structure of Gal-13 and the discovery of its structure-function relationships using biochemical and cellular studies. Bio-Layer Interferometry (BLI) was used to assess binding affinities of Gal-13 and Gal-3 towards polysaccharides, including ginseng pectin RG-I-4 (a type of rhamnogalacturonan I pectin). A Pall ForteBio Octet RED96 system equipped with Ni-NTA (NTA) Biosensor probes was used to perform all BLI experiments. His-tagged Gal-3/His-tagged Gal-13 was immobilized onto NTA sensor tips. Loaded sensor tips were then dipped in wells containing different concentrations of polysaccharide samples. Data were fitted using 1:1 binding model. Equilibrium dissociation constants (KD) were determined. Overall results of this investigation suggest that galectin-13 is a new type of prototype galectin with unique properties.

Read More