Galectin

About: Galectin is a research topic. Over the lifetime, 2076 publications have been published within this topic receiving 103409 citations. The topic is also known as: IPR001079 & Galectin.

Metazoan Soluble β-Galactoside-Binding Lectins, Galectins: Methods for Purification, Characterization of Their Carbohydrate-Binding Specificity, and Probing Their Ligands

Abstract: Galectins are a family of soluble β-galactoside-binding proteins that share conserved carbohydrate recognition domain. Galectins are found in most multicellular organisms and exert various biological functions by binding to the surface glycoconjugates as lectins. In this chapter, we describe the general methods of purification of galectins, quality control of purified galectins, some example methods of evaluating their carbohydrate-binding activity, and use of galectin to search or detect galectin ligands as well as a series of precautions for the usage of galectins.

Identification of a second, non-conserved amino acid that contributes to the unique sugar binding properties of the nematode galectin LEC-1.

Abstract: The basic disaccharide structure recognized by galectin family members is the lactosamine-like structure Galβ1-4(3)Glc(NAc). The 32-kDa galectin LEC-1 of the nematode Caenorhabditis elegans is composed of two domains, each of which is homologous to vertebrate 14-kDa-type galectins. The N-terminal lectin domain of LEC-1 recognizes blood group A saccharide (GalNAcα1-3(Fucα1-2)Galβ1-3GlcNAc), whereas this saccharide is poorly recognized by the C-terminal domain. Using a combination of site-directed mutagenesis and analysis of the sugar-binding profile by frontal affinity chromatography, we previously found that Thr41 in the N-terminal lectin domain of LEC-1 is important for its affinity for A-hexasaccharide. Thr41 is located on β-strand S3, next to the three β-strands S4—S6, where the conserved amino acids form the binding site for the basic Galβ1-4(3)Glc(NAc) structure. Here, we report that a second amino acid, Asp133, in the N-terminal lectin domain of LEC-1, located on the β-strand S2 adjacent to that containing Thr41, is important for LEC-1-specific recognition of A-hexasaccharide. These results suggest that amino acid residues other than those located on the three β-strands S4—S6, contribute to the unique sugar binding specificity of individual galectins.

Galectin 9-polymer conjugate

Abstract: Galectin 9 which is an immune function controlling factor belonging to a new class different from cytokines and expected to be applied as a therapeutic agent for various immune-related diseases including autoimmune disease has problems such as protease sensitivity, low solubility and the like which need to be solved in the development of therapeutic agent, therefore, it is intended to solve these problems. In galectin 9, particularly chemically modified galectin 9 in which a stabilized galectin 9 is conjugated to a polymer (for example, polyethylene glycol: PEG), more excellent solubility can be obtained and improvement of in vivo dynamics (for example, the prolongation of the duration of action such as the prolongation of serum half-life), the suppression of hemagglutination activity or the like has been confirmed and it has an excellent property as a pharmaceutical.

Synthesis of Fluorescence‐Labeled Galβ1‐3Fuc and Galβ1‐4Fuc as Probes for the Endogenous Glyco‐Epitope Recognized by Galectins in Caenorhabditis elegans.

Abstract: To search for the endogenous glyco-epitope in Caenorhabditis elegans, we synthesized labeled Galbeta1-3Fuc and Galbeta1-4Fuc and examined their binding affinity for C. elegans galectin LEC-6 using frontal affinity chromatography analysis. We developed a new strategy for synthesizing the labeled saccharides, in which the labeling unit, the 2-aminopyridine moiety, is coupled with a spacer unit derived from D-mannitol. Our results indicate that Galbeta1-4Fuc is the endogenous glyco-epitope present in C. elegans N-glycans.

Molecular galactose-galectin association in neuroblastoma cells: An unconventional tool for qualitative/quantitative screening.

Abstract: Purpose Galectin decorates the cell membrane and forms an extracellular molecular association with galactoside units. Here, galactoside probes have been used to study galectin expression in neuroblastoma cells. The hypothesis behind this investigation has been that the molecular mechanisms by which glycans modulate neural metastatic cells involve a protein-carbohydrate association, galectin-galactose. Experimental design Preliminary screening to validate the hypothesis has been performed with galactose moieties anchored to beads. The molecular association has been studied by FACS. In vitro experiments reveal the molecular binding preferences of the metastatic neuroblastoma cells. Ex vivo, the galactose probes discriminate healthy tissues. The unconventional assay in microfluidics used in this study displayed results analogous to the above (GI-LI-N cell capture efficiency overcomes IMR-32). Results At the point of equilibrium of shear and binding forces, the capture yield inside the chamber was measured to 60 ± 4.4% in GI-LI-N versus 40 ± 2.1% in IMR-32. Staining of the fished cells and subsequent conjugation with red beads bearing the galactose also have evidenced that microfluidics can be used to study and quantify the molecular association of galectin-galactose. Most importantly, a crucial insight for obtaining single-cell qualitative/quantitative glycome analysis has been achieved. Finally, the specificity of the assay performed in microfluidics is demonstrated by comparing GI-LI-N fishing efficiency in galactose and fucose environments. The residual adhesion to fucose confirmed the existence of receptors for this glycan and that its eventual unspecific binding (i.e. due to electrostatic interactions) is insignificant compared with the molecular binding. Conclusion Identification and understanding of this mechanism of discrimination can be relevant for diagnostic monitoring and for producing probes tailored to interfere with galectin activities associated with the malignant phenotype. Besides, the given strategy has implications for the rational design of galectin-specific ligands.