Low or No Inhibitory Potency of the Canonical Galectin Carbohydrate-binding Site by Pectins and Galactomannans

Autor: Matilde Aguilar-Moncayo, Adriana Lepur, Hakon Leffler, John Stegmayr, Anatole A. Klyosov, Robert A. Field, Ulf J. Nilsson, Stina Oredsson, Barbro Kahl-Knutson
Rok vydání: 2016
Předmět:
0301 basic medicine
animal structures
Galectins
Glycobiology and Extracellular Matrices
Antineoplastic Agents
Fluorescence Polarization
fluorescence anisotropy
Polysaccharide
Biochemistry
Mannans
Inhibitory Concentration 50
03 medical and health sciences
chemistry.chemical_compound
Galactomannan
glycobiology
Polysaccharides
Cell Line
Tumor

Manchester Institute of Biotechnology
otorhinolaryngologic diseases
Humans
Binding site
Molecular Biology
Galectin
pectin
chemistry.chemical_classification
Binding Sites
galectin
davanat
Hemagglutination
Galactose
Cell Biology
Carbohydrate
Oligosaccharide
Galactan
ResearchInstitutes_Networks_Beacons/manchester_institute_of_biotechnology
3. Good health
stomatognathic diseases
030104 developmental biology
chemistry
pectasol
polysaccharide
galactomannan
Pectins
cancer therapy
hemagglutination
Drug Screening Assays
Antitumor

Protein Binding
Zdroj: Stegmayr, J, Lepur, A, Kahl-Knutson, B, Aguilar-Moncayo, M, Klyosov, A A, Field, R A, Oredsson, S, Nilsson, U J & Leffler, H 2016, ' Low or No Inhibitory Potency of the Canonical Galectin Carbohydrate-binding Site by Pectins and Galactomannans ', Journal of Biological Chemistry . https://doi.org/10.1074/jbc.M116.721464
The Journal of Biological Chemistry
ISSN: 0021-9258
DOI: 10.1074/jbc.m116.721464
Popis: Some complex plant-derived polysaccharides, such as modified citrus pectins and galactomannans, have been shown to have promising anti-inflammatory and anti-cancer effects. Most reports propose or claim that these effects are due to interaction of the polysaccharides with galectins because the polysaccharides contain galactose-containing side chains that might bind this class of lectin. However, their direct binding to and/or inhibition of the evolutionarily conserved galactoside-binding site of galectins has not been demonstrated. Using a well established fluorescence anisotropy assay, we tested the direct interaction of several such polysaccharides with physiological concentrations of a panel of galectins. The bioactive pectic samples tested were very poor inhibitors of the canonical galactoside-binding site for the tested galectins, with IC50 values >10 mg/ml for a few or in most cases no inhibitory activity at all. The galactomannan Davanat® was more active, albeit not a strong inhibitor (IC50 values ranging from 3 to 20 mg/ml depending on the galectin). Pure synthetic oligosaccharide fragments found in the side chains and backbone of pectins and galactomannans were additionally tested. The most commonly found galactan configuration in pectins had no inhibition of the galectins tested. Galactosylated tri- and pentamannosides, representing the structure of Davanat®, had an inhibitory effect of galectins comparable with that of free galactose. Further evaluation using cell-based assays, indirectly linked to galectin-3 inhibition, showed no inhibition of galectin-3 by the polysaccharides. These data suggest that the physiological effects of these plant polysaccharides are not due to inhibition of the canonical galectin carbohydrate-binding site.
Databáze: OpenAIRE