Characterization of the recognition of blood group B trisaccharide derivatives by the lectin from Marasmius oreades using frontal affinity chromatography-mass spectrometry

Abstract

A novel lectin from the mushroom Marasmius oreades (MOA) has been shown to bind to human blood group B oligosaccharides [1]. In the present work we examine the binding of a series of analogues of the blood group B-trisaccharide, αGal(1-3)[αFuc(1-2)]βGal-OR (1, R = (CH 2 ) 8 COOMe). MOA was biotinylated and immobilized on a micro column (9.8 μL) for evaluation by Frontal Affinity Chromatography-Mass Spectrometry (FAC-MS) [2]. The trisaccharide 1 was found to be the epitope needed for maximum recognition ( K d = 3.6 μM). A series of synthetic deoxygenated and O-methylated analogues of the B-trisaccharide (R = OMe) were then screened against the lectin, and the key structural elements for binding were determined. OH-4 of the β-Gal residue and OH-2 of the α-Gal residue were found to be critical for recognition. The FAC-MS technique also proved powerful in evaluating mixtures of compounds. Since the solution NMR structure and crystal structure of the B-trisaccharide are known [3], we propose the specific surface of the trisaccharide that is recognized by the lectin. Published in 2003.