AUTHOR=Dingjan Tamir , Imberty Anne , Pérez Serge , Yuriev Elizabeth , Ramsland Paul A. 

TITLE=Molecular Simulations of Carbohydrates with a Fucose-Binding Burkholderia ambifaria Lectin Suggest Modulation by Surface Residues Outside the Fucose-Binding Pocket

JOURNAL=Frontiers in Pharmacology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2017.00393

DOI=10.3389/fphar.2017.00393

ISSN=1663-9812

ABSTRACT=<p><italic>Burkholderia ambifaria</italic> is an opportunistic respiratory pathogen belonging to the <italic>Burkholderia cepacia</italic> complex, a collection of species responsible for the rapidly fatal cepacia syndrome in cystic fibrosis patients. A fucose-binding lectin identified in the <italic>B. ambifaria</italic> genome, BambL, is able to adhere to lung tissue, and may play a role in respiratory infection. X-ray crystallography has revealed the bound complex structures for four fucosylated human blood group epitopes (blood group B, H type 1, H type 2, and Le<sup>x</sup> determinants). The present study employed computational approaches, including docking and molecular dynamics (MD), to extend the structural analysis of BambL-oligosaccharide complexes to include four additional blood group saccharides (A, Le<sup>a</sup>, Le<sup>b</sup>, and Le<sup>y</sup>) and a library of blood-group-related carbohydrates. Carbohydrate recognition is dominated by interactions with fucose via a hydrogen-bonding network involving Arg15, Glu26, Ala38, and Trp79 and a stacking interaction with Trp74. Additional hydrogen bonds to non-fucose residues are formed with Asp30, Tyr35, Thr36, and Trp74. BambL recognition is dominated by interactions with fucose, but also features interactions with other parts of the ligands that may modulate specificity or affinity. The detailed computational characterization of the BambL carbohydrate-binding site provides guidelines for the future design of lectin inhibitors.</p>