TY - JOUR
T1 - Epitope mapping of histo blood group antigens bound to norovirus VLPs using STD NMR experiments reveals fine details of molecular recognition
AU - Fiege, Brigitte
AU - Leuthold, Mila
AU - Parra, Francisco
AU - Dalton, Kevin P.
AU - Meloncelli, Peter J.
AU - Lowary, Todd L.
AU - Peters, Thomas
N1 - Funding Information:
Acknowledgments Financial support from the DFG (PE494/8-1 and PE494,12-1 with the research unit FOR2327) is gratefully acknowledged. The authors thank the University of Lübeck and the Alberta Glycomics Centre for financial support. The DFG and the state of Schleswig-Holstein are thanked for a grant for the cryogenic probe (HBFG 101/192-1). FP and KPD were supported by grant GRUPIN14-099 from Principado de Asturias (Spain), cofinanced by FEDER. Prof. Monica Palcic (University of Victoria, BC, Canada) is thanked for a kind gift of the blood group B-trisaccharide. Dr. Alvaro Mallagaray from the University of Lübeck and Dr. Grant Hansman from the DKFZ in Heidelberg are thanked for stimulating discussions. Dr. Thorsten Biet, Thies Köhli, and Wilfried Hellebrandt are thanked for technical assistance.
Publisher Copyright:
© 2017, Springer Science+Business Media, LLC.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Attachment of human noroviruses to histo blood group antigens (HBGAs) is thought to be critical for the infection process. Therefore, we have determined binding epitopes of synthetic type 1 to 6 blood group A- and B-tetrasaccharides binding to GII.4 human Norovirus virus like particles (VLPs) using STD NMR experiments. So far, little information is available from crystal structure analysis studies on the interactions of the reducing-end sugars with the protruding domain (P-domain) of the viral coat protein VP1. Here, we show that the reducing-end sugars make notable contacts with the protein surface. The type of glycosidic linkage, and the identity of the sugar at the reducing end modulate HBGA recognition. Most strikingly, type 2 structures yield only very poor saturation transfer indicating impeded binding. This observation is in accordance with previous mass spectrometry based affinity measurements, and can be understood based on recent crystal structure data of a complex of highly homologous GII.4 P-dimers with H-type 2 trisaccharide where the N-acetyl group of the reducing N-acetyl glucosamine residue points towards a loop comprising amino acids Q390 to H395. We suggest that in our case, binding of type 2 A- and B-tetrasaccharides leads to steric conflicts with this loop. In order to identify factors determining L-Fuc recognition, we also synthesized GII.4 VLPs with point mutations D391A and H395A. Prior studies had suggested that these residues, located in a second shell around the L-Fuc binding site, assist L-Fuc binding. STD NMR experiments with L-Fuc and B-trisaccharide in the presence of wild type and mutant VLPs yield virtually identical binding epitopes suggesting that these two mutations do not significantly alter HBGA recognition. Our study emphasizes that recognition of α−(1→2)-linked L-Fuc residues is a conserved feature of GII.4 noroviruses. However, structural variation of the HBGA core structures clearly modulates molecular recognition depending on the genotype.
AB - Attachment of human noroviruses to histo blood group antigens (HBGAs) is thought to be critical for the infection process. Therefore, we have determined binding epitopes of synthetic type 1 to 6 blood group A- and B-tetrasaccharides binding to GII.4 human Norovirus virus like particles (VLPs) using STD NMR experiments. So far, little information is available from crystal structure analysis studies on the interactions of the reducing-end sugars with the protruding domain (P-domain) of the viral coat protein VP1. Here, we show that the reducing-end sugars make notable contacts with the protein surface. The type of glycosidic linkage, and the identity of the sugar at the reducing end modulate HBGA recognition. Most strikingly, type 2 structures yield only very poor saturation transfer indicating impeded binding. This observation is in accordance with previous mass spectrometry based affinity measurements, and can be understood based on recent crystal structure data of a complex of highly homologous GII.4 P-dimers with H-type 2 trisaccharide where the N-acetyl group of the reducing N-acetyl glucosamine residue points towards a loop comprising amino acids Q390 to H395. We suggest that in our case, binding of type 2 A- and B-tetrasaccharides leads to steric conflicts with this loop. In order to identify factors determining L-Fuc recognition, we also synthesized GII.4 VLPs with point mutations D391A and H395A. Prior studies had suggested that these residues, located in a second shell around the L-Fuc binding site, assist L-Fuc binding. STD NMR experiments with L-Fuc and B-trisaccharide in the presence of wild type and mutant VLPs yield virtually identical binding epitopes suggesting that these two mutations do not significantly alter HBGA recognition. Our study emphasizes that recognition of α−(1→2)-linked L-Fuc residues is a conserved feature of GII.4 noroviruses. However, structural variation of the HBGA core structures clearly modulates molecular recognition depending on the genotype.
UR - http://www.scopus.com/inward/record.url?scp=85027717904&partnerID=8YFLogxK
U2 - 10.1007/s10719-017-9792-5
DO - 10.1007/s10719-017-9792-5
M3 - Journal articles
C2 - 28823097
AN - SCOPUS:85027717904
SN - 0282-0080
VL - 34
SP - 679
EP - 689
JO - Glycoconjugate Journal
JF - Glycoconjugate Journal
IS - 5
ER -