Genetically-Encoded Fragment-Based Discovery of Glycopeptide Ligands for Carbohydrate-Binding Proteins.Ng, S., Lin, E., Kitov, P.I., Tjhung, K.F., Gerlits, O.O., Deng, L., Kasper, B., Sood, A., Paschal, B.M., Zhang, P., Ling, C.C., Klassen, J.S., Noren, C.J., Mahal, L.K., Woods, R.J., Coates, L., Derda, R.
(2015) J.Am.Chem.Soc. 137: 5248
- PubMed: 25860443
- DOI: 10.1021/ja511237n
- PubMed Abstract:
We describe an approach to accelerate the search for competitive inhibitors for carbohydrate-recognition domains (CRDs). Genetically encoded fragment-based discovery (GE-FBD) uses selection of phage-displayed glycopeptides to dock a glycan fragment a ...
We describe an approach to accelerate the search for competitive inhibitors for carbohydrate-recognition domains (CRDs). Genetically encoded fragment-based discovery (GE-FBD) uses selection of phage-displayed glycopeptides to dock a glycan fragment at the CRD and guide selection of synergistic peptide motifs adjacent to the CRD. Starting from concanavalin A (ConA), a mannose (Man)-binding protein, as a bait, we narrowed a library of 10(8) glycopeptides to 86 leads that share a consensus motif, Man-WYD. Validation of synthetic leads yielded Man-WYDLF that exhibited 40-50-fold enhancement in affinity over methyl α-d-mannopyranoside (MeMan). Lectin array suggested specificity: Man-WYD derivative bound only to 3 out of 17 proteins—ConA, LcH, and PSA—that bind to Man. An X-ray structure of ConA:Man-WYD proved that the trimannoside core and Man-WYD exhibit identical CRD docking, but their extra-CRD binding modes are significantly different. Still, they have comparable affinity and selectivity for various Man-binding proteins. The intriguing observation provides new insight into functional mimicry of carbohydrates by peptide ligands. GE-FBD may provide an alternative to rapidly search for competitive inhibitors for lectins.
‡Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6475, United States.,#Alberta Glycomics Centre, Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada.,∥Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602,United States.,∇School of Chemistry, National University of Ireland, Galway, University Road, Galway, Ireland.,⊥New England Biolabs, Ipswich, Massachusetts 01938, United States.,†Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.,§Biomedical Chemistry Institute, Department of Chemistry, New York University, New York, New York 10003, United States.