Crystallographic studies of the complexes of antiviral protein griffithsin with glucose and N-acetylglucosamine
Ziolkowska, N.E., Shenoy, S.R., O'Keefe, B.R., Wlodawer, A.(2007) Protein Sci 16: 1485-1489
- PubMed: 17567736 
- DOI: https://doi.org/10.1110/ps.072889407
- Primary Citation of Related Structures:  
2NU5, 2NUO - PubMed Abstract: 
Crystal structures of complexes of an antiviral lectin griffithsin (GRFT) with glucose and N-acetylglucosamine were solved and refined at high resolution. In both complexes, all six monosaccharide-binding sites of GRFT were occupied and the mode of binding was similar to that of mannose. In our previous attempts to obtain a complex with N-acetylglucosamine by soaking, only a single site was occupied; thus, cocrystallization was clearly superior despite lower concentration of the ligand. Isothermal titration calorimetric experiments with N-acetylglucosamine, glucose, and mannose provided enthalpic evidence of distinct binding differences between the three monosaccharides. A comparison of the mode of binding of different monosaccharides is discussed in the context of the antiviral activity of GRFT, based on specific binding to high-mannose-containing complex carbohydrates found on viral envelopes.
Organizational Affiliation: 
Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, NCI-Frederick, MD 21702-1201, USA.