Crystallography Research Today is a free monthly online journal that collates and summarizes the latest research about Crystallography, including details on x-ray crystals, techniques, analyses, structures.

Crystallographic studies of the complexes of antiviral protein griffithsin with glucose and N-acetylglucosamine.

Ziółkowska NE, Shenoy SR, O'Keefe BR, Wlodawer A

Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, NCI-Frederick, MD 21702-1201, USA.

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.

Published 25 June 2007 in Protein Sci, 16(7): 1485-9.
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