Localization of the Binding Site for the Oligosaccharide Moiety of Gb3 on Verotoxin 1 Using NMR Residual Dipolar Coupling Measurements

• Published in: Biochemistry (Easton) Vol. 39; no. 43; pp. 13153 - 13156
• Main Authors: Thompson, Gary S, Shimizu, Hiroki, Homans, Steve W, Donohue-Rolfe, Art
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 31.10.2000
• Subjects: Binding Sites; Carbon Isotopes; Ligands; Nuclear Magnetic Resonance, Biomolecular - methods; Oligosaccharides - chemistry; Oligosaccharides - metabolism; Protons; Shiga Toxin 1 - chemistry; Shiga Toxin 1 - metabolism; Solutions; Trihexosylceramides - chemistry; Trihexosylceramides - metabolism
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi001394+

By use of NMR residual dipolar coupling measurements in a dilute liquid-crystalline solvent, the solution structure has been determined of the complex between the oligosaccharide moiety of globotriaosylceramide (Gb3-OS) and the B-subunit homopentamer of verotoxin 1 (VTB). The dipolar coupling data indicate that Gb3-OS binds in a single binding site per monomer, which is identical to one of three sites inferred from the X-ray structure of the same complex. We find no evidence within experimental error for occupancy at either of the two additional binding sites observed per monomer in the crystal structure.