Hydrogen-Bonding Interactions in T-2 Toxin Studied Using Solution and Solid-State NMR

Toxins

Praveen Chaudhary¹  Roxanne A. Shank¹  Tony Montina¹  James T. Goettel¹  Nora A. Foroud²  Paul Hazendonk¹ 

[1] Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge AB T1K 3M4, Canada;Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge AB T1J 4B1, Canada;

关键词: T-2 toxin;    trichothecene;    NMR;    hydrogen-bonding;    ribosome;    toxin;    epoxide;    water bridging;    deuterium exchange;    chemical exchange;   

DOI  :  10.3390/toxins3101310

来源: mdpi

【 摘 要 】

The structure of T-2 toxin in the solid-state is limited to X-ray crystallographic studies, which lack sufficient resolution to provide direct evidence for hydrogen-bonding interactions. Furthermore, its solution-structure, despite extensive Nuclear Magnetic Resonance (NMR) studies, has provided little insight into its hydrogen-bonding behavior, thus far. Hydrogen-bonding interactions are often an important part of biological activity. In order to study these interactions, the structure of T-2 toxin was compared in both the solution- and solid-state using NMR Spectroscopy. It was determined that the solution- and solid-state structure differ dramatically, as indicated by differences in their carbon chemical shifts, these observations are further supported by solution proton spectral parameters and exchange behavior. The slow chemical exchange process and cross-relaxation dynamics with water observed between the hydroxyl hydrogen on C-3 and water supports the existence of a preferential hydrogen bonding interaction on the opposite side of the molecule from the epoxide ring, which is known to be essential for trichothecene toxicity. This result implies that these hydrogen-bonding interactions could play an important role in the biological function of T-2 toxin and posits towards a possible interaction for the trichothecene class of toxins and the ribosome. These findings clearly illustrate the importance of utilizing solid-state NMR for the study of biological compounds, and suggest that a more detailed study of this whole class of toxins, namely trichothecenes, should be pursued using this methodology.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland