Researchers from the NMR group at the Institut de Biologie Structurale have reported the first direct experimental evidence of biological XH/π interactions, a weak hydrogen bond-like interaction long believed to contribute to biomolecular structure and function. XH/π interactions are weaker than canonical hydrogen bonds and are commonly identified indirectly from high resolution 3D structures. Through the use a new, ultra-sensitive isotope labelling approach (also developed at the IBS) NMR researchers were able to detect these weak interactions using 2D heteronuclear NMR experiments. With this approach they were able to unambiguously identify the corresponding donor and acceptor groups and detect XH/π interactions not previously predicted from 3D structural models.
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