Takudrei

134
Highly dynamic motion of crown ethers along oligolysine peptide chains

D. P. Weimann, H. D. F. Winkler, J. A. Falenski, B. Koksch, C. A. Schalley— 2009

Molecular mobility has attracted considerable attention in supramolecular chemistry and biochemistry, but the simple question of whether a small molecule can move directly between different binding sites of a multitopic host without intermediate dissociation has not been addressed so far. To study such processes, we consider hydrogen/deuterium exchange experiments on a model system comprising complexes formed between 18-crown-6 and oligolysine peptides. Because direct binding-site hopping is indistinguishable in solution from a dissociation/reassociation mechanism, here we show that the high vacuum of a mass spectrometer offers a unique environment for probing such processes. The highly dynamic motion of crown ethers along oligolysine peptide chains proceeds mechanistically by a simultaneous transfer of the crown ether from its ammonium ion binding site to a nearby amino group together with a proton. Furthermore, the exchange experiments unambiguously reveal the zwitterionic structure of the 18-crown-6/oligolysine complexes, highlighting the versatility and potential of gas-phase experiments for investigating non-covalent interactions.

Title134
Highly dynamic motion of crown ethers along oligolysine peptide chains
AuthorD. P. Weimann, H. D. F. Winkler, J. A. Falenski, B. Koksch, C. A. Schalley
Date20090830
IdentifierDOI 10.1038/nchem.352
Source(s)
CitationNature Chem. 2009, 1 573-577