Cation Dependence of Chloride Ion Complexation by Open-Chained Receptor Molecules in Chloroform Solution
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- 作者：Robert Pajewski ; Riccardo Ferdani ; Jolanta Pajewska ; Ruiqiong Li ; and George W. Gokel
- 刊名：Journal of the American Chemical Society
- 出版年：2005
- 出版时间：December 28, 2005
- 年：2005
- 卷：127
- 期：51
- 页码：18281 - 18295
- 全文大小：290K
- 年卷期：v.127,no.51(December 28, 2005)
- ISSN：1520-5126
文摘
Seventeen peptides, most having the sequence GGGPGGG, but differing in the C- and N-terminalends, have been studied as anion-complexing agents. These relatively simple, open-chained peptidesystems interact with both chloride and the associated cation. Changes in the N- and C-terminal side chainsappear to make little difference in the efficacy of binding. NMR studies suggest that the primary interactionsinvolve amide NH contacts with the chloride anion, and CD spectral analyses suggest a concomitantconformational change upon binding. Changes in binding constants, which are expected in different solvents,also suggest selective solvent interactions with the unbound host that helps to preorganize the open-chained peptide system. Significant differences are apparent in complexation strengths when theheptapeptide chain is shortened or lengthened or when the relative position of proline within the heptapeptideis varied.