Multiple Conformations of the Proline-Rich Protein/Epigallocatechin Gallate Complex Determined by Time-Averaged Nuclear Overhauser Effects

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• 作者：Adrian J. Charlton ; Edwin Haslam ; and Michael P. Williamson
• 刊名：Journal of the American Chemical Society
• 出版年：2002
• 出版时间：August 21, 2002
• 年：2002
• 卷：124
• 期：33
• 页码：9899 - 9905
• 全文大小：135K
• 年卷期：v.124,no.33(August 21, 2002)
• ISSN：1520-5126

文摘

The structure of the complex between the heptapeptide Gln-Gly-Arg-Pro-Pro-Gln-Gly and thepolyphenol (-)-epigallocatechin gallate (EGCG) has been determined using time-averaged nuclearOverhauser effects. Effective parameters for the force constant and time constant have been derived,allowing rapid and efficient calculation of structures that satisfy the input restraints. By using multiple startconformations, it is shown that conformational space is covered adequately and that the complex exists inone major conformation, in which the A ring of the EGCG is positioned over Pro5 and the D ring is overPro4, with the B ring frequently close to the arginine side chain. Alternative conformations are also found,in which the prolines are almost always both involved in stacking interactions, with a strong preference forPro4 to be involved. The structures are consistent with previous models for the interaction and suggesthow precipitation of the complex could occur, which leads to the oral phenomenon of astringency. Themethod has promise as a general way of docking ligands onto receptors.