Simple Cation- Interaction between a Phenyl Ring and a Protonated Amine Stabilizes an 
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- 作者：Lun K. Tsou ; Chad D. Tatko ; and Marcey L. Waters
- 刊名：Journal of the American Chemical Society
- 出版年：2002
- 出版时间：December 18, 2002
- 年：2002
- 卷：124
- 期：50
- 页码：14917 - 14921
- 全文大小：86K
- 年卷期：v.124,no.50(December 18, 2002)
- ISSN：1520-5126
文摘
Cation-
interactions have been proposed to be important contributors to protein structure andfunction. In particular, these interactions have been suggested to provide significant stability at the solvent-exposed surface of a protein. We have investigated the magnitude of cation- interactions betweenphenylalanine (Phe) and lysine (Lys), ornithine (Orn), and diaminobutanoic acid (Dab) in the context of an
-helix and have found that only the Phe···Orn interaction provides significant stability to the helix, stabilizingit by -0.4 kcal/mol. This interaction energy is in the same range as a salt bridge in an -helix, and equivalentto the recently reported Trp···Arg interaction in an -helix, despite the fact that Trp···guanidinium interactionshave been proposed to be stronger than Phe···ammonium interactions. These results indicate that eventhe simplest cation- interaction can provide significant stability to protein structure and demonstrate thesubtle factors that can influence the observed interaction energies in designed systems.
interactions have been proposed to be important contributors to protein structure andfunction. In particular, these interactions have been suggested to provide significant stability at the solvent-exposed surface of a protein. We have investigated the magnitude of cation- interactions betweenphenylalanine (Phe) and lysine (Lys), ornithine (Orn), and diaminobutanoic acid (Dab) in the context of an-helix and have found that only the Phe···Orn interaction provides significant stability to the helix, stabilizingit by -0.4 kcal/mol. This interaction energy is in the same range as a salt bridge in an -helix, and equivalentto the recently reported Trp···Arg interaction in an -helix, despite the fact that Trp···guanidinium interactionshave been proposed to be stronger than Phe···ammonium interactions. These results indicate that eventhe simplest cation- interaction can provide significant stability to protein structure and demonstrate thesubtle factors that can influence the observed interaction energies in designed systems.