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Amide-to-E-olefin versus amide-to-ester backbone H-bond perturbations: Evaluating the O-O repulsion for extracting H-bond energies.

ABSTRACT: Both amide-to-ester and amide-to-E-olefin backbone amide mutation methods were employed to perturb the same H-bond (formed by the NH of F23 and the CO of R14) in the Pin WW domain. Comparison of the thermodynamic folding energies of the ester mutant and the E-olefin mutant, accounting for the transfer free energy differences measured on relevant model compounds, yielded an estimated value of 0.3 kcal/mol for the O-O repulsion term (DeltaGO-Orep) in a beta-sheet context. The value of DeltaGO-Orep enabled us to calculate the intrinsic F23-R14 H-bond free energy to be 1.3 kcal/mol.

SUBMITTER: Fu Y

PROVIDER: S-EPMC2532496 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature

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Amide-to-E-olefin versus amide-to-ester backbone H-bond perturbations: Evaluating the O-O repulsion for extracting H-bond energies.

Fu Yanwen Y Gao Jianmin J Bieschke Jan J Dendle Maria A MA Kelly Jeffery W JW

Journal of the American Chemical Society 20061201 50

Both amide-to-ester and amide-to-E-olefin backbone amide mutation methods were employed to perturb the same H-bond (formed by the NH of F23 and the CO of R14) in the Pin WW domain. Comparison of the thermodynamic folding energies of the ester mutant and the E-olefin mutant, accounting for the transfer free energy differences measured on relevant model compounds, yielded an estimated value of 0.3 kcal/mol for the O-O repulsion term (DeltaGO-Orep) in a beta-sheet context. The value of DeltaGO-Orep ...[more]

PMID: 17165703

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