Abstract:
:Hydrogen bonds and their relative strengths in proteins are of importance for understanding protein structure and protein motions. The correct strength of such hydrogen bonds is experimentally known to vary greatly from approximately 5-6 kcal/mol for the isolated bond to approximately 0.5-1.5 kcal/mol for proteins in solution. To estimate these bond strengths, here we suggest a direct novel kinetic procedure. This analyzes the timing of the trajectories of a properly averaged dynamic ensemble. Here we study the observed rupture of these hydrogen bonds in a molecular dynamics calculation as an alternative to using thermodynamics. This calculation is performed for the isolated system and contrasted with results for water. We find that the activation energy for the rupture of the hydrogen bond in a beta-sheet under isolated conditions is 4.76 kcal/mol, and the activation energy is 1.58 kcal/mol for the same beta-sheet in water. These results are in excellent agreement with observations and suggest that such a direct calculation can be useful for the prediction of hydrogen bond strengths in various environments of interest.
journal_name
Proc Natl Acad Sci U S Aauthors
Sheu SY,Yang DY,Selzle HL,Schlag EWdoi
10.1073/pnas.2133366100keywords:
subject
Has Abstractpub_date
2003-10-28 00:00:00pages
12683-7issue
22eissn
0027-8424issn
1091-6490pii
2133366100journal_volume
100pub_type
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