Pseudo-prolines: Induction of cis/trans-conformational interconversion by decreased transition state barriers
✍ Scribed by Manfred Mutter; Torsten Wöhr; Séverine Gioria; Michael Keller
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1999
- Tongue
- English
- Weight
- 169 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
Molecular events such as cis/trans isomerization of Xaa-Pro tertiary amide bonds in peptides and proteins are slow on the overall time scale of the formation of a final biostructure and are, therefore, rate limiting. In order to pursue a better understanding of the molecular events underlying such slow interconversions, we applied the recently introduced pseudo-proline (⌿Pro) concept as a tool to study the dynamics of Xaa-Pro bonds by determining the kinetics and thermodynamics of cis/trans isomerism. We show that enhanced isomerization rates of tertiary amide bonds prior to a ⌿Pro unit in short model peptides is due to lowered transition state barriers. In addition, pronounced effects upon the dynamics of the reversible transition between helix I and II of oligoprolines containing one or several ⌿Pro units were observed.