Helix vs. Sheet Formation in a Small Peptide

Abstract

Segments with the amino acid sequence EKAYLRT appear in natural occurring proteins both in $\alpha$-helices and $\beta$-sheets. For this reason, we have use this peptide to study how secondary structure formation in proteins depends on the local environment. Our data rely on multicanonical Monte Carlo simulations where the interactions among all atoms are taken into account. Results in gas phase are compared with that in an implicit solvent. We find that both in gas phase and solvated EKAYLRT forms an $\alpha$-helix when not interacting with other molecules. However, in the vicinity of a $\beta$-strand, the peptide forms a $\beta$-strand. Because of this change in secondary structure our peptide may provide a simple model for the $\alpha \to \beta$ transition that is supposedly related to the outbreak of Prion diseases and similar illnesses.

to appear in Physical Review E

References in corpus (5)

• Finite-size scaling of helix-coil transitions in poly-alanine studied by multicanonical simulations
• Partition Function Zeros and Finite Size Scaling of Helix-Coil Transitions in a Polypeptide
• Solution effects and the order of the helix-coil transition in polyalanine
• Solvation model dependency of helix-coil transition in polyalanine
• Helix Formation and Folding in an Artificial Peptide