Additivity in the helix-coil transition of alpha-helical peptides with varying length

Abstract

The mechanical unfolding of alanine-rich helices with various lengths and sequences has been characterized using Adaptive Steered Molecular Dynamics (ASMD). We have found that the potential of mean force (PMF) and hydrogen bonding profiles for these various helices exhibit a correspondence between different chains, and the required energetics for the overall unfolding process is additive with respect to the chain length. [Biophys. J, 120, 2009 (2021)] Polyalanine peptides were used to guide the hypotheses because of their high helix propensity for helical formation, and the low computational cost needed to simulate them.