On the Extension Behavior of Helicogenic Polypeptides

Abstract

The force laws governing the extension behavior of homopolypeptides are obtained from a phenomenological free energy capable of describing the helix-coil transition. Just above the melting temperature of the free chains, T*, the plot of force, f, vs. end-to-end distance, R, exhibits two plateaus associated with coexistence of helical and coil domains. The lower plateau is due to tension induced onset of helix-coil transition. The higher plateau corresponds to the melting of the helices by overextension. Just below T* the f-R plot exhibits only the upper plateau. The f-R plots, the helical fraction, the number of domains and their polydispersity are calculated for two models: In one the helical domains are viewed as rigid rods while in the second they are treated as worm like chains.

18 pages, 10 figures, to be published in Macromolecules

Cited by in corpus (8)

• Helical structures from an isotropic homopolymer model
• The Effects of Stacking on the Configurations and Elasticity of Single Stranded Nucleic Acids
• Mechanically induced helix-coil transition in biopolymer networks
• Stretching of a single-stranded DNA: Evidence for structural transition
• The nonlinear elasticity of an $\alpha$-helical polypeptide
• Competition for hydrogen bond formation in the helix-coil transition and protein folding
• Stretching force dependent transitions in single stranded DNA
• Glass-like dynamics of the strain-induced coil/helix transition on a permanent polymer network