title: Mechanically induced helix-coil transition in biopolymer networks.
abstract: The quasi-equilibrium evolution of the helical fraction occurring in a biopolymer network (gelatin gel) under an applied stress has been investigated by observing modulation in its optical activity. Its variation with the imposed chain extension is distinctly nonmonotonic and corresponds to the transition of initially coiled strands to induced left-handed helices. The experimental results are in qualitative agreement with theoretical predictions of helices induced on chain extension. This new effect of mechanically stimulated helix-coil transition has been studied further as a function of the elastic properties of the polymer network: crosslink density and network aging.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Courty
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Gornall
authors.forename: Eugene M
authors.initials: EM
authors.lastname: Terentjev
mesh_terms: D000595:Amino Acid Sequence; D016880:Anisotropy; D001703:Biophysics / Q000379:methods*; D001704:Biopolymers / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D019855:Ethylene Glycol / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry; D006860:Hydrogen Bonding; D008027:Light; D008958:Models, Molecular; D015233:Models, Statistical; D008962:Models, Theoretical; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D001704:Biopolymers; D005780:Gelatin; D019855:Ethylene Glycol