Comparative study of the folding/unfolding dynamics of poly(glutamic acid) in light and heavy water.
The folding/unfolding equilibrium is investigated in poly(glutamic acid) (PGA) by two complementary sets of experiments: temperature-dependent steady-state circular dichroism spectra on the one hand and time-resolved circular dichroism measurements coupled with a T-jump experiment on the other hand. The experiments are performed for PGA dissolved in water for various pH values, as well as in heavy water. The kinetic and thermodynamic parameters extracted from these measurements are shown to be markedly different between light and heavy water, which is assigned to the difference in hydrogen bond energies in both solvents.
Laboratoire d'Optique et Biosciences, École Polytechnique, CNRS, INSERM 91128 Palaiseau cedex, France.
Lucille
L
Mendonça
Andreas
A
Steinbacher
Raphaël
R
Bouganne
François
F
Hache
D002942:Circular Dichroism; D017666:Deuterium Oxide / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011099:Polyglutamic Acid / Q000737:chemistry*; D017510:Protein Folding; D058767:Protein Unfolding; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
D014867:Water; D011099:Polyglutamic Acid; D017666:Deuterium Oxide