title: Nanosecond T-jump experiment in poly(glutamic acid): a circular dichroism study.
abstract: Poly(glutamic acid) has been studied with a nanosecond T-jump experiment. A new experimental set-up based on the frequency-quadrupling of an 82 MHz Titanium-Sapphire laser allows rapid CD measurements to be performed. Combining time-resolved absorption and circular dichroism at 204 and 220 nm, we are able to measure precisely the unfolding relaxation time as well as the helical fraction evolution. We show that only CD at 220 nm is relevant to observe the unfolding of an alpha helix whereas no change is observed for CD at 204 nm. Conversely, both absorptions yield information on the dynamics of the process.
authors.affiliation: Laboratory for Optics and Biosciences, Ecole Polytechnique/CNRS/INSERM, 91128 Palaiseau cedex, France.
authors.forename: Lucille
authors.initials: L
authors.lastname: Mendonça
authors.affiliation: Laboratory for Optics and Biosciences, Ecole Polytechnique/CNRS/INSERM, 91128 Palaiseau cedex, France.
authors.forename: François
authors.initials: F
authors.lastname: Hache
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002942:Circular Dichroism / Q000379:methods*; D018698:Glutamic Acid / Q000737:chemistry*; D007700:Kinetics; D007834:Lasers; D011108:Polymers / Q000737:chemistry; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014025:Titanium / Q000737:chemistry
chemical_list: D011108:Polymers; D018698:Glutamic Acid; D014025:Titanium; D000537:Aluminum Oxide