Nanosecond T-jump experiment in poly(glutamic acid): A circular dichroism study

Lucille Mendonça (1) , François Hache (1)

1 LOB - Laboratoire d'optique et biosciences

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.

Mots clés: circular dichroism; poly(glutamic acid); T-jump

Domaines: Optique [physics.optics]

Lucille Mendonça, François Hache. Nanosecond T-jump experiment in poly(glutamic acid): A circular dichroism study. International Journal of Molecular Sciences, 2007, 13 (2), pp.2239-2248. ⟨10.3390/ijms13022239⟩. ⟨hal-00324327⟩