The relevance of protein dynamics for light-signal sensation and protein folding

by Andreas Stadler (FZ Jülich)

Monday 6 May 2019, 14:30 → 15:30 Europe/Berlin

HS 3 (Physics Department)

The ability to respond to various environmental stimuli is a crucial ability of biological organisms. Light signal sensation and transduction, for instance, are important biological processes that allow organisms to respond to external stimuli. In recent work we have investigated structural and dynamical changes of a light-sensitive photoreceptor protein in response to light-illumination (1,2). In my presentation, I will present recent neutron spectroscopy and small-angle scattering experiments, and I will demonstrate how molecular dynamics and protein flexibility are required for light signal transduction of that photoreceptor. In particular, we could demonstrate that end regions of the photoreceptor protein change flexibility as response to light illumination. Hence, changes of protein flexibility are needed for light signal transduction of a biotechnologically relevant class of proteins.

 

In the second part of my talk I will speak about an experimental study of molecular dynamics of folded and unfolded bovine serum albumin (BSA) (3,4). By using quasielastic incoherent neutron spectroscopy and neutron spin-echo spectroscopy combined with small-angle neutron scattering, we were able to investigate native BSA as well as denatured BSA in different solution states. Polymer-like properties of the unfolded BSA have been observed both in the structure as well as in the dynamics in response to variation of the solvent condition. Molecular dynamics of native BSA, on the other hand, show a clearly distinct dynamic behaviour due to the folded state of the protein.

 

1. Röllen et al. 2018, PLOS ONE 13(7): e0200746.

2. Stadler et al. 2016, Biophysical Journal 110(5), 1064–1074

3. Ameseder et al. 2018, Physical Chemistry Chemical Physics 20 (7), 5128-5139

4. Ameseder et al. 2018, The Journal of Physical Chemistry Letters 9, 2469-2473