Biomolecular kinetics and dynamics through IR spectroscopy and rapid mixing, intrinsically disordered proteins

Date: 
Thursday, January 29, 2015 - 2:00pm to Friday, January 30, 2015 - 10:00am
Speaker: 
Steven Waldauer
Speaker's Institution: 
University of Zurich

Research Interests

Biomolecular kinetics and dynamics through IR spectroscopy and rapid mixing, intrinsically disordered proteins 

Seminars

Thursday, January 29, 2pm, 331 Klamath Hall: Research Seminar - "Exploring Light-Activated Dynamics in Solar Cell and Photo-Catalytic Materials"

Friday, January 30, 9am, 217 LISB: Future Research Workshop

Title and Abstract

"Investigating allosteric dynamics through a photo-controllable protein and ultrafast IR spectroscopy"

Allostery can be described as a process in which a perturbation at one site on a protein, such as ligand binding or covalent modification, leads to changes in activity or binding at a distal site. Although allostery is well recognized as an increasingly important property of a wide variety of proteins integral for life processes, the atomistic mechanism describing communication between sites is still a topic of much debate. In this work, the conformational dynamics that may underlie allosteric mechanisms are investigated through a modified photo-controllable protein and pump-probe IR spectroscopy. The relaxation of the protein binding groove in response to a small perturbation was found to be highly nonexponential and indicative of a complex free energy landscape. To further investigate the roles of internal and external friction, solvent viscosity dependent experiments in parallel with molecular dynamics simulations were performed. Although the observed pronounced viscosity dependence can be best fit to a power law, hinting at fractional viscosity dependence, viscogen dependent measurements provide strong evidence that direct interactions play a role as well.

Select Publications

Waldauer SA, Stucki-Buchli B, Frey L, Hamm P, "Effect of viscogens on the kinetic response of a photoperturbed allosteric protein,” J. Chem. Phys. 141 , 22D514 (2014).

Buchli, B*, Waldauer, SA*, Walser R.*, Donten ML, Pfister R, Blochliger N, Steiner, S, Cafilsch A, Zerbe O, Hamm P., “Kinetic response of a photoperturbed allosteric protein,” Proc. Natl. Acad. Sci. USA 110, 11725 (2013). 

Waldauer SA, Bakajin O, Lapidus LJ, “Extremely slow diffusion in unfolded protein L” Proc. Natl. Acad. Sci USA 107, 13713 (2010).