(191da) Light-Controlled Protein Dynamics Observed with Neutron Spin Echo Measurements | AIChE

(191da) Light-Controlled Protein Dynamics Observed with Neutron Spin Echo Measurements

Authors 

Wang, Y. - Presenter, University of Southern california
The photoresponsive interaction of light-sensitive azobenzene surfactants with Ribonuclease-A at neutral pH has been investigated as a means to control protein structure change with light illumination. This cationic azobenzene surfactant, azoTAB, which undergoes a reversible photo isomerization upon exposure
to the appropriate wavelength of light, adopts a relatively hydrophobic, trans structure
under visible light illumination and a relatively hydrophilic cis structure under UV
light illumination. Small-angle neutron scattering (SANS) and neutron spin echo
(NSE) spectroscopy were used to measure the detailed structure and internal
dynamics of ribonuclease A in the presence of the photosurfactant, respectively. SANS data shows that ribonuclease A is unfolded little by little with increasing concentration of azoTAB. And we use three different models, which are rigid bond, soft linker, and freely jointed to describe the protein structure change during the process. In addition, the internal dynamic motions were measured using NSE technology, and the result of which matches well with our three different models. Combined, these results provide insight into a unique light-based method of controlling protein structure and dynamics.