University of Minnesota
School of Physics & Astronomy

Biophysics Seminar

Thursday, February 2nd 2017
11:15 am:
Biophysics Seminar in 120 PAN
Speaker: David Punihaole, University of Minnesota, Department of Chemistry
Subject: UV Resonance Raman Spectroscopy: A New Tool to Probe Amyloid-like Fibril Structures

There is currently little that is known about the structure of polyglutamine (polyQ) fibrils, which are involved in at least ten neurodegenerative diseases, including Huntington’s. Given their insoluble and non-crystalline nature, new and incisive biophysical methods need to be developed in order to obtain high-resolution structural information of polyQ and other amyloid-like fibrils. Here, we present our recent advances in UV resonance Raman (UVRR) spectroscopy that enable the elucidation of molecular-level structural information of amyloid-like fibrils. We show, for example, how the primary amide UVRR bands report on the local hydrogen bonding and dielectric environment of glutamine side chains. We also discuss a newly discovered spectroscopic marker, the Amide IIIP vibration, which sensitively reports on the side chain structure of glutamine. These and other spectroscopic markers are used to gain insights into the peptide backbone and side chain conformations of polyQ peptides in solution-state and in fibrils. Finally, we demonstrate how the structural information obtained from UVRR can be utilized to guide Molecular Dynamics simulations in order to obtain experimentally validated structural models of polyQ fibrils.

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