Solid-state NMR Investigations on Protein-Solvent Interactions and Functional Amyloid Proteins

Event Date: 

Thursday, April 12, 2012 - 12:30pm

Event Location: 

  • Room 1008 Bldg 937

Event Contact: 

Speaker:

Ansgar B Siemer - Zilkha Neurogenetic Institute, Keck School of Medicine of USC

Solid-state NMR is a powerful technique for investigating the interaction of proteins with their solvent, which is important for their structure, dynamics, and function. I will present solidstate NMR data on an ice-binding type III antifreeze protein (AFP III) that are contrasted with data on the non-ice binding protein ubiquitin. We identified the ice-binding surface of AFP III and confirmed its direct contact to ice. Furthermore, we investigate the remaining hydration shell of AFP III and the hydration shell of ubiquitin. Frozen solution NMR is an interesting technique in biomolecular NMR especially if it is combined with DNP. However, the linewidth of many proteins in frozen solution at low temperatures commonly used for DNP is relatively broad. I will present data that interrogate the importance of the protein-solvent glass transition for the linewidth of a protein in frozen solution.

Amyloid forming proteins are responsible for neurodegenerative diseases such as Alzheimer and Parkinsons disease. However, there are also proteins that have a beneficial function in their aggregated amyloid conformation. I will present structural data on several amyloids that have functions in programmed cell death phenomena and in long-term memory. Using solidstate NMR in combination with other methods, we are able to learn a lot about the structure and dynamical heterogeneity of these fascinating proteins.