|Silva, Christopher - Chris|
|ONISKO, BRUCE - Former ARS Employee|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2009
Publication Date: 9/15/2009
Citation: Silva, C.J., Onisko, B., Dynin, I.A., Erickson, M.L., Carter, J.M. 2009. Mass Spectrometry of Prions: Approaches to Conformational Distinction. [Abstract]. AOAC 123rd Annual Meeting & Exposition. S-902. p68-69
Technical Abstract: Prions are the agents that cause a set of fatal neurological diseases that include Creutzfeldt-Jakob disease. Prions are composed solely of protein. Unlike viral, bacterial, or fungal pathogens, the information necessary to propagate the infection is contained in the conformation of the prion isoform and not in nucleic acids. Prions and their normal cellular isoform have different physicochemical properties. These include: insolubility in non-denaturing detergents, and resistance to partial proteinase K digestion. Ultracentrifugation of properly homogenized prion infected tissue followed by partial digestion with protein K yields preparations that are infectious and highly pure. The infectious prions can be inactivated and then analyzed by mass spectrometry. We exploit ultracentrifugation to isolate infectious prions and analyze them by mass spectrometry. We use a nano LC-MS-MS system to quantitate the prions present in a sample. Our limit of detection is in the attomole range (10 exp -18 mole). Unlike other MS methods, this approach permits the quantitation of viable pathogens. The utility of mass spectrometry in distinguishing among prion strains will be discussed.