ARS | Publication request: Guanidinium Chloride Unfolding of PrP**Sc Exhibits Marked Differences Between Genotypes

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 2009
Publication Date: September 23, 2009
Citation: Nicholson, E.M., Greenlee, J.J., Kunkle, R.A., Hamir, A.N. 2009. Guanidinium Chloride Unfolding of PrP**Sc Exhibits Marked Differences Between Genotypes [abstract]. Prion 2009. p. 182.

Technical Abstract: Background: Various methods have been promoted as to their potential to differentiate TSE isolates (strains). Traditionally a panel of inbred mice has been used to differentiate TSE isolates, and while this approach has proven rigorous it is slow. Biochemical methods employed to date are rapid in comparison but for the most part are limited to proteinase K cleavage point differentiation as determined by the molecular weight of the protein on a Western blot. This approach is used extensively with BSE and has been employed by various groups to reliably differentiate H-type, L-type, and classical BSE. In the context of the protein only hypothesis, the differences must arise due to different folding parameters (structure, stability, or both). It is not surprising then that denaturant unfolding of PrP**Sc monitored by circular dichroism has been used to differentiate various TSE isolates. Methods: Here we adapt denaturant unfolding of PrP**Sc to be monitored by a commercial, ELISA based diagnostic platform. Results and Discussion: Marked differences in denaturant unfolding parameters are observed between sheep of different genotypes inoculated with a single sheep scrapie isolate. This result highlights the difficulty of adapting approaches developed for rodent models of TSEs to a natural host system as well as the potential for passage in a new host of different genotype to drive strain differentiation.