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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #313640

Research Project: Immunodiagnostics to Detect Prions and Other Important Animal Pathogens

Location: Produce Safety and Microbiology Research

Title: Using proteinase K to study the structure of prions.

Author
item Silva, Christopher - Chris
item VAZQUEZ-FERNANDEZ, ESTER - University Of Alberta
item REQUENA, JESUS - University Of Santiago De Compostela

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/30/2015
Publication Date: 5/1/2015
Publication URL: http://www.tandfonline.com/doi/pdf/10.1080/19336896.2015.1033248
Citation: Silva, C.J., Vazquez-Fernandez, E., Requena, J.R. 2015. Using proteinase K to study the structure of prions.. Meeting Abstract. Prion (Supplement 1) 9: S69-S70.

Interpretive Summary:

Technical Abstract: Background/Introduction. The secondary structure of prions is composed almost entirely of '-sheet secondary structure. Structural constraints suggest that the '-sheet secondary structure is arranged in a '-solenoid. The '-sheet secondary structure is thought to be responsible for the remarkable resistance prions have to proteinase K (PK) digestion. A detailed analysis of the PK digestion products can be used to study the structure of prions by identifying the location of PK cleavage sites in wild type and GPI-anchorless prions. Materials and Methods. Mass spectrometry and antibodies were used to identify PK cleavage sites in PrPSc. The PK cleavage sites (from 23-160) in the wild type 263K and drowsy strains of hamster adapted scrapie were identified. In addition murine-adapted GPI-anchorless prions were digested with PK and analyzed by mass spectrometry to determine the PK cleavage sites throughout the entire protein. Antibody-based analysis was performed by other researchers to determine the PK cleavage sites in human and hamster prions. Results and Conclusions. The results of these diverse analyses were used to identify the regions of the prion that were accessible to PK digestion. These regions were presumed to be accessible to PK due to flexible stretches connecting the ß-strand components in PrPSc. These data, combined with physical constraints imposed by spectroscopic results, were used to propose a qualitative model for the structure of PrPSc. Assuming that PrPSc is a four rung ß-solenoid, we have threaded the PrP sequence to satisfy the PK proteolysis data and other experimental constraints.