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Characterization and enzymatic degradation of Sup35NM, a yeast prion‐like protein
Author(s) -
Chen ChingYing,
Rojanatavorn Kawan,
Clark A. Clay,
Shih Jason C.H.
Publication year - 2005
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.041234405
Subject(s) - yeast , enzyme , chemistry , biochemistry , prion protein , degradation (telecommunications) , characterization (materials science) , computational biology , biology , computer science , nanotechnology , medicine , materials science , disease , pathology , telecommunications
Transmissible spongiform encephalopathies (TSEs) are believed to be caused by an unconventional infectious agent, the prion protein. The pathogenic and infectious form of prion protein, PrP Sc , is able to aggregate and form amyloid fibrils, very stable and resistant to most disinfecting processes and common proteases. Under specific conditions, PrP Sc in bovine spongiform encephalopathy (BSE) brain tissue was found degradable by a bacterial keratinase and some other proteases. Since this disease‐causing prion is infectious and dangerous to work with, a model or surrogate protein that is safe is needed for the in vitro degradation study. Here a nonpathogenic yeast prion‐like protein, Sup35NM, cloned and overexpressed in E. coli , was purified and characterized for this purpose. Aggregation and deaggregation of Sup35NM were examined by electron microscopy, gel electrophoresis, Congo red binding, fluorescence, and Western blotting. The degradation of Sup35NM aggregates by keratinase and proteinase K under various conditions was studied and compared. These results will be of value in understanding the mechanism and optimization of the degradation process.