title: Proteolysis of abnormal prion protein with a thermostable protease from Thermococcus kodakarensis KOD1.
abstract: The abnormal prion protein (scrapie-associated prion protein, PrP(Sc)) is considered to be included in the group of infectious agents of transmissible spongiform encephalopathies. Since PrP(Sc) is highly resistant to normal sterilization procedures, the decontamination of PrP(Sc) is a significant public health issue. In the present study, a hyperthermostable protease, Tk-subtilisin, was used to degrade PrP(Sc). Although PrP(Sc) is known to be resistant toward proteolytic enzymes, Tk-subtilisin was able to degrade PrP(Sc) under extreme conditions. The level of PrP(Sc) in brain homogenates was found to decrease significantly in vitro following Tk-subtilisin treatment at 100 °C, whereas some protease-resistant fractions remain after proteinase K treatment. Rather small amounts of Tk-subtilisin (0.3 U) were required to degrade PrP(Sc) at 100 °C and pH 8.0. In addition, Tk-subtilisin was observed to degrade PrP(Sc) in the presence of sodium dodecyl sulfate or other industrial surfactants. Although several proteases degrading PrP(Sc) have been reported, practical decontamination procedures using enzymes are not available. This report aims to provide basic information for the practical use of a proteolytic enzyme for PrP(Sc) degradation.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan, kogay@mls.eng.osaka-u.ac.jp.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Koga
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Akikazu
authors.initials: A
authors.lastname: Sakudo
authors.forename: Minoru
authors.initials: M
authors.lastname: Tobiume
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Aranishi
authors.forename: Azumi
authors.initials: A
authors.lastname: Hirata
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Takano
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ikuta
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kanaya
mesh_terms: D003902:Detergents / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D018620:PrPSc Proteins / Q000378:metabolism*; D059748:Proteolysis; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism; D020860:Subtilisin / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D019712:Thermococcus / Q000201:enzymology*
chemical_list: D003902:Detergents; D004791:Enzyme Inhibitors; D018620:PrPSc Proteins; D012967:Sodium Dodecyl Sulfate; D020860:Subtilisin