This study is intended to develop novel medical cleaning agents that can remove abnormal prion from medical instruments. The difficulty in inactivation of contaminated abnormal prion on medical instruments, which causes iatrogenic secondary infection of transmissible spongiform encephalopathy (TSE), is a problem at clinical front. Tk-subtilisin, a highly stable protease isolated from a hyperthermophile, can maintain its proteolytic activity under protein-denaturing conditions, such as high temperature. Our previous work revealed that this protease can degrade abnormal prion to a level undetectable by western-blot analysis. Furthermore, we also found that the Tk-subtilisin can degrade proteins in the presence of surfactants and that can be produced in large scale. Therefore, it is a promising enzyme that can be developed as a detergent additive to decrease the secondary infection risk of TSE.
The novel detergents inactivate abnormal prion contaminated in medical instruments without special equipments, much easier than conventional inactivation processes. Furthermore, they can provide a method to inactivate abnormal prion on endoscopes by which conventional inactivation methods cannot be employed because of the poor resistance of endoscopes against inactivation reagents. This technology can decrease the risk of the iatrogenic secondary infection of TSE.
