The importance of the disulfide bond in prion protein conversion.
The conversion of normal, protease sensitive prion protein (PrP-sen) to the abnormal protease-resistant form (PrP-res) is of central importance in the pathogenesis of scrapie and other transmissible spongiform encephalopathies. In the present study, the effects of reduction of the disulfide bond on the PrP-sen to PrP-res conversion in a cell-free system were examined. The addition of the disulfide reducing agent dithiothreitol inhibited the cell-free conversion reaction with an IC50 of 2-2.5 mM. Separate pretreatment of either PrP-sen or PrP-res with dithiothreitol and an alkylating agent also inhibited the conversion reaction. Results of this study show that preservation of the disulfide bond is important in the conversion of PrP-sen to PrP-res.
National Institute of Health, National Institute of Allergy and Infectious Disease, Rocky Mountain Laboratories, Laboratory of Persistent Viral Diseases, Hamilton, MT 59840, USA.
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LM
Herrmann
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Caughey
D000478:Alkylation; D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry; D001345:Autoradiography; D002474:Cell-Free System; D006224:Cricetinae; D004220:Disulfides / Q000737:chemistry; D004227:Dithionite / Q000737:chemistry; D004229:Dithiothreitol / Q000737:chemistry; D019286:Endopeptidase K / Q000737:chemistry; D008647:Mesocricetus; D011328:Prions / Q000737:chemistry*; D011487:Protein Conformation; D019163:Reducing Agents / Q000737:chemistry; D013439:Sulfhydryl Reagents / Q000737:chemistry
D004220:Disulfides; D011328:Prions; D019163:Reducing Agents; D013439:Sulfhydryl Reagents; D004227:Dithionite; D019286:Endopeptidase K; D001205:Ascorbic Acid; D004229:Dithiothreitol