BIOL 55 |
| In vivo conversion of cellular prion protein PrPC to its abnormal pathogenic isoform (PrPres) is associated with conformational transition of α-helices to β-sheets. Protein misfolding cyclic amplification (PMCA) probably closely mimics this conversion in vitro. This technique involves sonication and incubation of PrPC with trace amounts of PrPres, but very little is known about the mechanism. We have observed that hamster PrPC undergoes structural changes on ultrasonic treatment, in the absence of seeding with PrPres. Assayed by Western blot after native gel electrophoresis or native ELISA, PrPC concentration decreases as a function of sonication time. However, by Western after denaturing SDS-PAGE, the concentration of PrPC does not change. This suggests the presence of a third stable PrP conformer, which may be intermediate in the conversion of PrPC to PrPres by PMCA. The new conformer undergoes conversion to PrPres by PMCA more readily than PrPC. |
|
Protein Structure and Folding
4:30 PM-6:30 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Biological Chemistry |