A 66-year-old woman vocalist complains of difficulty remembering her favorite songs. This problem continues to worsen over the next several months, and the patient becomes increasingly withdrawn from her family. When examined, she evidences dementia and gait disturbance. MRI demonstrates mild cerebral atrophy. Analysis of CSF shows no inflammatory cells and normal levels of glucose and protein. An electroencephalogram reveals periodic spike-wave complexes. One month later, the patient is bedridden and nonresponsive, and subsequently dies. The brain biopsy shows spongiform degeneration of the gray matter, characterized by individual and clustered vacuoles, with no evidence of inflammation.
1) What is the most likely disease?  (Creutzfeldt-Jakob disease (CJD))
2) What is the most likely organ-specific amyloidosis in the patient? (APrP)
3) What key feature distinguishes normal proteins from their
pathologic forms in the brain of the patient? (Three-dimensional conformation)