Creutzfeldt-Jakob disease prion proteins in human brains.

Creutzfeldt-Jakob disease is caused by a slow infectious pathogen, or prion. We found that purified fractions from the brains of two patients with Creutzfeldt-Jakob disease contained protease-resistant proteins ranging in apparent molecular weight from 10,000 to 50,000. These proteins reacted with antibodies raised against the scrapie prion protein PrP 27-30. Rod-shaped particles were found in the brain tissue of the patients that were similar to those isolated from rodents with either scrapie or experimental Creutzfeldt-Jakob disease. After being stained with Congo red dye, the protein polymers from patients with Creutzfeldt-Jakob disease exhibited green birefringence when examined under polarized light. Our findings suggest that the amyloid plaques found in the brains of patients with Creutzfeldt-Jakob disease may be composed of paracrystalline arrays of prions similar to those in prion diseases in laboratory animals.