Research with the biochemist Bolton enabled Prusiner to discover and characterize the specific protein causing prion disease. This paper was dated December 24, 1982.

Nearly simultaneously, Prusiner and the same co-authors published an additional, longer paper dated December 21, 1982, further characterizing the pure protein of the infectious agent:

"Further purification and characterization of Scrapie prions," Biochemistry, 21 (1982) 6942-6950. 

These papers provided the necessary evidence to convince members of the scientific community, and eventually led to Prusiner's Nobel Prize.

(Thanks to Juan Weiss for these references and their interpretation.)