Scientist Discovers Infectious Proteins That Cause Brain Diseases

Dr. Stanley Prusiner's groundbreaking 1982 paper challenged a 'central dogma' of molecular biology.

Apr. 9, 2026 at 6:03am by Ben Kaplan

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A highly abstract, geometric painting in muted earth tones depicting the complex, interlocking structures and transformative nature of prion proteins, conveying the unseen forces at work in the molecular world.Prusiner's discovery of infectious proteins that defy traditional biological dogma opened up new frontiers in the study of neurodegenerative diseases.San Francisco Today

In 1982, Dr. Stanley Prusiner, a researcher at the University of California, San Francisco, published a paper in the journal Science showing that infectious proteins called 'prions' caused a degenerative nerve disease in sheep. This transformed the scientific understanding of how certain diseases are transmitted, contradicting the prevailing 'central dogma' of molecular biology.

Why it matters

Prusiner's discovery of prions challenged the long-held belief that all infectious diseases were caused by viruses or bacteria. His work paved the way for a new field of study on misfolded proteins and their role in neurodegenerative diseases like Creutzfeldt-Jakob disease (CJD) and Alzheimer's.

The details

Prusiner had been studying the sheep disease scrapie, which had long been a mystery in terms of how it was transmitted. He also recalled a patient he had seen die rapidly of CJD a decade earlier, with no signs of a viral or bacterial infection. Prusiner systematically worked to isolate and identify the 'infectious agent' driving these diseases, ultimately pinpointing a protein as the culprit. He proposed the name 'prion' to describe this infectious protein, which he said could 'code for its own biosynthesis' - a hypothesis that contradicted the 'central dogma' of molecular biology at the time.

  • On April 9, 1982, Prusiner published his groundbreaking paper in the journal Science.
  • In the 1950s, the term 'slow virus' had been coined to describe diseases like scrapie in sheep and goats.
  • By the 1960s, scientists had started applying the 'slow virus' term to certain human disorders like kuru and Creutzfeldt-Jakob disease (CJD).

The players

Dr. Stanley Prusiner

A researcher at the University of California, San Francisco who discovered the existence of prions - infectious proteins that can cause degenerative brain diseases.

Tikvah Alper

A radiobiologist whose team found that the scrapie disease could still be transmitted even when infected tissue was irradiated with UV light, which damages DNA.

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What they’re saying

“At that time, I was beginning a residency in neurology and was most impressed by a disease process that could kill my patient in two months by destroying her brain while her body remained unaffected by this process.”

— Dr. Stanley Prusiner

What’s next

Prusiner's proposal was not widely accepted at first, but over the next 15 years, scientists elucidated the protein structure of prions and showed how they could take multiple conformations and convert healthy proteins into pathological forms. Follow-up work also showed certain genes could predispose people to prion diseases.

The takeaway

Prusiner's groundbreaking discovery of prions as the infectious agent behind certain fatal brain diseases upended the scientific consensus and paved the way for a new field of study on misfolded proteins and neurodegenerative disorders.