Summary
Misfolded infectious proteins that convert normal proteins into the abnormal form, causing diseases like scrapie.
In depth
Prions are misfolded versions (PrPSc) rich in beta sheets of a normal brain protein (PrPC); they convert normal copies to the misfolded form and form aggregates. Diseases include Creutzfeldt-Jakob disease, kuru and BSE.
They resist heat, radiation and many disinfectants because they contain no nucleic acid. Stanley Prusiner received the 1997 Nobel Prize for the prion hypothesis.
Prion diseases are rare, progressive and fatal, producing sponge-like holes in the brain. They may be sporadic, inherited (PRNP mutations) or acquired, such as variant CJD caused by eating beef from cattle with BSE, or kuru among the Fore people of Papua New Guinea who practised ritual cannibalism.
Stanley Prusiner proposed the protein-only hypothesis, for which he received the 1997 Nobel Prize. Prions resist heat, radiation and many disinfectants, making sterilising instruments difficult. Yeast prions also exist and may act as heritable switches.
Key idea: prions show that information can be transmitted by protein shape, without any nucleic acid.
Frequently asked questions
What is Prions?
Misfolded infectious proteins that convert normal proteins into the abnormal form, causing diseases like scrapie.
Which area of biology covers Prions, and how advanced is it?
Prions is one of the 51 topics in Biomolecules & Biochemistry. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Primary Structure, Protein Folding and Chaperones, Lipid Rafts.
Can you give an example of Prions?
Kuru spread among the Fore people of Papua New Guinea through funeral rites.
What should I learn before Prions?
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to Prions. Advanced topics assume the Intermediate vocabulary.
What topics are related to Prions?
The closest topics to Prions are Primary Structure, Protein Folding and Chaperones, Lipid Rafts, Ribozymes. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Prions?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Prions. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Prions different from Primary Structure?
Prions: Misfolded infectious proteins that convert normal proteins into the abnormal form, causing diseases like scrapie. Primary Structure: The linear order of amino acids in a polypeptide, which determines all higher levels of folding. Read both side by side and note what each one explains.
How should I study Prions step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Primary Structure and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.