Prions Flashcards

Flashcards about Prions, their structure, diseases, and characteristics, based on lecture notes.

Prion

Proteinaceous infectious particle responsible for neurodegenerative diseases; consists only of protein, lacking nucleic acid genome.

Conformational Change

Alteration in protein shape leading to gain of toxic activity, aggregation, or loss of biological function.

Scrapie

A prion disease that first appeared in the 1930s.

Kuru

A prion disease with an outbreak in the 1950s that was eventually transmitted to chimpanzees by scientists.

Creutzfeldt-Jakob Disease (CJD)

A neurodegenerative disease in humans caused by prions, leading to loss of cognitive and motor abilities; can be acquired from contaminated surgical instruments or prion-containing growth hormone.

Mad Cow Disease (BSE)

Bovine spongiform encephalopathy; an outbreak in 1986, linked to a new variant of CJD in humans through contaminated British beef.

Prion Gene

Identified in 1985; encodes a normal form of prion protein produced by uninfected people.

Stanley Prusiner

Coined the term 'prion' in 1982; won the Nobel Prize in 1997 for his work on prions.

Prion Cause

Caused by abnormal proteins that are not killed by standard methods for sterilizing surgical equipment.

Prion Consequences

Leads to loss of thinking and movement abilities, memory loss, brain shrinkage, and sponge-like lesions; usually fatal within one year.

Prion Hypothesis

The theory that infectious agents causing diseases consist only of protein, lacking nucleic acids, resistant to UV radiation but susceptible to protein-disrupting substances.

PrPC

Normal cellular prion protein found in the membranes of normal cells.

PrPSc

Scrapie form of prion protein; results from protein misfolding and can arise by mutation or exogenous sources.

Prion Structure

Normal PrP: mostly alpha-helical; Pathogenic PrPSc: higher beta-sheet content.

Transmissible Spongiform Encephalopathies

A group of diseases caused by prions, including scrapie in sheep and bovine spongiform encephalopathy (BSE) in cows.

Prion Resistance

Highly resistant to conventional physical decontamination methods, disinfectants, heat, UV radiation, ionizing radiation, and formalin.

Bovine Spongiform Encephalopathy (BSE)

A progressive neurological disorder of cattle resulting from infection by a prion.

Prion Misfolding

Misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein.

Prion Protein (PrP)

Found throughout the body, differs in structure in infectious material, resistant to proteases.

Alzheimer's Disease and Prions

Polymorphism in the Prnp gene is a risk factor. PrP binds to amyloid-ẞ (AB) peptides, leading to misfolding and amyloid plaques.

Heterodimer Model of Prion Propagation

Assumes a single PrPSc molecule binds to a single PrPC molecule, catalyzing its conversion into PrPSc.

Fibril Model of Prion Propagation

Assumes PrPSc exists only as fibrils, fibril ends bind PrPC and convert it into PrPSc.

Prion vs Virus

Prion: Infectious protein particle lacking nucleic acid. Virus: Infective agent consisting of nucleic acid in a protein coat.