Prions are misfolded proteins that can transmit their misfolded shape to normal variants of the same protein. They are the smallest known infectious agents, contain no genetic material, and have been implicated in diseases like mad cow disease. Prions multiply by converting normal proteins into additional misfolded versions, causing them to accumulate in neurons and not break down. This progressive neuron destruction leaves the brain tissue filled with holes in a spongelike pattern.

1. Prion :
Presented by : Khushbu’ Microbiology

2.  DEFINATION : Misfolded proteins with the ability to transmit their misfolded shape
onto normal variants of the same protein.
 Pronunciation : ˈpriːɒn/ (listen), /ˈpraɪɒn/
 Prion : derives from "proteinaceous infectious particle
 Protein as an infectious agent stands in contrast to all other known infectious agents
such as viruses, bacteria, fungi & parasites all of which contain DNA , RNA or both.

3. Heterodimer model of
prion propagation

5. KEY FEATURES OF PIRONS
 Even smaller than viruses
 (pronounced “pree-ons”)
 simplest infectious agents.
 Like viruses they are obligate parasites,
 no genetic material.
 Although prions are merely self-perpetuating proteins, they have been
implicated as the cause of various diseases including bovine spongiform
encephalopathy (mad cow disease)
 suspected of playing a role in a number of other disorders.

6. PRION :PROPERTIES
 Prion : proteins multiply
 Not broken down by proteases and instead accumulate
within neurons,destroying them.
 Progressive neuron destruction eventually causes
brain tissue to become filled with holes in a spongelike, or
spongiform, pattern.

7. Prion :
Pathogenic type of misfolded protein

8. THANKS