Question

Which of the following statements are true?
A) Prions are modified hydrophobic glycoproteins, which are resistant to proteases.
B) Prions are the smallest proteinaceous infectious agents.
C) Prions are not affected by nucleases, high temperature (up to 80 degrees Celsius) and UV radiations. They are inactivated by diethylpyrocarbonate.
D) All of the above.

Answer 1

Hint: The prions are virus-like particles that do not contain any DNA or RNA. They cause several fatal neurodegenerative diseases in both humans and animals. They are generally resistant to temperature, chemicals and radiation.

Complete answer:
Prions are the glycosylated proteins that cause several neurodegenerative fatal diseases to both animals and human beings. The glycoproteins are the proteins in which the glycans are attached to the amino acid chain. They form bonds with the help of the process called glycosylation. They are regarded as the smallest infectious particles. These proteins are resistant to proteolytic enzymes like proteases. The prions can spread through body fluids like saliva, semen, blood, urine or through direct contact and also through contaminated soil, food or water.

The prion infection leads to abnormal misfolding of once normally folded protein present in the brain. The infectious form of prion has a high content of beta-pleated sheet which results in the formation of an amyloid fibrillous structure that is not present in normal conditions. This fibrillous form makes it resistant to high temperatures, radiations like UV rays but it is can be denatured with the help of diethyl pyro carbonate. It leads to the modification of the structure of the prions.

Therefore the correct answer is option ‘A’.

Note: Some of the proteins present in the fungus show prion kind of activity. The most common disease caused by prion is Creutzfeldt–Jakob disease (CJD) in human beings. It is a highly degenerative neural disease that affects memory, coordination, behavioural and visual changes.