This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Regarding prion protein which of the following statment is true: 
Select and explain. 
A. It is protein product coded in viral DNA, B. It catalyses abnormal folding of other proteins, C. It protect disulfide bonds from oxidation, D. It cleaves normal proteins
B: It catalyses abnormal folding of other proteins
Answer: B: It catalyses abnormal folding of other proteins 
Explanation: Prions propagate by transmitting a misfolded protein state Alteration in the conformation of the protein Normal a-helix structure is conveed to b-sheet structure. Acts as a template to guide the misfolding of more protein into prion form. Aggregations of these abnormal isoforms form highly structured amyloid fibers, This altered structure is extremely stable, insoluble and accumulates in infected tissue Causing tissue damage and cell death