Recent studies of prions have led to new approaches in treating fatal illnesses such as Creutzfeld-Jakob disease. Dr Greig Milsom, r&d manager, and Dr Adam Nadany, senior chemist, Endeavour Speciality Chemicals, explain the technologies involved.
Prion diseases entered the public consciousness in the 1980s, when the bovine spongiform encephalopathy (BSE) epidemic swept through the UK’s cattle herds. New variant Creutzfeld-Jakob disease, or vCJD, started to appear in the human population, with many of the sufferers believed to have eaten infected beef containing nervous system tissue. It remains incurable.
It was some time before the cause of BSE was identified. Uniquely for an infectious disease it is not caused by an organism such as a bacterium, virus or fungus, but by a protein. Despite the absence of genetic material, these misfolded proteins (prions), termed PrPSc after scrapie, the transmissible spongiform encephalopathy they were first identified in, are transmissible by causing normal proteins to misfold too. This sets off a chain reaction, where these normal PrPc proteins refold to a structure with significantly greater beta-sheet content. The resulting PrPSc prions then combine to form fibrils, which can split in two, further accelerating the course of the disease.
The misfolded prions aggregate into amyloid plaques and accumulate within neuronal tissue; and the brain develops a characteristic spongiform structure. The patient develops neurological symptoms such as dementia and ataxia and, eventually, death results. While the incubation period runs into years, once the disease takes hold patients deteriorate very rapidly. The structure of the misfolded prion itself is very stable, which makes denaturing difficult, and hence they are not easy to remove from the environment.
Not yet a Subscriber?
This is a small extract of the full article which is available ONLY to premium content subscribers. Click below to get premium content on Manufacturing Chemist.
Subscribe now Already a subscriber? Sign in here.