Prion Protein Essay

In the subsequent essay I will discuss and explain the relative function of the Prion protein. The Prion protein, also known as PrPC, ‘’is a membrane-anchored protein with two N-glycosylation sites and, although it is highly expressed in the nervous tissues, its physiological functions have yet to be well established’’ (Coordination Chemistry Reviews). PrPC/PrP is found in healthy brains in this form, and consists of 250 Amino Acids, yet after a simple misfolding in the secondary structure; this can alienate the PrP and forms PrPsc, which is the abnormal form of the Prion protein. The infectious agent PrPsc causes neuropathological changes in the brain, and instantly places the individual under the category of someone with the prion disease. PrPsc forms insoluble fibres and thus cannot be studied well using Nuclear Mass Resonance (NMR), and it is also more resistant to protease digestion. Furthermore, ‘’ The transmissible spongiform encephalopathies (TSEs) arise from conversion of the membrane-bound prion protein from PrPC to PrPSc, the latter being the scrapie form. Examples of the TSEs include mad cow disease, chronic wasting disease in deer and elk, scrapie in goats and sheep, and kuru and Creutzfeldt-Jakob disease in humans’’ (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904554/. 2014). The following diagram shows the conversion from PrPc to PrPsc:

As of now, the functional roles of prions remain an enigma, with the exact functional role not being known. There have been several attempts to try and understand the physiological functions of the prion protein. One way of trying to deduce the functions would be to see which other proteins would interact with PrP, and some of the interactors would be key components of physiolo...

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... (CNS) may also indicate another copper binding function for PrP. In blood and blood plasma, amino acids are mainly what copper binds to, yet the chief component which it actively binds to is Serum Albumin, which readily takes up 1 copper at its N terminal. The cerebrospinal fluid however, contains more amino acids and lacks a high quantity of serum albumin, and othe copper binding constituents normally found in blood. Thus it is hypothesised that PrP plays a role similar to albumin, by helping maintain copper homeostasis. Several studies have also shown that PrP opposes apoptosis reactions in some cells, by protecting the cells from the signals which would usually cause apoptosis to occur. Mutagenesis experiments have shown the PrP octarepeat domain is required to protect against Doppel-protein toxicity, which when usually expressed, would bring about cell death.