Bovine Spongiform Encephalophathy

Bovine Spongiform Encephalophathy

Abstract: Bovine spongiform encephalopathy is caused by a prion, which is an infectious agent comprised solely of protein. The prion is a degenerate form of a normal cellular protein found in the brain and in nervous tissue. It targets the normal protein and causes the normal protein to change its shape. When enough of the prion is produced, the cell dies and symptoms of the disease are expressed.

Bovine spongiform encephalopathy (BSE), more commonly known as mad cow disease, is an unusual disease in regards to the fact that it is not caused by bacteria, viruses, fungi, or any other organism. Instead the disease is caused by prions, infectious agents simply composed of protein. Prions lack nucleic acid and are composed of an abnormal isoform of a normal cellular protein. What this means is that the prions and the cellular proteins have the same arrangements of the amino acids; however, the prion is folded differently from the cellular protein. "They are much like the toy "Transformers" that intrigued little kids in the 1980s. A sphynx could become a robot; a bug could become a warrior. Nothing was added; nothing subtracted."(Ruth Levy Guyer, Ph.D., 1) The tightly wound alpha helixes (figure 2) of the normal cellular proteins are unfolded and turn into beta sheets (figure 1).

(Ruth Levy Guyer, Ph.D., 1)

Figure 1

Figure 2

Another feature of the prion is its ability to remain stable in extreme conditions. Because prions do not have any DNA or RNA like other infectious agents, they are very hard to deal with. Prions are extremely resistant to conventional procedures to inactivate them including irradiation, boiling, dry heat, and chemicals such asformalin, betapropiolactone, and alcohols.

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...is a disease that runs in families and prevents people from sleeping, causes motor and emotional problems, and is eventually a killer. GSS was linked to two mutations in the prion gene in 1989. Prion fragments accumulate in the brain in

structures called plaques. In Alzheimer's disease, similar plaques develop, but they are composed of fragments of a different protein.

Works Cited

“Prion” Wikipedia. 28 July 2006 < http://en.wikipedia.org/wiki/Prion>.

DeArmond, Stephen J., M.D., Ph.D., Safar, Jiri, M.D., Groth, Darlene, A.B., Prusiner, Stanley B., M.D. “Prions” Office of Health and Safety. 28 July 2006 < www.cdc.gov/od/ohs/biosfty/bmbl4/bmbl4s7d.htm>.

Guyer, Ruth Levy, Ph.D. “Prions: Puzzling Infectious Proteins” National Institutes of Health Office of Science. 28 July 2006 < science.education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/prions/prions1.html>.