PRIONS: INFECTIOUS PROTEINS REPSONSIBLE FOR MAD COW DISEASE - By Megan Simmer (August 2003) Fonte: http://www.scq.ubc.ca/prions-infectious-proteins-repsonsible-for-mad-cow-disease/ Prions and prion diseases have been widely discussed in the media in recent years. The interest in prions and prion diseases was stimulated by the outbreak of bovine spongiform encephalopathy (BSE or Mad Cow Disease) in Europe in the mid-nineteen-nineties. This is a relatively new area of study. What exactly has been discovered about prions and prion diseases? What Are Prions? Prions are proteins found on the plasma membrane (the membrane that surrounds a cell and defines its physical boundary). In mammals, prions are found in the highest concentration in cells of the central nervous system. In mammals and yeast, there are several genes coding for different prions. The function of normal prions (denoted PrPC) is unknown. Aberrant or mutant prions (denoted PrPSc) are thought to be the causative agents of a set of neurological…