BIOCHEMISTRY AND PATHOBIOCHEMISTRY OF PRI ON PROTEINS AND BSE

Prion proteins (PrP) occur in a high concentration in neurons of prima tes, ruminants and rodents and are of importance for the stability and regulation of excitability. The genes for the PrP are composed of abo ut 750 nucleotide pairs and exist in different variants. At a certain sequence of amino acids in different positions of the PrP there is a t endency for instability. By a change of the structure stable, protease -resistent molecules (PrPRES) develop, that connect to complexes (fibr ills, amyloid). In the cells, PrPRES induce transformation of the PrP into the stable form, that accumulates in the neurons and causes degen eration. The number of neurons diminishes and that of glia cells incre ases. In sheep scrapie develops. Intake of PrPRES by meat meal of infe cted sheep effects the development of bovine spongiform encephalopathy .