Biochemie und pathobiochemie der prionproteine und BSE

Abstract

Prion proteins (PrP) occur in a high concentration in neurons of primates, ruminants and rodents and are of importance for the stability and regulation of excitability. The genes for the PrP are composed of about 750 nucleotide pairs and exist in different variants. At a certain sequence of amino acids in different positions of the PrP there is a tendency for instability. By a change of the structure stable, protease-resistent molecules (PrPRES) develop, that connect to complexes (fibrills, amyloid). In the cells, PrPRES induce transformation of the PrP into the stable form, that accumulates in the neurons and causes degeneration. The number of neurons diminishes and that of glia cells increases. In sheep scrapie develops. Intake of PrPRES by meat meal of infected sheep effects the development of bovine spongiform encephalopathy.