16 Antibodies as Tools to Probe Prion Protein Biology

Abstract

Prion diseases are neurodegenerative disorders afflicting animals and humans that are characterized by progressive neurodysfunction and lead invariably to death. Prion diseases have been shown to be inheritable due to mutations in the chromosomal gene encoding the prion protein (PrP), to arise sporadically at low frequencies, or to be acquired through the transmission of infectious prion particles. These features are highly unusual in combination and hint at the unorthodox biological and physico-chemical properties of prion proteins.

Early transmission studies provided clues that the infectious prion agent possessed properties not normally associated with a viral pathogen (Alper et al. 1966; Lartajet et al. 1970). It was some years later, however, before progressive enrichment of infectivity from fractions of diseased hamster brain first identified PrP as an integral component of the infectious scrapie agent (Prusiner 1982; Prusiner et al. 1982). Further investigation of prion disorders has unveiled a unique and unexpected molecular pathology, in which the central event is the aberrant metabolism of the ubiquitous cellular prion protein (PrP^C), the physiological function of which remains poorly understood (Brown et al. 1997; Martins et al. 1997; Rieger et al. 1997; Weiss et al. 1997).

PrP^C is a glycosyl-phosphatidylinositol (GPI) anchored protein composed of 209 amino acids and expressed on a wide variety of tissue types, particularly neurons. However, the disease state is typified by an accumulation in the brain of an abnormal protease-resistant isoform of PrP^C, designated PrP^Sc. Intensive scrutiny from diverse experimental perspectives has been directed toward unraveling the molecular events governing...