NR AWCC
AU Biasini,E.; Thellung,S.; Chiesa,R.; Harris,D.A.
TI Characterization of a novel, soluble form of mutant PrP from the brains of transgenic mice
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Oral sessions ORAL-13
PT Konferenz-Vortrag
AB A nine-octapeptide insertion in the prion protein (PrP) gene is associated with an inherited form of prion disease. Transgenic (Tg) mice that express the mouse homologue of this mutation (designated PG14) accumulate in their brains an insoluble and weakly protease-resistant form of the mutant protein that resembles PrPsc. This mutant PrP is highly neurotoxic, but it is not infectious. In contrast, when Tg(PG14) mice are inoculated with the RML strain of scrapie, they accumulate a form of PG14 PrP that is highly protease resistant and infectious upon serial passages. This RML-seeded form of the protein (PG14RML) displays different biological and molecular properties from the non-infectious form (PG14Spon). Here, we describe the isolation and the characterization of a soluble form of PG14 (called PG14Sol), which differs from PG14Spon and PG14RML in several biochemical features. PG14Sol was purified by immunoprecipitation followed by Cu2+-IMAC, while aggregated PG14Spon and PG14RML were isolated by differential centrifugation. PG14Spon and PG14RML, like PrPsc, are insoluble in non-ionic detergents, protease-resistant, precipitated by PTA, and unable to bind Cu2+-IMAC. In contrast PG14Sol, like PrPc, is soluble, protease-sensitive, not-precipitated by PTA, and capable of binding Cu2+-IMAC. In addition, CDI experiments, which compare the accessibility of several different antibody epitopes, indicate that the conformation of PG14Sol resembles that of PrPc, while PG14Spon and PG14RML are similar to PrPsc. Our data indicate that PG14Sol represents a common substrate for formation of both PG14Spon and PG14RML. We are currently attempting to generate PG14Spon and PG14RML from PG14Sol substrate using in vitro conversion reactions. The identification of PG14Sol contributes to the definition of the molecular events responsible for the pathology observed in Tg(PG14) mice and raises the possibility that this soluble form may represent a toxic species of PG14.
AD E. Biasini, S. Thellung, D. Harris: Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis (MO), USA; R. Chiesa: Dulbecco Telethon Institute and Mario Negri Institute for Pharmacological Research, Milan, Italy. E-mail: ebiasini@cellbiology.wustl.edu
SP englisch
PO Italien