NR ACDQ
AU Cai,K.; Miller,J.L.; Stenland,C.J.; Gilligan,K.J.; Hartwell,R.C.; Terry,J.C.; Evans-Storms,R.B.; Rubenstein,R.; Petteway,S.R.Jr.; Lee,D.C.
TI Solvent-dependent precipitation of prion protein
QU Biochimica et Biophysica Acta 2002 May 20; 1597(1): 28-35
PT journal article
AB The misfolded isoform of the prion protein (PrPsc) possesses many unusual physiochemical properties. Previously, we and others reported on the differential partitioning of PrPsc from plasma derived therapeutic proteins during their purification processes. To understand the driving force behind these partitioning differences, we investigated the effects of various solvent conditions on the precipitation of PrPsc. In a physiological buffer, PrPsc remained in the supernatant after low speed centrifugation. At pH 5, PrPsc precipitation was nearly complete regardless of the salt content. PrPsc could also be precipitated at pH 8 by adding ethanol, but this precipitation was salt dependent. Based on these observations, an empirical mathematical model was constructed in which the PrPsc precipitation trends were fully described as a function of solvent pH, salt, and ethanol concentration. This model consistently predicted PrPsc partitioning during cold ethanol precipitation steps used in plasma protein purification processes, as shown by experimentally determined distributions of PrPsc and transmissible spongiform encephalopathy (TSE) infectivity. These results indicate that pH, salt, and ethanol content are the major solvent factors determining the precipitation of the infectious PrPsc in these processes and may provide a useful tool for assessing the differential partitioning of PrPsc in a given solvent environment.
MH Algorithms; Animal; Blood Proteins/*chemistry; Comparative Study; Ethanol; Hamsters; Hydrogen-Ion Concentration; PrPsc Proteins/*chemistry; Precipitation; Prions/chemistry/*isolation & purification; Sodium Chloride; Solvents
AD Department of Pathogen Safety and Research/Biological Products, Bayer Corporation, 85 T.W. Alexander Dr., Research Triangle Park, NC 27709, USA. kang.cai.b@bayer.com
SP englisch
PO Niederlande
OR Prion-Krankheiten C