Rapid expression of polymorphic ovine prion proteins and studies on their protease sensitivity

We have used coupled and uncoupled in vitro transcription/translation to express rapidly aglycosyl ovine prion proteins from ovine genomic DNA genotyped for scrapie susceptible and nonsusceptible polymorphisms. Unlike previous in vitro studies of prion proteins, this method does not require cloning or laborious extractions. To our knowledge, this is the first report of ovine PrP expression at low (ng) levels under the control of an Escherichia coli promoter and ribosome binding site both coded for in the polymerase chain reaction primer. The rapidity of this approach could form the basis of a high throughput screening assay for PrP interactions, as proteins were expressed in a matter of hours from genomic DNA as the starting material. There was no difference observed in proteinase K sensitivity between prion translation products containing either scrapie susceptible or nonsusceptible polymorphisms.