Fig 1. Interaction of metals with PrPC induced a change to low solubility.
Immunoblot analysis of brain homogenates (10%) derived from C57BL wild-type mice, bovine, human and sheep is as indicated. Homogenates were pre-incubated with various metal ions (1 mM) followed by centrifugation to generate a protein fraction of high solubility in the supernatant and of low solubility in the pellet. The pellet fractions were re-suspended in homogenate buffer back to the original volume. Following the addition of sample buffer, proteins were denatured by heating, and identical volumes were loaded for separation on SDS-PAGE and subsequent immunoblotting. PrPC specific signals were detected on immunoblots by mab SAF34 and visualized using a chemiluminescence substrate. Unlike other metals, the interaction of ZnCl2 with PrPC led to reduced protein solubility in samples from all four species.