A growing number of studies have investigated the interaction between C1q and PrP, but the
oligomeric form of PrP involved in this interaction remains to be determined. Aggregation of
recombinant full-length murine PrP in the presence of 100 mm NaCl allowed us to isolate
three different types of oligomers by size-exclusion chromatography. In contrast to PrP
monomers and fibrils, these oligomers activate the classical complement pathway, the
smallest species containing 8–15 PrP protomers being the most efficient. We used …