Inhibition by Aplidine of the aggregation of the prion peptide PrP 106-126 into beta-sheet fibrils.

Aplidine, a cyclic peptide, from the tunicate Aplidium albican, prevents the in vitro aggregation into beta-sheet containing fibrils of the prion peptide 106-126 when co-incubated in a 1:1 molar ratio. The blocking of fibril formation induced by Aplidine has clear sequence specificity, being much stronger for the 106-126 prion peptide than for the beta-amyloid 25-35 peptide. In addition to the known ability of Aplidine to cross the plasmatic membrane, these results indicate that Aplidine is a potential leading compound for the development of therapeutic blockers of prion aggregation.