EPR study of the interactions between dendrimers and peptides involved in Alzheimer's and prion diseases

Spin-probe and spin-label techniques were used to study the interactions of the A beta 1-28 peptide involved in Alzheimer disease and the PrP 106-126 peptide suspected to be preferentially involved in spongiform encephalopathies with three different types of dendrimers. A computer-aided EPR analysis of a positively charged and a neutral spin probe was performed by comparing the pure dendrimer and peptide systems with the dendrimer-peptide ones. Also spin-labeled PAMAM dendrimers were used to test the interactions. The results show the interactions between dendrimer and peptide monomer to be stronger for A beta 1-28 than for PrP 106-126. PAMAM dendrimers perturb the aggregation of the peptides more than PPI dendrimers do.