Figure 4

Western blot analysis of monoclonal antibody PFO specificity. A. Two different Aβ40 PFOs samples (O1 and O2) and Aβ40 "monomer" (M) were prepared as described in Methods. None of the PFO specific monoclonal antibodies stain Aβ monomer, although the "monomer" sample is recognized by the 6E10 control antibody. Different Mabs stain distinct size distributions of Aβ PFOs. OC polyclonal sera stains high MW bands in oligomer preparation O1 and low MW bands in preparation O2. B. PFO specific monoclonal antibodies recognize soluble oligomers of Aβ42 and other types of amyloids. Soluble oligomers were prepared from Aβ, PrP 109-149 and α-synuclein as described in Methods. Aggregates were analyzed by Western blot with 6E10, A11, and monoclonal antibodies 55, 204, and 205. 6E10 only recognizes Aβ peptide. A11 detects oligomers of different sizes that are formed by Aβ and other types of amyloids. Monoclonal antibodies preferentially recognize different subsets of A11 positive oligomers.