Mapping the N- and C-termini of the ~55- and the ~15- kDa, 6E10-immunoreactive proteins.

(A) CSF samples were immunoprecipitated using either 22C11 or 1G7, directed against APP66-81 and APP380-665, respectively, and WB was probed with biotinylated 6E10. Neither antibody captured the ~55- or the ~15- kDa proteins. (B) CSF samples were immunoprecipitated using 6E10, and immunocaptured proteins were detected using biotinylated 2B3, directed against the α-secretase cleavage site of APP. Neither the ~55- nor the ~15- kDa proteins were detected. In both experiments, mouse IgG (msIgG) was used as a negative control capture reagent. * = non-specific bands.