Fig. 1
Antibody 029-2 shows high selectivity for amyloid-β (Aβ) peptides starting with the phenylalanine residue in position 4. Synthetic Aβ peptides with different N-termini were analyzed by capillary isoelectric focusing immunoassay (a, b) or by urea-bicine/bis-tris/Tris/sulfate sodium dodecyl sulfate (SDS)-PAGE followed by Western blotting (c, d). Mixtures of Aβ1–40, Aβ2–40, and Aβ5–40 (top electropherogram), Aβ3–40 (second electropherogram), AβpE3–40 (third electropherogram), and Aβ4–40 (bottom electropherogram) were subjected to isoelectric focusing in microcapillaries and probed with antibody IC16 (a) or 029-2 (b). Note that the electropherograms shown were derived from different experiments. A set of synthetic Aβ peptides was separated by urea-bicine/bis-tris/Tris/sulfate SDS-PAGE, blotted onto polyvinylidene difluoride membranes and probed with 029-2 (c). After a washing step, the same blot was reprobed with 6E10 (d). With both methods, 029-2 exclusively detected Aβ4–x peptides, whereas the control antibodies also recognized Aβ peptides with other N-termini