Figure 3.

(A-D) Dose-dependent binding assay of 2E6, 2G10, 1B6, 1D4 and ALPA antibodies to the isolated unconjugated mono-acetylated peptides. Antibody concentrations ranged between 0.2 and 6.6 nM. The c-Myc (138–162) acetylated peptides were used as negative controls. (E) Binding of anti-APE1 and ALPA antibodies to Myc (138–162) derived and another unrelated acetylated peptide (N_1–13), used as negative controls for anti-APE-1 antibodies. As expected, no binding was detected for anti-APE1 antibodies. ALPA, instead, bound in a dose-response manner all the acetylated peptides. Experiments were performed in triplicate and expressed as values ± sd. (F) Binding of 4 anti-APE1 and ALPA antibodies to acetylated proteins. As expected, no binding was detected for the anti-APE1 antibodies toward the unrelated proteins, whereas they bound the chemically acetylated APE-1. ALPA strongly bound all the acetylated proteins.