Fig. 2. Assay development of AlphaScreen-based HTS platform. (a) Schematic representation of AlphaScreen assay for the detection of hGCN5 enzymatic activity. (b) The enzyme titration curve in the presence of 100 nM biotinylated H3 (1–23) peptide substrate and 15 μM acetyl-CoA. (c) The cofactor titration curve with the concentration of acetyl-CoA ranging from 8 nM to 50 μM. (d) Z-factor determination of established AlphaScreen assays. Data in panels (b and c) is presented as mean ± SD, n = 3.