Fig. 3. Acetylation of a mixture of recombinant nucleosomes (0.2 μM as DNA concentration) and HeLa cell extract (non-histone proteins) at 25 °C for 3 h. (a) Background histone acetylation by 4 (2, 5, and 10 μM) or 5 (2, 5, and 10 μM). (b) Catalyzed histone acetylation by 3 (5, 10, 20, 50, and 100 μM) and 5 (5 μM). In (a and b), acetylated lysines were detected by immunoblotting using an anti-Ac-Lys antibody. Proteins were visualized by Oriole staining. (c) Yield of histone acetylation by 3 (5, 10, 20, 50, and 100 μM) and 5 (5 μM). (d) Yield of histone acetylation by 3 (20 μM) and 5 (5, 10, 30, 50, and 100 μM). (e) Yield of histone acetylation by 3 (20 μM) and 6 (1 mM) or 3 (200 μM) and 6 (1, 3, 10, and 30 mM). (f) Yield of histone acetylation by 2 (30 μM) and 6 (1, 3, 10, and 30 mM). In (c–f), the yield of acetylated lysines of the H3 tail was determined by LC-MS/MS analysis. The average and error range (bars) are indicated (n = 2 independent experiments).