Figure 2.
H1.4K26 N‐terminal demethylation is catalysed by JmjC KDMs. (A) Demethylation of an H1.4(18–32)K26me3 peptide by KDM4E. The red spectrum shows reactions containing enzyme; the black spectrum is a no enzyme control. (B) Comparison of activity of KDM7A and KDM7B on H1.4K26 and H3K9 methylated peptides. Time course experiments containing the stated enzyme (5 μm) and peptides (10 μm) were carried out at 37 °C, with samples removed and quenched at 8 time‐points. Samples were analysed by MALDI‐TOF MS. (C) Graphs showing the degree of succinate production and peptide demethylation of H1.4(18–32)K26me3 catalysed by KDM4A as quantified by 1H NMR (700 MHz). (D) Comparison of specific activity of KDM4 enzymes (1 μm) with H3(1–15)K9me3 and H1.4(18–32)K26me3 (100 μm). All data show the mean and standard deviation of technical triplicates.