Recombinant Histone H3K9me2 (EPL)

Recombinant Histone H3 dimethyl Lys9 (H3K9me2) proteins are generated using expressed protein ligation (EPL) technology. Truncated human Histone H3.2 is produced in E. coli and purified using FPLC. The purified protein is subsequently ligated to a N-terminal histone tail peptide containing dimethyl lysine 9 via a native peptide bond. The full-length protein is then repurified prior to lyophilization. Protein concentration was determined using the molar extinction coefficient for Histone H3 and absorbance at 280nm. The recombinant histone is >98% pure by SDS-PAGE and confirmed by high-resolution ESI-TOF mass spectrometry. The molecular weight of the recombinant histone is 15,253 Daltons. Histone H3 is one of the core components of the nucleosome. The nucleosome is the smallest subunit of chromatin and consists of 146 base pairs of DNA wrapped around an octamer of core histone proteins (two each of H2A, H2B, H3 and H4). Histone H1 is a linker protein, present at the interface between the nucleosome core and DNA entry/exit points.