Recombinant Histone H3K23me1 (MLA)
Recombinant Xenopus laevis Histone H3 monomethyl Lys23 (H3K23me1) is produced in E. coli and purified using FPLC. The protein contains a substitution of cysteine to alanine at amino acid 110. Recombinant methylated histones are specifically methylated via a chemical alkylation reaction that introduces a methyl lysine analog (MLA). This specific chemical treatment enables the site and degree of methylation to be controlled precisely. Each methylation reaction is over 99% complete, as verified by high-resolution ESI-TOF mass spectrometry. 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. The molecular weight of the recombinant histone is 15,271 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.