Histone Demethylases: Background, Purification, and Detection

Posttranslational modification of histone proteins is a highly regulated epigenetic event. Lysine demethylases modulate gene expression states and chromatin structure by catalyzing the removal of methyl groups from lysine residues in the histone tails. This chapter provides a historical background of the discovery and different classes of demethylase enzymes and a summary of the methods most commonly used to express and purify these proteins. We also provide an overview of current technologies used to assess demethylase enzymatic activity both in vitro and in vivo.