Colorimetric Histone Acetyltransferase Activity Assay

Histone acetyltransferases (HATs) catalyze the acetylation of histone proteins by transferring an acetyl group from cofactor acetyl-CoA, and consequently regulate gene expression. The regulation is critical for cellular processes such as cell differentiation and proliferation. Our Colorimetric Histone Acetyltransferase (HAT) Activity Assay Kit offers rapid and sensitive detection of HAT activity or HAT inhibition in mammalian cells/tissue samples. Briefly, acetylation of a peptide substrate by HATs releases the free form of CoA, which can serve as a coenzyme of a NADH generating enzyme to produce NADH. The stoichiometric NADH production can be quantified by spectrophotometric analysis at 440 nm upon reacting with water soluble tetrazolium-1 (WST-1), a soluble tetrazolium dye. The HAT assay does not require radioactivity or chromatography and can be applied for kinetic studies. HATs' counteracting enzymes, histone deacetylases (HDACs), do not interfere with the assay, consequently crude nuclear extract or cell lysate samples can be used.