Simultaneous single-molecule detection of the acetyltransferase and crotonyltransferase activities of histone acetylation writer p300.

We demonstrate for the first time the simultaneous measurement of the acetyltransferase (HAT) and crotonyltransferase (HCT) activities of histone acetylation writer p300 by integrating antibody-based fluorescence labeling with single molecule detection. This methods exhibits good specificity and high sensitivity. Moreover, it can accurately evaluate the kinetic parameters of both the HAT and HCT activities of p300 and screen inhibitors.