p300 (EC 2.3.1.32) or KAT3B, a histone acetyltransferase, contributes to transcriptional activation by acetylating chromatin on the lysine residues of H3 and H4 histones. There is growing evidence that p300 plays an important role in cancer cell proliferation and differentiation. p300 inhibitors have potential applications in cancer therapy. Assay Genie's p300 Inhibitor Screening Kit utilizes a H3 peptide and Acetyl CoA as the substrates. p300 acetylates the peptide and generates CoA-SH with a free thiol group. The CoA is detected using a Thiol Detecting Probe that reacts with thiol groups and gives enhanced fluorescence that can be measured at Ex/Em = 392/482 nm. In the presence of p300 specific inhibitors, the enzymatic activity is inhibited resulting in decreased or total loss of fluorescence. This assay kit is a simple, sensitive, and rapid tool to screen potential inhibitors of p300.

Figure 1: Inhibition of p300 activity by the p300 Inhibitor [Anacardic Acid] (Cat. # 1849). Assays were performed following the kit protocol.