Background:

C646, a pyrazolone-containing small molecule, is a cell-permeable histone acetyltransferase (HAT) inhibitor that competitively and selectively inhibits the HAT activity of p300, a transcriptional co-activator involved in a variety of gene regulatory pathways and protein acetylation events, with the inhibition constant Ki value of 400 nM and the half maximal inhibition concentration IC50 value of 1.6 μM [1].

C646 binds to p300 as the Z-isomer forming hydrogen bonds between Thr1411, tYR1467, Trp1466 and Arg1410 on the side chains of p300 and oxygen atoms of C646 [1].

C646 is also capable of inhibiting a variety of p300 HAT mutants, including T1411A, Y1467F, W1466F and R1410A with IC50 values of 3.4 μM, 7 μM, 5 μM and 2.5 μM respectively [1].

Reference

参考文献:
[1] Bowers EM, Yan G, Mukherjee C, Orry A, Wang L, Holbert MA, Crump NT, Hazzalin CA, Liszczak G, Yuan H, Larocca C, Saldanha SA, Abagyan R, Sun Y, Meyers DJ, Marmorstein R, Mahadevan LC, Alani RM, Cole PA. Virtual ligand screening of the p300/CBP histone acetyltransferase: identification of a selective small molecule inhibitor. Chem Biol. 2010 May 28;17(5):471-82. doi: 10.1016/j.chembiol.2010.03.006.