HDAC11 is an enzyme which belongs to the Histone Deacetylase (HDAC) class of enzymes. However, HDAC11 has a high defatty-acylase activity while its deacetylation activity is virtually nonexistent. The defatty-acylase activity of HDAC11 is linked to increased interferon I signaling, suggesting that inhibition of HDAC11 can be used to treat diseases by modulating the immune response. However, no potent and selective inhibitors for the defatty-acylase activity of HDAC11 exist. The previously available HDAC11-selective inhibitors such as FT895 and SIS17 show limited or no ability to prevent this activity in cell cultures. Alternatively, Trapoxin A has micromolar inhibition of the defatty-acylase activity, but also inhibits other HDACs.
Researchers at Cornell University and at GW modified Trapoxin A to interact with an additional binding site on HDAC11 creating TD034, which has nanomolar potency for HDAC11 defatty-acylase activity in enzymatic assays and is selective relative to other HDACs. Moreover, studies done by the researchers showed that TD034 is a tight binding reversible inhibitor and functions in cell culture at micromolar potency. In addition to this, the researchers showed that it is active at low micromolar concentration and inhibits defatty-acylation of SHM-2, a known substrate of HDAC11.
Figure: In cell culture, TD034 demonstrates micromolar inhibition of HDAC11 defatty-acylation activity. Meanwhile, FT895 lacked activity and SIS17 had lower potency.
Trapoxin A Analogue as a Selective Nanomolar Inhibitor of HDAC11. Thanh Tu Ho, Changmin Peng, Edward Seto, Hening Lin. ACS Chem Biol. 2023 Apr 21;18(4):803-809.