Photochemical probe identification of a small-molecule inhibitor binding site in Hedgehog acyltransferase (HHAT)

Journal article

The mammalian membrane-bound O-acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small-molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small-molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure-activity relationship investigation identified single enantiomer IMP-1575, the most potent HHAT inhibitor reported to-date, and guided design of photocrosslinking probes that maintained HHAT-inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small-molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed via kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP-1575 (Ki = 38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.

Authors: Lanyon-Hogg, T; Ritzefeld, M; Zhang, L; Pogranyi, B; Mondal, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Angewandte Chemie International Edition
• Volume: 60
• Issue: 24
• Pages: 13542-13547
• Publication date: 2021-03-26
• Acceptance date: 2021-03-02
• DOI: 10.1002/anie.202014457
• EISSN: 1521-3773
• ISSN: 1433-7851
• Language: English
• Keywords: FFR