Inhibitors of Fumarylacetoacetate Hydrolase Domain Containing Protein 1 (FAHD1)

Abstract

FAH domain containing protein 1 (FAHD1) acts as oxaloacetate decarboxylase in mitochondria, contributing to the regulation of the tricarboxylic acid cycle. Guided by a high-resolution X-ray structure of FAHD1 liganded by oxalate, the enzymatic mechanism of substrate processing is analyzed in detail. Taking the chemical features of the FAHD1 substrate oxaloacetate into account, the potential inhibitor structures are deduced. The synthesis of drug-like scaffolds afforded first-generation FAHD1-inhibitors with activities in the low micromolar IC50 range. The investigations disclosed structures competing with the substrate for binding to the metal cofactor, as well as scaffolds, which may have a novel binding mode to FAHD1.

Computational insights into the binding modes, keto–enol tautomerization and stereo-electronically controlled decarboxylation of oxaloacetate in the active site of macrophomate synthase

“…However, the protonation state of oxaloacetate is mainly dependent on the environmental pH value. According to the calculated p K a value (3.7) of the C4-carboxyl group, 56 the doubly deprotonated oxaloacetate may predominate in the optimal physiological pH 7.0 of the MPS enzyme. Thus, in an acidic environment, oxaloacetate is more likely to proceed decarboxylation via the proton migration-assisted decarboxylation mechanism.…”

“…22 Such a huge difference of energy barriers for K-I and K-II is considered to be caused by the stereo-electronic effect of the carboxyl group with different orientations. 31,56 And it is the key factor in controlling the decarboxylation of b-keto acids. As displayed in Scheme 1c, when the breaking C-C bond is approximately orthogonal to the plane of the CQO bond, the two atomic p orbitals in the p-orbital of carbonyl and the soon forming p orbital by breaking the C-C s-bond have a continuous orbital overlap, which significantly stabilizes the pyruvate carbanion and facilitates decarboxylation.…”

Mitochondrial enzyme FAHD1 reduces ROS in osteosarcoma

“…The eukaryotic protein Fumarylacetoacetate hydrolase domain-containing protein 1 (FAHD1) functions as mitochondrial oxaloacetate decarboxylase 11 (ODx) (and oxalacetate keto-enol isomerase 12 ), playing a crucial role in regulating the flux of the tricarboxylic acid cycle 11 , 13 – 15 . FAHD1 belongs to the fumarylacetoacetate hydrolase (FAH) superfamily 13 , 16 , 17 .…”

“…The enzymatic activity of FAHD1 relies on its inherent oxaloacetate isomerase activity 12 , which is crucial for facilitating both acetylpyruvate hydrolase and ODx functions. In our proposed model, the side chains of K47 and K123 play a vital role in stabilizing the carboxylate side chain of D102 13 .…”