3AM9

Complex of bovine xanthine dehydrogenase and trihydroxy FYX-051

Summary for 3AM9

• Entry DOI: 10.2210/pdb3am9/pdb
• Related: 3AMZ 3AN1
• Descriptor: Xanthine dehydrogenase/oxidase, FE2/S2 (INORGANIC) CLUSTER, CALCIUM ION, ... (10 entities in total)
• Functional Keywords: xanthine oxidoreductase, xanthine dehydrogenase, fyx-051, oxidoreductase
• Biological source: Bos taurus (Bovine)
• Cellular location: Cytoplasm (By similarity): P80457
• Total number of polymer chains: 2
• Total formula weight: 298432.41

Authors

Matsumoto, K.,Okamoto, K.,Ashizawa, N.,Matsumura, T.,Kusano, T.,Nishino, T. (deposition date: 2010-08-18, release date: 2010-11-03, Last modification date: 2023-11-01)

Primary citation

Matsumoto, K.,Okamoto, K.,Ashizawa, N.,Nishino, T.
FYX-051: A Novel and Potent Hybrid-Type Inhibitor of Xanthine Oxidoreductase
J.Pharmacol.Exp.Ther., 336:95-103, 2011

PubMed Abstract: 4-[5-(Pyridin-4-yl)-1H-1,2,4-triazol-3-yl]pyridine-2-carbonitrile (FYX-051) is a potent inhibitor of bovine milk xanthine oxidoreductase (XOR). Steady-state kinetics study showed that it initially behaved as a competitive-type inhibitor with a K(i) value of 5.7 × 10(-9) M, then after a few minutes it formed a tight complex with XOR via a Mo-oxygen-carbon atom covalent linkage, as reported previously (Proc Natl Acad Sci USA 101:7931-7936, 2004). Thus, FYX-051 is a hybrid-type inhibitor exhibiting both structure- and mechanism-based inhibition. The FYX-051-XOR complex decomposed with a half-life of 20.4 h, but the enzyme activity did not fully recover. This was found to be caused by XOR-mediated conversion of FYX-051 to 4-[5-(2-hydroxypyridin-4-yl)-1H-1,2,4-triazol-3-yl]pyridine-2-carbonitrile (2-hydroxy-FYX-051), as well as formation of 6-hydroxy-4-[5-(2-hydroxypyridin-4-yl)-1H-1,2,4-triazol-3-yl]pyridine-2-carbonitrile (dihydroxy-FYX-051) and 4-[5-(2,6-dihydroxypyridin-4-yl)-1H-1,2,4-triazol-3-yl]-6-hydroxypyridine-2-carbonitrile (trihydroxy-FYX-051) during prolonged incubation for up to 72 h. A distinct charge-transfer band was observed concomitantly with the formation of the trihydroxy-FYX-051-XOR complex. Crystallographic analysis of the charge-transfer complex indicated that a Mo-nitrogen-carbon bond was formed between molybdenum of XOR and the nitrile group of trihydroxy-FYX-051. FYX-051 showed a potent and long-lasting hypouricemic effect in a rat model of potassium oxonate-induced hyperuricemia, and it seems to be a promising candidate for the clinical treatment of hyperuricemia.

PubMed: 20952484
DOI: 10.1124/jpet.110.174540

Experimental method

X-RAY DIFFRACTION (2.17 Å)