A Novel Reaction Mediated by Human Aldehyde Oxidase: Amide Hydrolysis of GDC-0834

• DOI: 10.1124/dmd.114.061804
• Publication Date: 2015-04-07T02:03:26Z
• Authors: Jasleen K Sodhi; Susan Wong; Donald S Kirkpatrick; Lichuan Liu; S. Cyrus Khojasteh; Cornelis E. C. A Hop; John T Barr; Jeffrey P Jones; Jason S Halladay
• Keywords: Amide; Aldehyde oxidase; Peptide bond

GDC-0834, a Bruton's tyrosine kinase inhibitor investigated as potential treatment of rheumatoid arthritis, was previously reported to be extensively metabolized by amide hydrolysis such that no measurable levels this compound were detected in human circulation after oral administration. In vitro studies liver cytosol determined GDC-0834 (<i>R</i>)-<i>N</i>-(3-(6-(4-(1,4-dimethyl-3-oxopiperazin-2-yl)phenylamino)-4-methyl-5-oxo- 4,5-dihydropyrazin-2-yl)-2-methylphenyl)-4,5,6,7-tetrahydrobenzo[<i>b</i>] thiophene-2-carboxamide) rapidly hydrolyzed with CL_int 0.511 ml/min per milligram protein. Aldehyde oxidase (AO) and carboxylesterase (CES) putatively identified the enzymes responsible cytosolic fractionation mass spectrometry-proteomics analysis enzymatically active fractions. Results confirmed series kinetic experiments inhibitors AO, CES, xanthine (XO), which implicated AO but not XO, mediating hydrolysis. Further supporting interaction between shown potent reversible six known substrates IC₅₀ values ranging from 0.86 1.87 <i>μ</i>M. Additionally, silico modeling suggest is capable binding site bond near molybdenum cofactor (MoCo), orientated way enable nucleophilic attack on carbonyl hydroxyl MoCo. Together, results involvement GDC-0834.