A Novel Polymorphic Allele of Human Arylacetamide Deacetylase Leads to Decreased Enzyme Activity

Shimizu, Mai; Fukami, Tatsuki; Kobayashi, Yuki; Takamiya, Masataka; Aoki, Yasuhiro; Nakajima, Miki; Yokoi, Tsuyoshi

doi:10.1124/dmd.112.044883

Cited by 34 publications

(48 citation statements)

References 28 publications

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“…Recombinant human AADAC, CES1, and CES2 expressed in baculovirus-infected insect cells were prepared as previously described Watanabe et al, 2010). The homogenates of COS7 cells, fibroblast-like cell line from monkey kidney tissue, expressing AADAC.1, AADAC.2, and AADAC.3 were prepared as in our previous study (Shimizu et al, 2012). All other chemicals used in this study were of analytical or the highest quality commercially available.…”

Section: Methodsmentioning

confidence: 99%

“…We previously found polymorphic alleles of the human AADAC gene (Shimizu et al, 2012): AADAC*2 and AADAC*3. The AADAC proteins encoded by AADAC*2 and AADAC*3 are AADAC.2 and AADAC.3.…”

Section: Methodsmentioning

confidence: 99%

“…The AADAC protein from wild-type AADAC*1 is AADAC.1. Recombinant AADAC.2 and AADAC.3, prepared as in our previous study (Shimizu et al, 2012), were used to determine the effects of genetic polymorphisms of the AADAC gene on the indiplon hydrolase activity. In addition, the indiplon hydrolase activity of the individual HLM samples, the AADAC genotype of which was previously determined (Shimizu et al, 2012), was also measured.…”

Section: Methodsmentioning

confidence: 99%

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Indiplon Is Hydrolyzed by Arylacetamide Deacetylase in Human Liver

Shimizu¹,

Fukami²,

Ito³

et al. 2014

Drug Metab Dispos

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Human arylacetamide deacetylase (AADAC) catalyzes the hydrolysis of some clinically used drugs, but the information available on its substrates is limited. To increase our knowledge of the AADAC substrates, we examined whether AADAC catalyzes the hydrolysis of indiplon, which was initially developed as a hypnotic sedative drug. It has been reported that approximately 30-40% of the administered indiplon was hydrolyzed to deacetylindiplon in humans, but the enzyme responsible for this hydrolysis had not been identified. We detected high levels of indiplon hydrolase activity in human liver microsomes (HLMs), but the levels found in human liver cytosol and plasma were scarcely detectable. Recombinant AADAC showed a high level of indiplon hydrolase activity, whereas recombinant carboxylesterase 1 (CES1) and 2 (CES2) showed marginal activity. The indiplon hydrolase activity of HLM was potently inhibited by vinblastine, a potent inhibitor of AADAC and CES2, but it was not inhibited by digitonin and telmisartan, inhibitors of CES1 and CES2, respectively. In a panel of 24 individual HLM samples, the indiplon hydrolase activities were significantly correlated with the hydrolase activities of flutamide, phenacetin, and rifampicin, which are known AADAC substrates. An HLM sample with a homozygous AADAC*3 allele, which was previously found to exhibit decreased enzyme activity, showed the lowest indiplon hydrolase activity among the 24 tested samples. Collectively, we found that human AADAC is responsible for the hydrolysis of indiplon. Thus, we can add indiplon to the list of human AADAC substrates.

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Section: Methodsmentioning

confidence: 99%

“…We previously found polymorphic alleles of the human AADAC gene (Shimizu et al, 2012): AADAC*2 and AADAC*3. The AADAC proteins encoded by AADAC*2 and AADAC*3 are AADAC.2 and AADAC.3.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Indiplon Is Hydrolyzed by Arylacetamide Deacetylase in Human Liver

Shimizu¹,

Fukami²,

Ito³

et al. 2014

Drug Metab Dispos

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“…4A). The results of a later study found that this sample has a polymorphic allele of AADAC gene, which causes the decreased enzyme activity (Shimizu et al, 2012).…”

Section: Resultsmentioning

confidence: 76%

Contributions of Arylacetamide Deacetylase and Carboxylesterase 2 to Flutamide Hydrolysis in Human Liver

Kobayashi

Fukami²,

Shimizu³

et al. 2012

Drug Metab Dispos

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ABSTRACT:Flutamide, an antiandrogen drug, is widely used for the treatment of prostate cancer. The major metabolic pathways of flutamide are hydroxylation and hydrolysis. The hydrolyzed metabolite, 5-amino-2-nitrobenzotrifluoride (FLU-1), is further metabolized to N-hydroxy FLU-1, an assumed hepatotoxicant. Our previous study demonstrated that arylacetamide deacetylase (AADAC), one of the major serine esterases expressed in the human liver and gastrointestinal tract, catalyzes the flutamide hydrolysis. However, the enzyme kinetics in human tissue microsomes were not consistent with the kinetics by recombinant human AADAC. Thus, it seemed that AADAC is not the sole enzyme responsible for flutamide hydrolysis in human. In the present study, we found that recombinant carboxylesterase (CES) 2 could hydrolyze flutamide at low concentrations of flutamide. In the inhibition assay, the flutamide hydrolase activities at a flutamide concentration of 5 M in human liver and jejunum microsomes were strongly inhibited by a selective CES2 inhibitor, 10 M loperamide, with the residual activities of 22.9 ؎ 3.5 and 18.6 ؎ 0.7%, respectively. These results suggest that CES2 is also involved in the flutamide hydrolysis in human tissues. Using six individual human livers, the contributions of AADAC and CES2 to flutamide hydrolysis were estimated by using the relative activity factor. The relative contribution of CES2 was approximately 75 to 99% at the concentration of 5 M flutamide. In contrast, the relative contribution of AADAC increased in parallel with the concentration of flutamide. Thus, CES2, rather than AA-DAC, largely contributed to the flutamide hydrolysis in clinical therapeutics.

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“…Se ha reportado que es una enzima relacionada al metabolismo de RIF, miembro de la superfamilia de serina esterasa, la cual se expresa en el hígado y en el tracto gastrointestinal (36) . Uno de los polimorfismos que ha sido reportado por afectar la actividad de esta enzima es AADAC*3: 14008T>C. Esta enzima está siendo considerada y analizada en un estudio actual del Instituto Nacional de Salud en pacientes con tuberculosis, trabajo en el que reportarán los genotipos presentes en nuestra población.…”

Section: Aadacunclassified