title: Arylacetamide Deacetylase is Responsible for Activation of Prasugrel in Human and Dog.
abstract: Prasugrel, a thienopyridine anti-platelet agent, is pharmacologically activated by hydrolysis and hydroxylation. It is efficiently hydrolyzed in the intestine after oral administration, and the enzyme responsible for the hydrolysis in humans was demonstrated to be carboxylesterase (CES)2. Prasugrel hydrolase activity is detected in dog intestines, where CES enzymes are absent; therefore, this prompted us to investigate the involvement of an enzyme(s) other than CES. Human arylacetamide deacetylase (AADAC) is highly expressed in the small intestine, catalyzing the hydrolysis of several clinical drugs containing small acyl moieties. In the present study, we investigated whether AADAC catalyzes prasugrel hydrolysis. Recombinant human AADAC was shown to catalyze prasugrel hydrolysis with a CLint value of 50.0 ± 1.2 ml/min/mg protein with a similar Km value to human intestinal and liver microsomes, whereas the CLint values of human CES1 and CES2 were 4.6 ± 0.1 and 6.6 ± 0.3 ml/min/mg protein, respectively. Inhibition studies using various chemical inhibitors and the relative activity factor approach suggested that the contribution of AADAC to prasugrel hydrolysis in human intestine is comparable to that of CES2. In dog intestine, the expression of AADAC, but not CES1 and CES2, was confirmed by measuring the marker hydrolase activities of each human esterase. The similar Km values and inhibition profiles between recombinant dog AADAC and small intestinal microsomes suggest that AADAC is a major enzyme responsible for prasugrel hydrolysis in dog intestine. Collectively, we found that AADAC largely contributes to prasugrel hydrolysis in both human and dog intestine.
authors.affiliation: Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Kurokawa
authors.affiliation: Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Japan tatsuki@p.kanazawa-u.ac.jp.
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Fukami
authors.affiliation: Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Nakajima
mesh_terms: D000818:Animals; D043182:Carboxylesterase / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002460:Cell Line; D004285:Dogs; D006801:Humans; D006867:Hydrolases / Q000378:metabolism; D006868:Hydrolysis; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D000068799:Prasugrel Hydrochloride / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: D011994:Recombinant Proteins; D006867:Hydrolases; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase; D000068799:Prasugrel Hydrochloride