title: Cloning and characterization of four rabbit aldo-keto reductases featuring broad substrate specificity for xenobiotic and endogenous carbonyl compounds: relationship with multiple forms of drug ketone reductases.
abstract: Multiple forms of reductases for several drug ketones were isolated from rabbit liver, but their interrelationship and physiologic roles remain unknown. We isolated cDNAs for four aldo-keto reductases (AKR1C30, AKR1C31, AKR1C32, and AKR1C33), which share high amino acid sequence identity with the partial sequences of two rabbit naloxone reductases. The four recombinant enzymes reduced a variety of carbonyl compounds, including endogenous α-dicarbonyls (e.g., isatin and diacetyl), aldehydes (e.g., farnesal and 4-oxo-2-nonenal), and ketosteroids. They differed in specificity for drug ketones and ketosteroids. Although daunorubicin and befunolol were common substrates of all of the enzymes, AKR enzymes specifically reduced naloxone (AKR1C30, AKR1C32, and AKR1C33), metyrapone (AKR1C32 and AKR1C33), loxoprofen (AKR1C31 and AKR1C32), ketotifen (AKR1C30), and naltrexone and fenofibric acid (AKR1C33). AKR1C30 reduced only 17-keto-5β-androstanes, whereas the other enzymes were active toward 3-, 17-, and 20-ketosteroids, and AKR1C33 further reduced 3-keto groups of bile acids and 7α-hydroxy-5β-cholestanes. In addition, AKR1C30, AKR1C31, AKR1C32, and AKR1C33 were selectively inhibited by carbenoxolone, baccharin, phenolphthalein, and zearalenone, respectively. The mRNAs for the four enzymes were ubiquitously expressed in male rabbit tissues, in which highly expressed tissues were the brain, heart, liver, kidney, intestine, colon, and testis (for AKR1C30 and AKR1C31); brain, heart, liver, kidney, testis, lung, and adrenal gland (for AKR1C32); and liver and intestine (for AKR1C33). Thus, the four enzymes correspond to the multiple drug ketone reductases, and may function in the metabolisms of steroids, isatin and reactive carbonyl compounds, and bile acid synthesis.
authors: Gifu Pharmaceutical University, Gifu, Japan (S.E., T.M., Y.A., A.I.); Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan (K.T.); Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, Australia (O.E.); Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan (S.Y.); and Faculty of Engineering (A.H., Y.K.), Gifu University, Gifu, Japan.
authors: Satoshi
authors: S
authors: Endo
authors: Toshiyuki
authors: T
authors: Matsunaga
authors: Yuki
authors: Y
authors: Arai
authors: Akira
authors: A
authors: Ikari
authors: Kazuo
authors: K
authors: Tajima
authors: Ossama
authors: O
authors: El-Kabbani
authors: Shigeru
authors: S
authors: Yamano
authors: Akira
authors: A
authors: Hara
authors: Yukio
authors: Y
authors: Kitade
mesh_terms: D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000438:Alcohols / Q000378:metabolism; D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000447:Aldehydes / Q000378:metabolism; D000074408:Aldo-Keto Reductases; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D007527:Isoenzymes; D007659:Ketones / Q000378:metabolism; D007664:Ketosteroids / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D004364:Pharmaceutical Preparations / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D015262:Xenobiotics / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000438:Alcohols; D000447:Aldehydes; D007527:Isoenzymes; D007659:Ketones; D007664:Ketosteroids; D004364:Pharmaceutical Preparations; D011994:Recombinant Proteins; D015262:Xenobiotics; D000429:Alcohol Oxidoreductases; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase