3α/β,20β-Hydroxysteroid dehydrogenase (porcine testicular carbonyl reductase) also has a cysteine residue that is involved in binding of cofactor NADPH

Sugiyama, Takuya; Ohno, Shuji; Ghosh, Debashis; Nakajin, Shizuo

doi:10.1016/j.jsbmb.2003.12.013

Cited by 4 publications

(3 citation statements)

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“…Menadione or vitamin K3 is considered a good CBR substrate in humans and other species with K m values in the 5 to 50 M range (Wermuth et al, 1988;Park et al, 1991;Inazu et al, 1992;Bohren et al, 1994;Schaller and Wermuth, 1999;Sugiyama et al, 2004). The K m values for CBR3 V244 and CBR3 M244 did not differ (Student's t test, p ϭ 0.43).…”

Section: Resultsmentioning

confidence: 99%

“…To further characterize the impact of the V244M substitution, we performed kinetic studies with varying concentrations of NADP(H) (Sciotti and Wermuth, 2001;Sugiyama et al, 2004). Interestingly, K mNADP(H) values were similar for both CBR3 isoforms, but the V maxNADP(H) of CBR3 M244 was 1.6-fold higher than the V max -NADP(H) of CBR3 V244 (Student's t test, p ϭ 0.013; Table 2).…”

Section: Resultsmentioning

confidence: 99%

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Functional Significance of a Natural Allelic Variant of Human Carbonyl Reductase 3 (Cbr3)

Lakhman

Ghosh²,

Blanco

2005

Drug Metabolism and Disposition

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ABSTRACT:Human carbonyl reductase (CBR) activity accounts for a significant fraction of the metabolism of endogenous and xenobiotic carbonyl compounds. It is possible that genetic polymorphisms in CBR1 and CBR3 are key for the wide interindividual variability in the disposition of CBR drug substrates. We pinpointed a single nucleotide polymorphism in CBR3 (CBR3 V244M) that encodes for a V244 to M244 change. Blacks showed a higher frequency of the M244 allele (q ‫؍‬ 0.51, n ‫؍‬ 49) than did whites (q ‫؍‬ 0.31, n ‫؍‬ 70; p ‫؍‬ 0.003). In addition, DNA variation panels from 10 ethnic groups presented a wide range of CBR3 V244M genotype distributions. Kinetic experiments with the recombinant CBR3 protein variants and menadione revealed that CBR3 M244 has significantly higher V max than does CBR3 V244 (V max CBR3 M244 ‫؍‬ 40.6 ؎ 1.3 mol/min ⅐ mg versus V max CBR3 V244 ‫؍‬ 19.6 ؎ 2.0 mol/min ⅐ mg, p ‫؍‬ 0.002). In contrast, both isoforms presented similar K m values (K m CBR3 M244 ‫؍‬ 22.9 ؎ 2.9 M versus K m CBR3 V244 ‫؍‬ 24.6 ؎ 3.2 M, p ‫؍‬ 0.43). Assays with NADP(H) demonstrated a higher V maxNADP(H) (1.6-fold) and increased catalytic efficiency (V maxNADP(H) /K mNADP(H) ) for CBR3 M244 compared with CBR3 V244 (p ‫؍‬ 0.013). Comparative three-dimensional analyses based on the structure of the homologous porcine carbonyl reductase suggested that the V244M substitution is positioned in a region critical for interactions with the NADP(H) cofactor. These studies demonstrate that the common CBR3 V244M polymorphism encodes for CBR3 isoforms with distinctive enzymatic properties.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Functional Significance of a Natural Allelic Variant of Human Carbonyl Reductase 3 (Cbr3)

Lakhman

Ghosh²,

Blanco

2005

Drug Metabolism and Disposition

Self Cite

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“…Therefore, CBR1 plays a critical role in detoxification of reactive carbonyl compounds. The pCBR1, also known as 3␣/␤,20␤-hydroxysteroid dehydrogenase (3␣/␤,20␤-HSD), is ubiquitously distributed and the tertiary structure has been reported (Ghosh et al, 2001;Sugiyama et al, 2004). Meanwhile, cCBR1, namely 20␤-hydroxysteroid dehydrogenase, shares approximately 73% sequence homology with pCBR1 and is also widely distributed with no tertiary structure data reported (Bryndová et al, 2006).…”

Section: Carbonyl Reduction Of Mequindoxmentioning

confidence: 99%

Carbonyl Reduction of Mequindox by Chicken and Porcine Cytosol and Cloned Carbonyl Reductase 1

Tang¹,

Mu²,

Wu³

et al. 2012

Drug Metabolism and Disposition

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ABSTRACT:Mequindox (MEQ) is a novel synthetic quinoxaline 1,4-dioxides derivative, which is widely used as a veterinary drug and animal feed additive. However, the metabolic mechanism of MEQ is rarely reported. The N-oxide reduction mechanism of MEQ was reported in our previous work. In this article, the toxicity and the reduction of the carbonyl of MEQ were studied. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assays demonstrated that the carbonyl-reduced MEQ, 2-isoethanol MEQ was much less toxic than MEQ. High-performance liquid chromatography analysis showed that the cytosol extracts of chicken and pig livers were able to reduce MEQ to 2-isoethanol MEQ and the reaction was NADPH-dependent. Further study via enzymeinhibitory experiment revealed that carbonyl reductase 1 (CBR1) participated in this metabolism. The enzyme activity analysis showed that both chicken CBR1 (cCBR1) and porcine CBR1 (pCBR1) were capable of catalyzing the carbonyl reduction of MEQ and its N-oxide reductive metabolite, 1-deoxymequindox. By comparison of the kinetic constants, we observed that the activity of cCBR1 was higher than pCBR1 to MEQ and the standard substrate of CBR1, menadione. On the other hand, both CBR1s exhibited higher activity to 1-deoxymequindox than MEQ. Mutation analysis suggested that the difference of amino acid at position 141/142 may be one possible reason that caused the activity difference between cCBR1 and pCBR1. Thus far, CBR1 was first reported to participate in the carbonyl reduction of MEQ. Our results will be helpful to recognize the metabolic pathways of quinoxaline drugs deeply and to provide a theoretical basis for controlling the negative effects of these drugs.

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Cloning, characterization, sequence analysis and expression patterns in vivo of testicular 20β-hydroxysteroid dehydrogenase cDNA in yellow catfish (Pelteobagrus fulvidraco)

Zhuo

Zhang

Huang

et al. 2011

Comparative Biochemistry and Physiology Part B: Biochemistry an

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3α/β,20β-Hydroxysteroid dehydrogenase (porcine testicular carbonyl reductase) also has a cysteine residue that is involved in binding of cofactor NADPH

Cited by 4 publications

References 18 publications

Functional Significance of a Natural Allelic Variant of Human Carbonyl Reductase 3 (Cbr3)

Functional Significance of a Natural Allelic Variant of Human Carbonyl Reductase 3 (Cbr3)

Carbonyl Reduction of Mequindox by Chicken and Porcine Cytosol and Cloned Carbonyl Reductase 1

Cloning, characterization, sequence analysis and expression patterns in vivo of testicular 20β-hydroxysteroid dehydrogenase cDNA in yellow catfish (Pelteobagrus fulvidraco)

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