Structure-Specific Effects of Thyroxine Analogs on Human Liver 3 -Hydroxysteroid Dehydrogenase

Yamamoto, Tohei; Nozaki, Ayumu; Shintani, Syunichi; Ishikura, Satoshi; Katagiri, Yuki; Hara, Akira

doi:10.1093/oxfordjournals.jbchem.a022722

Cited by 9 publications

(10 citation statements)

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“…AKR1C4 has been reported to be activated by sulfobromophthalein (BSP), cloˆbric acid derivatives 28) and thyroxines. 31) The activators of AKR1C4 enhanced the dehydrogenase activity of jpDD4, but not that of cyDD1.…”

Section: Methodsmentioning

confidence: 97%

Molecular Characterization of Two Monkey Dihydrodiol Dehydrogenases

Higaki

Kamiya

Usami

et al. 2002

Drug Metabolism and Pharmacokinetics

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Japanese monkey liver contains multiple forms of dihydrodiol dehydrogenase with 3(20)alpha-hydroxysteroid dehydrogenase activity. Here we have purified the major and minor forms (DD1 and DD4) of the enzyme from Cynomolgus monkey liver, and isolated cDNA species for the two enzyme forms by reverse transcription-PCR. The cDNAs encoded proteins comprising of 323 amino acids, in which the sequence identity between DD1 and DD4 was 83%. The sequences deduced from the cDNAs for DD1 and DD4 perfectly matched the partial sequences of peptides derived from the respective enzymes. We also isolated the cDNAs for DD1 and DD4 of Japanese monkey liver, which had almost identical amino acid sequences with those of the respective enzymes of Cynomolgus monkey liver. The monkey DD1s and DD4s showed the highest sequence identity (94%) with AKR1C1 and AKR1C4, respectively, of four isoenzymes of human 3(20)alpha-hydroxysteroid dehydrogenase, which belongs to the aldo-keto reductase family. The substrate specificity and inhibitor sensitivity of the purified recombinant Cynomolgu monkey DD1 and Japanese monkey DD4 were also essentially identical to those of the recombinant AKR1C1 and AKR1C4, respectively, indicating that DD1 and DD4 are homologues of human AKR1C1 and AKR1C4, respectively. The mRNA for DD1 was detected only in liver, kidney, intestine and adrenal gland among Japanese monkey tissues, and that for DD4 was expressed in liver and kidney. These tissue distribution patterns differ from those of human AKR1C1 and AKR1C4, which are expressed ubiquitously and liver-specific, respectively. In addition, no mRNA for an enzyme corresponding to another isoenzyme (AKR1C2) of the human enzyme was detected in livers of the two monkey strains. The results suggest a difference in the metabolism of steroids and xenobiotics mediated by 3(20)alpha-hydroxysteroid dehydrogenase isoenzymes between monkeys and humans.

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Section: Methodsmentioning

confidence: 97%

Molecular Characterization of Two Monkey Dihydrodiol Dehydrogenases

Higaki

Kamiya

Usami

et al. 2002

Drug Metabolism and Pharmacokinetics

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“…The apparent kinetic constants were determined with five different concentrations of the substrate or coenzyme in the presence of the saturated concentration of the corresponding coenzyme or substrate by fitting the data to the Michaelis-Menten equation. The K d value for the binding of NADP(H) to the wild-type (WT) or mutant enzymes (each 1 M) was determined by measuring protein intrinsic fluorescence as described for determination of the values for thyroxine derivatives (18), except that the excitation wavelength of 295 nm was chosen to minimize photodecomposition of the enzymes. The kinetic constants and K d values are expressed as the means of at least triplicate determinations.…”

Section: Methodsmentioning

confidence: 99%

Roles of His-79 and Tyr-180 of -Xylose/Dihydrodiol Dehydrogenase in Catalytic Function

Asada

Aoki

Ishikura

et al. 2000

Biochemical and Biophysical Research Communications

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“…SDS\PAGE on a 12.5 % (w\v) slab gel [34] and Western blot analysis with antibodies against AKR1C4 [27] were performed as described. The effects of activators on the fluorescence of the enzyme (1.0 µM) were determined at 25 mC in 0.1 M potassium phosphate buffer, pH 7.4 [13,15].…”

Section: Other Methodsmentioning

confidence: 99%

“…The K d values for the binding of NADP + to WT and the mutant enzymes were determined by measuring protein fluorescence as described for the determination of the values for thyroxine derivatives [15], except that an excitation wavelength of 295 nm was chosen to minimize photodecomposition of the enzymes. Although the K d for NADP + was obtained by incremental addition of the coenzyme (0.05-2.0 µM) to the enzyme solution (1.0 µM in 0.1 M potassium phosphate, pH 7.0), the enzyme was not saturated with 0.5 mM NAD + because of its low affinity.…”

Section: Determination Of K D Values For Nad(p) +mentioning

confidence: 99%

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Kinetic alteration of a human dihydrodiol/3α-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine

Ohta¹,

Tatuya²,

Ishikura³

et al. 2000

Biochem. J.

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Human dihydrodiol dehydrogenase with 3alpha-hydroxysteroid dehydrogenase activity exists in four forms (AKR1C1-1C4) that belong to the aldo-keto reductase (AKR) family. Recent crystallographic studies on the other proteins in this family have indicated a role for a tyrosine residue (corresponding to position 216 in these isoenzymes) in stacking the nicotinamide ring of the coenzyme. This tyrosine residue is conserved in most AKR family members including AKR1C1-1C3, but is replaced with histidine in AKR1C4 and phenylalanine in some AKR members. In the present study we prepared mutant enzymes of AKR1C4 in which His-216 was replaced with tyrosine or phenylalanine. The two mutations decreased 3-fold the K(m) for NADP(+) and differently influenced the K(m) and k(cat) for substrates depending on their structures. The kinetic constants for bile acids with a 12alpha-hydroxy group were decreased 1.5-7-fold and those for the other substrates were increased 1.3-9-fold. The mutation also yielded different changes in sensitivity to competitive inhibitors such as hexoestrol analogues, 17beta-oestradiol, phenolphthalein and flufenamic acid and 3,5,3', 5'-tetraiodothyropropionic acid analogues. Furthermore, the mutation decreased the stimulatory effects of the enzyme activity by sulphobromophthalein, clofibric acid and thyroxine, which increased the K(m) for the coenzyme and substrate of the mutant enzymes more highly than those of the wild-type enzyme. These results indicate the importance of this histidine residue in creating the cavity of the substrate-binding site of AKR1C4 through the orientation of the nicotinamide ring of the coenzyme, as well as its involvement in the conformational change by binding non-essential activators.

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Structure-Specific Effects of Thyroxine Analogs on Human Liver 3 -Hydroxysteroid Dehydrogenase

Cited by 9 publications

References 0 publications

Molecular Characterization of Two Monkey Dihydrodiol Dehydrogenases

Molecular Characterization of Two Monkey Dihydrodiol Dehydrogenases

Roles of His-79 and Tyr-180 of -Xylose/Dihydrodiol Dehydrogenase in Catalytic Function

Kinetic alteration of a human dihydrodiol/3α-hydroxysteroid dehydrogenase isoenzyme, AKR1C4, by replacement of histidine-216 with tyrosine or phenylalanine

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