共查询到20条相似文献，搜索用时 0 毫秒
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Alexander J. Lawson Elizabeth A. Walker Scott A. White Timothy R. Dafforn Paul M. Stewart Jonathan P. Ride 《Protein science : a publication of the Protein Society》2009,18(7):1552-1563
11β‐Hydroxysteroid dehydrogenase type 1 (11β‐HSD1) is a key enzyme in the conversion of cortisone to the functional glucocorticoid hormone cortisol. This activation has been implicated in several human disorders, notably the metabolic syndrome where 11β‐HSD1 has been identified as a novel target for potential therapeutic drugs. Recent crystal structures have revealed the presence of a pronounced hydrophobic surface patch lying on two helices at the C‐terminus. The physiological significance of this region has been attributed to facilitating substrate access by allowing interactions with the endoplasmic reticulum membrane. Here, we report that single mutations that alter the hydrophobicity of this patch (I275E, L266E, F278E, and L279E in the human enzyme and I275E, Y266E, F278E, and L279E in the guinea pig enzyme) result in greatly increased yields of soluble protein on expression in E. coli. Kinetic analyses of both reductase and dehydrogenase reactions indicate that the F278E mutant has unaltered Km values for steroids and an unaltered or increased kcat. Analytical ultracentrifugation shows that this mutation also decreases aggregation of both the human and guinea pig enzymes, resulting in greater monodispersity. One of the mutants (guinea pig F278E) has proven easy to crystallize and has been shown to have a virtually identical structure to that previously reported for the wild‐type enzyme. The human F278E enzyme is shown to be a suitable background for analyzing the effects of naturally occurring mutations (R137C, K187N) on enzyme activity and stability. Hence, the F278E mutants should be useful for many future biochemical and biophysical studies of the enzyme. 相似文献
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Yasushi Amano Tomohiko Yamaguchi Tatsuya Niimi Hitoshi Sakashita 《Acta Crystallographica. Section D, Structural Biology》2015,71(4):918-927
Type 5 17β‐hydroxysteroid dehydrogenase (17β‐HSD5) is an aldo‐keto reductase expressed in the human prostate which catalyzes the conversion of androstenedione to testosterone. Testosterone is converted to 5α‐dihydrotestosterone, which is present at high concentrations in patients with castration‐resistant prostate cancer (CRPC). Inhibition of 17β‐HSD5 is therefore considered to be a promising therapy for treating CRPC. In the present study, crystal structures of complexes of 17β‐HSD5 with structurally diverse inhibitors derived from high‐throughput screening were determined. In the structures of the complexes, various functional groups, including amide, nitro, pyrazole and hydroxyl groups, form hydrogen bonds to the catalytic residues His117 and Tyr55. In addition, major conformational changes of 17β‐HSD5 were observed following the binding of the structurally diverse inhibitors. These results demonstrate interactions between 17β‐HSD5 and inhibitors at the atomic level and enable structure‐based drug design for anti‐CRPC therapy. 相似文献
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Urmi Dhagat Vincenzo Carbone Roland P.‐T. Chung Clemens Schulze‐Briese Satoshi Endo Akira Hara Ossama El‐Kabbani 《Acta Crystallographica. Section F, Structural Biology Communications》2007,63(10):825-830
Mouse 3(17)α‐hydroxysteroid dehydrogenase (AKR1C21) is a bifunctional enzyme that catalyses the oxidoreduction of the 3‐ and 17‐hydroxy/keto groups of steroid substrates such as oestrogens, androgens and neurosteroids. The structure of the AKR1C21–NADPH binary complex was determined from an orthorhombic crystal belonging to space group P212121 at a resolution of 1.8 Å. In order to identify the factors responsible for the bifunctionality of AKR1C21, three steroid substrates including a 17‐keto steroid, a 3‐keto steroid and a 3α‐hydroxysteroid were docked into the substrate‐binding cavity. Models of the enzyme–coenzyme–substrate complexes suggest that Lys31, Gly225 and Gly226 are important for ligand recognition and orientation in the active site. 相似文献
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Ossama El‐Kabbani Syuhei Ishikura Armin Wagner Clemens Schulze‐Briese Akira Hara 《Acta Crystallographica. Section F, Structural Biology Communications》2005,61(7):688-690
The 3(17)α‐hydroxysteroid dehydrogenase from mouse is involved in the metabolism of oestrogens, androgens, neurosteroids and xenobiotic compounds. The enzyme was crystallized by the hanging‐drop vapour‐diffusion method in space group P2221, with unit‐cell parameters a = 84.91, b = 84.90, c = 95.83 Å. The Matthews coefficient (VM) and the solvent content were 2.21 Å3 Da−1 and 44.6%, respectively, assuming the presence of two molecules in the asymmetric unit. Diffraction data were collected to a resolution of 1.8 Å at the Swiss Light Source beamline X06SA using a MAR CCD area detector and gave a data set with an overall Rmerge of 6.8% and a completeness of 91.1%. 相似文献
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The enzyme 11β‐hydroxysteroid dehydrogenase 1 (11β‐HSD1) is known to catalyse inactive glucocorticoids into active forms, and its dysregulation in adipose and muscle tissues has been implicated in the development of metabolic syndrome. To delineate the molecular mechanism by which active cortisol has an antagonizing effect against insulin, we optimized the metabolic production of cortisol and its biological functions in myotubes (C2C12). Myotubes supplemented with cortisone actively catalysed its conversion into cortisol, which in turn abolished phosphorylation of Akt in response to insulin treatment. This led to diminished uptake of insulin‐induced glucose. This was corroborated by the application of 11β‐HSD1 inhibitor glycyrrhetinic acid and a glucocorticoid receptor antagonist RU‐486, which reversed completely the antagonizing effects of cortisol on insulin action. Therefore, development of specific inhibitors targeting 11β‐HSD1 might be a promising way to improve impaired insulin‐stimulated glucose uptake. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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D.‐W. Zhu L. Cantin V. Nahoum P. Rehse V. Luu‐The F. Labrie R. Breton S.‐X. Lin 《Acta Crystallographica. Section D, Structural Biology》2001,57(4):589-591
In androgen‐sensitive target tissues, 3α‐hydroxysteroid dehydrogenase regulates the androgen receptor (AR) activity by catalyzing the inactivation of 5α‐dihydrotestosterone (the most natural potent androgen) to 5α‐androstane‐3α,17β‐diol. In this report, the crystallization of a human prostatic type 3 3α‐hydroxysteroid dehydrogenase, a member of the aldo–keto reductase superfamily, is described. Two different crystal forms of the complex between the human type 3 3α‐HSD, NADP+ and testosterone have been obtained using PEG as precipitant. Crystal form I, which diffracts to 1.6 Å, belongs to the monoclinic space group P21, with unit‐cell parameters a = 55.07, b = 87.15, c = 76.88 Å, β = 107.37° and two subunits in the asymmetric unit. A complete data set has been collected at 1.8 Å. Crystal form II, which diffracts to 2.6 Å, belongs to the rhombohedral space group R32, with unit‐cell parameters a = b = 143.59, c = 205.86 Å, α = β = 90, γ = 120° and two subunits in the asymmetric unit. 相似文献
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An 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1) produces glucocorticoid (GC) from 11‐keto metabolite, and its modulation has been suggested as a novel approach to treat metabolic diseases. In contrast, type 2 isozyme 11β‐HSD2 is involved in the inactivation of glucocorticoids (GCs), protecting the non‐selective mineralocorticoid receptor (MR) from GCs in kidney. Therefore, when 11β‐HSD1 inhibitors are pursued to treat the metabolic syndrome, preferential selectivity of inhibitors for type 1 over type 2 isozyme is rather important than inhibitory potency. Primarily, to search for cell lines with 11β‐HSD2 activity, we investigated the expression profiles of enzymes or receptors relevant to GC metabolism in breast, colon, and bone‐derived cell lines. We demonstrated that MCF‐7 cells had high expression for 11β‐HSD2, but not for 11β‐HSD1 with its cognate receptor. Next, for the determination of enzyme activity indirectly, we adopted homogeneous time resolved fluorescence (HTRF) cortisol assay. Obviously, the feasibility of HTRF to cellular 11β‐HSD2 was corroborated by constructing inhibitory response to an 11b‐HSD2 inhibitor glycyrrhetinic acid (GA). Taken together, MCF‐7 that overexpresses type 2 but not type 1 enzyme is chosen for cellular 11β‐HSD2 assay, and our results show that a nonradioactive HTRF assay is applicable for type 2 as well as type 1 isozyme. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Mattsson C Rask E Carlström K Andersson J Eliasson M Ahrén B Söderberg S Olsson T 《Obesity (Silver Spring, Md.)》2007,15(4):887-894
Objective: Reduction of cortisone to cortisol is mediated by 11β‐hydroxysteroid dehydrogenase type 1 (11βHSD1), a putative key enzyme in obesity‐related complications. Experimental studies suggest that adipokines, notably leptin and tumor necrosis factor‐α (TNF‐α), are of importance for 11βHSD1 activity. We hypothesized that the regulation of hepatic preceptor glucocorticoid metabolism is gender‐specific and associated with circulating levels of leptin and TNF‐α receptors and/or sex hormones. Research Methods and Procedures: A total of 34 males and 38 women (14 premenopausal and 22 postmenopausal) underwent physical examination and fasting blood sampling. Insulin sensitivity was tested by euglycemic hyperinsulinemic clamps, and hepatic 11βHSD1 enzyme activity was estimated by the conversion of orally‐ingested cortisone to cortisol. Results: Hepatic 11βHSD1 activity was negatively associated with leptin and soluble TNF (sTNF) r1 and sTNFr2 in males. These correlations remained significant after adjustment for age and insulin sensitivity, and for sTNF‐α receptors also after adjustment of BMI and waist circumference. In contrast, 11β reduction of cortisone was positively associated to leptin in females after adjustment for BMI and waist circumference. Discussion: Hepatic 11β reduction shows different links to circulating adipocyte‐derived hormones in males and females. This emphasizes the need for further studies on tissue‐specific regulation of 11βHSD1 in both genders. 相似文献
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A high level of androstenone in porcine adipose tissue is a major factor contributing to boar taint. Porcine hydroxy‐delta‐5‐steroid dehydrogenase, 3 beta‐ and steroid delta‐isomerase 1 (3β‐HSD, also known as HSD3B1) plays a key role in the hepatic metabolism that catalyzes androstenone to β‐androstenol. Therefore, 3β‐HSD is a candidate gene for boar taint. This study aimed to investigate functional 3β‐HSD polymorphisms in Duroc pigs. We found eight single nucleotide polymorphisms (SNPs) in the full‐length porcine 3β‐HSD. Four of the SNPs had restriction enzyme sites, and we genotyped them in 147 uncastrated male Duroc pigs using a polymerase chain reaction–restriction fragment length polymorphism method. Pigs with the GG genotype at the g.165262G>A locus (SNP5) had significantly lower androstenone levels than did those with other genotypes (P = 0.030). SNP5 also was associated with differences in 3β‐HSD mRNA levels: pigs with the GG genotype had higher levels than those with other genotypes (P = 0.019). The SNP5 polymorphism could affect the hepatic catabolism of androstenone and consequently impact androstenone accumulation in the adipose tissue. Therefore, SNP5 in the 3β‐HSD of Duroc pigs could be a useful selective marker for decreasing boar taint. 相似文献
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Shengyan Su Haimeng Tian Xin Jia Xiaofei Zhu Juanjuan Wu Yali Zhang Yuanyuan Chen Ziqiang Li Yajun Zhou 《Journal of cellular and molecular medicine》2020,24(17):10063-10074
Sterol regulatory element‐binding protein 1c (SREBP1c) plays key roles in maintenance of hepatic stellate cell (HSC) quiescence. The present researches investigated the mechanisms underlying the effects of SREBP1c on HSCs and liver fibrogenesis by HSC‐targeted overexpression of the active SREBP1c using adenovirus in vitro and in vivo. Results demonstrated that SREBP1c exerted inhibitory effects on TAA‐induced liver fibrosis. SREBP1c down‐regulated TGFβ1 level in liver, reduced the receptors for TGFβ1 and PDGFβ, and interrupted the signalling pathways of Smad3 and Akt1/2/3 but not ERK1/2 in HSCs. SREBP1c also led to the decreases in the protein levels of the bromodomain‐containing chromatin‐modifying factor bromodomain protein 4, methionine adenosyltransferase 2B (MAT2B) and TIMP1 in HSCs. In vivo activated HSCs did not express cyclin D1 and cyclin E1 but SREBP1c down‐regulated both cyclins in vitro. SREBP1c elevated PPARγ and MMP1 protein levels in the model of liver fibrosis. The effect of SREBP1c on MAT2B expression was associated with its binding to MAT2B1 promoter. Taken together, the mechanisms underlying the effects of SREBP1c on HSC activation and liver fibrosis were involved in its influences on TGFβ1 level, the receptors for TGFβ1 and PDGFβ and their downstream signalling, and the molecules for epigenetic regulation of genes. 相似文献
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Ju-Hee Lee Ji Yun Jung Eun Jeong Jang Kyung Hwan Jegal Soo Young Moon Sae Kwang Ku Seung Ho Kang Il Je Cho Sook Jahr Park Jong Rok Lee Rong Jie Zhao Sang Chan Kim Young Woo Kim 《Experimental biology and medicine (Maywood, N.J.)》2015,240(4):508-518
Honokiol and magnolol, as pharmacological biphenolic compounds of Magnolia officinalis, have been reported to have antioxidant and anti-inflammatory properties. Sterol regulatory element binding protein-1 c (SREBP-1 c) plays an important role in the development and processing of steatosis in the liver. In the present study, we investigated the effects of a combination of honokiol and magnolol on SREBP-1 c-dependent lipogenesis in hepatocytes as well as in mice with fatty liver due to consumption of high-fat diet (HFD). Liver X receptor α (LXRα) agonists induced activation of SREBP-1 c and expression of lipogenic genes, which were blocked by co-treatment of honokiol and magnolol (HM). Moreover, a combination of HM potently increased mRNA of fatty acid oxidation genes. HM induced AMP-activated protein kinase (AMPK), an inhibitory kinase of the LXRα-SREBP-1 c pathway. The role of AMPK activation induced by HM was confirmed using an inhibitor of AMPK, Compound C, which reversed the ability of HM to both inhibit SREBP-1 c induction as well as induce genes for fatty acid oxidation. In mice, HM administration for four weeks ameliorated HFD-induced hepatic steatosis and liver dysfunction, as indicated by plasma parameters and Oil Red O staining. Taken together, our results demonstrated that a combination of HM has beneficial effects on inhibition of fatty liver and SREBP-1 c-mediated hepatic lipogenesis, and these events may be mediated by AMPK activation. 相似文献
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Jean‐Franois Couture Line Cantin Pierre Legrand Van Luu‐The Fernand Labrie Rock Breton 《Acta Crystallographica. Section D, Structural Biology》2002,58(1):135-139
Progesterone plays an essential role in the maintenance of the pregnancy of most mammals. 20α‐Hydroxysteroid dehydrogenase (20α‐HSD) catalyses the inactivation of progesterone into its inactive form, 20α‐hydroxyprogesterone, and could thus be involved in progesterone withdrawal and in the control of gestation. In this report, the purification and crystallization of recombinant human and rabbit 20α‐HSDs (h20α‐HSD and rb20α‐HSD) are described, two highly homologous enzymes possessing, in addition to their common 20α‐HSD activity, different activities and substrate specificities. Complete diffraction data sets have been collected for crystals of rb20α‐HSD in complex with NADP(H) and with either dihydrotestosterone (1.8 Å), progesterone (1.7 Å) or 4‐androstenedione (1.8 Å). All these crystals belong to the monoclinic space group P21. A partial data set has also been collected for a crystal of h20α‐HSD (P212121) in complex with NADP(H) and progesterone. 相似文献
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Sachiyo Kataoka Shota Nakamura Tadayasu Ohkubo Shigeru Ueda Susumu Uchiyama Yuji Kobayashi Masayuki Oda 《Acta Crystallographica. Section F, Structural Biology Communications》2006,62(6):569-571
The NAD(P)+‐dependent enzyme 3α‐hydroxysteroid dehydrogenase (3α‐HSD) catalyzes the reversible interconversion of hydroxyl and oxo groups at position 3 of the steroid nucleus. The complex of NADH and 3α‐HSD from Pseudomonas sp. B‐0831 was crystallized by the hanging‐drop vapour‐diffusion method. Refinement of crystallization conditions with microseeding improved the quality of the X‐ray diffraction data to a resolution of 1.8 Å. The crystals belonged to the orthorhombic space group P212121, with unit‐cell parameters a = 62.46, b = 82.25, c = 86.57 Å, and contained two molecules, reflecting dimer formation of 3α‐HSD, in the asymmetric unit. 相似文献