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Norlin M, Wikvall K. Enzymatic activation in vitamin D signaling - Past, present and future. Arch Biochem Biophys 2023; 742:109639. [PMID: 37196753 DOI: 10.1016/j.abb.2023.109639] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/10/2023] [Accepted: 05/14/2023] [Indexed: 05/19/2023]
Abstract
Vitamin D signaling is important in regulating calcium homeostasis essential for bone health but also displays other functions in cells of several tissues. Disturbed vitamin D signaling is linked to a large number of diseases. The multiple cytochrome P450 (CYP) enzymes catalyzing the different hydroxylations in bioactivation of vitamin D3 are crucial for vitamin D signaling and function. This review is focused on the progress achieved in identification of the bioactivating enzymes and their genes in production of 1α,25-dihydroxyvitamin D3 and other active metabolites. Results obtained on species- and tissue-specific expression, catalytic reactions, substrate specificity, enzyme kinetics, and consequences of gene mutations are evaluated. Matters of incomplete understanding regarding the physiological roles of some vitamin D hydroxylases are critically discussed and the authors will give their view of the importance of each enzyme for vitamin D signaling. Roles of different vitamin D receptors and an alternative bioactivation pathway, leading to 20-hydroxylated vitamin D3 metabolites, are also discussed. Considerable progress has been achieved in knowledge of the vitamin D3 bioactivating enzymes. Nevertheless, several intriguing areas deserve further attention to understand the pleiotropic and diverse activities elicited by vitamin D signaling and the mechanisms of enzymatic activation necessary for vitamin D-induced responses.
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Affiliation(s)
- Maria Norlin
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
| | - Kjell Wikvall
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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Shang S, He Z, Hou W, Chen X, Zhao X, Han H, Chen S, Yang S, Tai F. Molecular cloning, expression analysis and functional characterization of chicken cytochrome P450 27A1: A novel mitochondrial vitamin D 3 25-hydroxylase. Poult Sci 2023; 102:102747. [PMID: 37276702 PMCID: PMC10258509 DOI: 10.1016/j.psj.2023.102747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 04/05/2023] [Accepted: 04/19/2023] [Indexed: 06/07/2023] Open
Abstract
Vitamin D3 is hydroxylated by cytochrome P450 (CYP) before exerting biological effects. The chicken CYP involved in vitamin D3 25-hydroxylation has yet to be cloned, and little is known about its functional characteristics, tissue distribution, and cellular expression. We identified a novel, full-length CYP27A1 gene cloned from chicken hepatocyte cDNA that encodes a putative protein of 518 amino acids. Swiss modeling revealed that chicken CYP27A1 has a classic open-fold form. Multisequence homology alignment determined that CYP27A1 contains conserved motifs for substrate recognition and binding. Quantitative real-time PCR analysis in 2-mo-old Partridge Shank broilers demonstrated that CYP27A1 mRNA levels were highest in the liver, followed by the thigh muscles, the breast muscles, and kidneys. The transcripts of CYP27A1 in breast muscles were significantly higher in males than in females. A subcellular localization analysis demonstrated that CYP27A1 was mainly expressed in the mitochondria. In vitro enzyme assays suggested that recombinant CYP27A1 hydroxylates vitamin D3 at the C-25 position to form 25-hydroxyvitamin D3 (25(OH)D3). The Km and Vmax values for CYP27A1-dependent vitamin D3 25-hydroxylation were estimated to be 4.929 μM and 0.389 mol min-1 mg-1 protein, respectively. In summary, these results suggest that CYP27A1 encodes a mitochondrial CYP that plays an important physiologic role in the 25-hydroxylation of vitamin D3 in chickens, providing novel insights into vitamin D3 metabolism in this species.
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Affiliation(s)
- S Shang
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, China; Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, China; Qinba State Key Laboratory of Biological Resources and Ecological Environment (Incubation), Hanzhong, China; Qinba Mountain Area Collaborative Innovation Center of Bioresources Comprehensive Development, China
| | - Z He
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - W Hou
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - X Chen
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, China
| | - X Zhao
- Hanzhong Central Hospital, Hanzhong, China
| | - H Han
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, China
| | - S Chen
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, China
| | - S Yang
- Shaanxi Province Key Laboratory of Bio-Resources, Shaanxi University of Technology, Hanzhong, China
| | - F Tai
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, China.
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Wang Z, Zeng Y, Jia H, Yang N, Liu M, Jiang M, Zheng Y. Bioconversion of vitamin D 3 to bioactive calcifediol and calcitriol as high-value compounds. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:109. [PMID: 36229827 PMCID: PMC9563128 DOI: 10.1186/s13068-022-02209-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/04/2022] [Indexed: 11/07/2022]
Abstract
Biological catalysis is an important approach for the production of high-value-added compounds, especially for products with complex structures. Limited by the complex steps of chemical synthesis and low yields, the bioconversion of vitamin D3 (VD3) to calcifediol and calcitriol, which are natural steroid products with high added value and significantly higher biological activity compared to VD3, is probably the most promising strategy for calcifediol and calcitriol production, and can be used as an alternative method for chemical synthesis. The conversion efficiency of VD3 to calcifediol and calcitriol has continued to rise in the past few decades with the help of several different VD3 hydroxylases, mostly cytochrome P450s (CYPs), and newly isolated strains. The production of calcifediol and calcitriol can be systematically increased in different ways. Specific CYPs and steroid C25 dehydrogenase (S25DH), as VD3 hydroxylases, are capable of converting VD3 to calcifediol and calcitriol. Some isolated actinomycetes have also been exploited for fermentative production of calcifediol and calcitriol, although the VD3 hydroxylases of these strains have not been elucidated. With the rapid development of synthetic biology and enzyme engineering, quite a lot of advances in bioproduction of calcifediol and calcitriol has been achieved in recent years. Therefore, here we review the successful strategies of promoting VD3 hydroxylation and provide some perspective on how to further improve the bioconversion of VD3 to calcifediol and calcitriol.
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Affiliation(s)
- Zheyi Wang
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Yan Zeng
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China
| | - Hongmin Jia
- China Animal Husbandry Industry Co. Ltd, Beijing, 100095 China
| | - Niping Yang
- grid.256885.40000 0004 1791 4722School of Life Sciences, Hebei University, No. 180 Wusi Dong Road, Baoding, 071002 China
| | - Mengshuang Liu
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Mingyue Jiang
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049 China
| | - Yanning Zheng
- grid.9227.e0000000119573309State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing, 100101 China
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Erfanian S, Roustazadeh A. Lack of association between CYP27B1 gene polymorphism and type 2 diabetes mellitus in Iranian patients. J Diabetes Metab Disord 2022; 21:517-520. [PMID: 35673421 PMCID: PMC9167340 DOI: 10.1007/s40200-022-01003-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/07/2022] [Indexed: 11/27/2022]
Abstract
Purpose Type 2 diabetes mellitus (T2DM) is a global health problem with multiple etiological factors. Previous studies indicated that 1- alpha, 25-dihydroxyvitamin D3, a molecule that is produced by CYP27B1, could protect insulin-secreted cells from destruction by immune cells. The aim of the study was to investigate the CYP27B1 promoter gene polymorphism in T2DM. Methods Two hundred subjects including 100 T2DM and 100 healthy individuals were recruited in the study. ARMS-PCR technique was used to identify rs10877012 genotypes in the 5' region of CYP27B1. Results The frequency of CC, CA, and AA genotype was 61/50, 31/39, and 8/11, respectively in T2DM patients compared to healthy subjects. There was no significant difference between both groups in regarding to genotype and allele distribution (P > 0.05). CA (RR = 1.535, 95% CI = 0.841- 2.802) and AA (1.677, 95% CI = 0.627-4.490) genotypes had no association with increased risk of T2DM. In addition, CA + AA versus CC showed no increased risk for T2DM (RR = 0.639, 95% CI = 0.365-1.121). Conclusion We found no association between rs10877012 polymorphism and T2DM. There was no increased risk of this polymorphism in T2DM. Further studies with large groups are suggested in other populations to better understand the relation of CYP27B1 gene variation, especially its ethnicity-dependent relation with T2DM.
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Affiliation(s)
- Saiedeh Erfanian
- Department of Tissue Engineering, Faculty of Basic Sciences and Advanced Medical Technologies, Royan Institute, ACECR, Tehran, Iran
| | - Abazar Roustazadeh
- Department of Biochemistry, Department of Advanced Medical Sciences and Technologies, Research Center for Non-Communicable Diseases, Jahrom University of Medical Sciences, Ostad motahhari Blvd, POBox 74148-46199, Jahrom, Iran
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Sakamoto R, Nagata A, Ohshita H, Mizumoto Y, Iwaki M, Yasuda K, Sakaki T, Nagasawa K. Chemical Synthesis of Side-Chain-Hydroxylated Vitamin D 3 Derivatives and Their Metabolism by CYP27B1. Chembiochem 2021; 22:2896-2900. [PMID: 34250710 DOI: 10.1002/cbic.202100250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/07/2021] [Indexed: 11/09/2022]
Abstract
1α,25-Dihydroxyvitamin D3 (abbreviated here as 1,25D3 ) is a hormonally active form of vitamin D3 (D3 ), and is produced from D3 by CYP27 A1-mediated hydroxylation at C25, followed by CYP27B1-mediated hydroxylation at C1. Further hydroxylation of 25D3 and 1,25D3 occurs at C23, C24 and C26 to generate corresponding metabolites, except for 1,25R,26D3 . Since the capability of CYP27B1 to hydroxylate C1 of side-chain-hydroxylated metabolites other than 23S,25D3 and 24R,25D3 has not been examined, we have here explored the role of CYP27B1 in the C1 hydroxylation of a series of side-chain-hydroxylated D3 derivatives. We found that CYP27B1 hydroxylates the R diastereomers of 24,25D3 and 25,26D3 more effectively than the S diastereomers, but shows almost no activity towards either diastereomer of 23,25D3 . This is the first report to show that CYP27B1 metabolizes 25,26D3 to the corresponding 1α-hydroxylated derivative, 1,25,26D3 . It will be interesting to examine the physiological relevance of this finding.
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Affiliation(s)
- Ryota Sakamoto
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, 184-8588, Tokyo, Japan
| | - Akiko Nagata
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, 184-8588, Tokyo, Japan
| | - Haruki Ohshita
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Yuka Mizumoto
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, 184-8588, Tokyo, Japan
| | - Miho Iwaki
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, 184-8588, Tokyo, Japan
| | - Kaori Yasuda
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Toshiyuki Sakaki
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, 184-8588, Tokyo, Japan
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Machalz D, Pach S, Bermudez M, Bureik M, Wolber G. Structural insights into understudied human cytochrome P450 enzymes. Drug Discov Today 2021; 26:2456-2464. [PMID: 34161845 DOI: 10.1016/j.drudis.2021.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 05/06/2021] [Accepted: 06/14/2021] [Indexed: 01/02/2023]
Abstract
Human cytochrome P450 (CYP) enzymes are widely known for their pivotal role in the metabolism of drugs and other xenobiotics as well as of endogenous chemicals. In addition, CYPs are involved in numerous pathophysiological pathways and, hence, are therapeutically relevant. Remarkably, a portion of promising CYP targets is still understudied and, as a consequence, untargeted, despite their huge therapeutic potential. An increasing number of X-ray and cryo-electron microscopy (EM) structures for CYPs have recently provided new insights into the structural basis of CYP function and potential ligand binding. This structural knowledge of CYP functionality is essential for both understanding metabolism and exploiting understudied CYPs as drug targets. In this review, we summarize and highlight structural knowledge about this enzyme class, with a focus on understudied CYPs and resulting opportunities for structure-based drug design. Teaser: This review summarizes recent structural insights into understudied cytochrome P450 enzymes. We highlight the impact of molecular modeling for mechanistically explaining pathophysiological effects establishing understudied CYPs as promising drug targets.
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Affiliation(s)
- David Machalz
- Pharmaceutical and Medicinal Chemistry (Computer-Aided Drug Design), Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Szymon Pach
- Pharmaceutical and Medicinal Chemistry (Computer-Aided Drug Design), Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Marcel Bermudez
- Pharmaceutical and Medicinal Chemistry (Computer-Aided Drug Design), Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Matthias Bureik
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 30072, China.
| | - Gerhard Wolber
- Pharmaceutical and Medicinal Chemistry (Computer-Aided Drug Design), Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany.
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Lin MY, Lim LM, Tsai SP, Jian FX, Hwang SJ, Lin YH, Chiu YW. Low dose ultraviolet B irradiation at 308 nm with light-emitting diode device effectively increases serum levels of 25(OH)D. Sci Rep 2021; 11:2583. [PMID: 33510382 PMCID: PMC7844009 DOI: 10.1038/s41598-021-82216-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 01/15/2021] [Indexed: 11/24/2022] Open
Abstract
This animal study aimed to elucidate the relationship of low-dose, narrow-band UVB at 308 nm with vitamin D synthesis. C57BL/6 female mice, at 3 weeks-of-age, were randomly divided into the following six groups (n = 6 at each time point of vitamin D measurement), which were: (1) normal diet without UVB irradiation; (2) VDd diet without UVB irradiation; and (3)-(6) VDd diet with 308 nm-UVB irradiation of 12.5, 25, 50, and 100 μω/cm2, respectively. All of the groups needing UVB irradiation received an exposure of 10 min per day, five days per week, and a duration of 3-5 weeks. The mice recovering from severe VDd (plasma total 25-hydroxyvitamin D level increasing from approximately 3 to over 30 ng/mL) only occurred in groups with a UVB irradiation dosage of either 50 or 100 μω/cm2. The optimal, estimated dosage for mice to recover from severe VDd was 355 mJ/cm2 within 3 weeks. Low-dose, narrow-band UVB irradiation at 308 nm is effective in improving VDd in mice. The results obtained, in addition to the especially small side effects of the above UVB irradiation formula, could be further translated to treating VDd-related disorders.
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Affiliation(s)
- Ming-Yen Lin
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan
- Department of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Lee Moay Lim
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Siao-Ping Tsai
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan
| | - Feng-Xuan Jian
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan
| | - Shang-Jyh Hwang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan
- Department of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
- Institute of Population Health Sciences, National Health Research Institutes, Miaoli, 350, Taiwan
| | - Yu-Hsuan Lin
- Taiwan Instrument Research Institute, National Applied Research Laboratories, Hsinchu, 300, Taiwan.
| | - Yi-Wen Chiu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, TzYou 1st Rd., Sanmin District, Kaohsiung City, 80708, Taiwan.
- Department of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
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Li L, Liu S, Yu J. Autoimmune thyroid disease and type 1 diabetes mellitus: same pathogenesis; new perspective? Ther Adv Endocrinol Metab 2020; 11:2042018820958329. [PMID: 32973994 PMCID: PMC7493255 DOI: 10.1177/2042018820958329] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/20/2020] [Indexed: 12/14/2022] Open
Abstract
Autoimmune thyroid disease (AITD) and type 1 diabetes mellitus (T1DM) are two common autoimmune diseases that can occur concomitantly. In general, patients with diabetes have a high risk of AITD. It has been proposed that a complex genetic basis together with multiple nongenetic factors make a variable contribution to the pathogenesis of T1DM and AITD. In this paper, we summarize current knowledge in the field regarding potential pathogenic factors of T1DM and AITD, including human leukocyte antigen, autoimmune regulator, lymphoid protein tyrosine phosphatase, forkhead box protein P3, cytotoxic T lymphocyte-associated antigen, infection, vitamin D deficiency, and chemokine (C-X-C motif) ligand. These findings offer an insight into future immunotherapy for autoimmune diseases.
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Affiliation(s)
- Liyan Li
- Department of Endocrinology, First People’s Hospital of Jinan, Jinan, People’s Republic of China
| | - Shudong Liu
- Department of Endocrinology, Shandong Rongjun General Hospital, Jinan, People’s Republic of China
| | - Junxia Yu
- Department of Endocrinology, Tengzhou Central People’s Hospital, 181 Xingtan Road, Tengzhou, Shandong Province, 277500, People’s Republic of China
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Analysis of In Vivo Activity of the Bovine Cholesterol Hydroxylase/Lyase System Proteins Expressed in Escherichia coli. Mol Biotechnol 2019; 61:261-273. [PMID: 30729436 DOI: 10.1007/s12033-019-00158-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The cholesterol hydroxylase/lyase (CHL) system, located in the mitochondria of the mammalian adrenal cortex cells, consists of cytochrome P450scc (CYP11A1), adrenodoxin (Adx), and adrenodoxin reductase (AdR) and performs the first stage of the steroidogenesis: AdR and Adx enable the electron transfer between NADPH and cytochrome P450scc, and P450scc catalyzes the conversion of cholesterol into pregnenolone. CHL system was reconstructed in Escherichia coli using the polycistronic plasmid pTrc99A/CHL. In E. coli cells, the recombinant proteins form the catalytically active system. CHL activity towards 22R-hydroxycholesterol was 4.0 ± 1.3 nmol pregnenolone/h per 1 mg homogenate protein. The alteration of the order of heterologous cDNAs in the expression cassette from AdR-Adx-P450scc to P450scc-Adx-AdR results in alteration of stoichiometric ratio P450scc/Adx/AdR from 1:1.45:4.2 to 1:1.67:0.98; the former ratio is more optimal for the functioning of the cytochrome P450scc. The application of modified cDNA of Adx (AdxS112W) does not increase the CHL activity; however, the introduction of the second copy of AdxS112W gene into the expression cassette increases both the expression level of АdxS112W and the CHL activity in comparison with P450scc/АdxS112W/AdR system. In vivo activity of the CHL system in bacteria is limited by the substrate uptake by bacterial cells: it varied in the range of 0.05-0.62 mg pregnenolone/l resting cell suspension per 1-day cultivation, depending on the type and concentration of permeabilizing agents in the medium. The obtained results contribute to the knowledge of CHL system functioning in living bacteria.
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Tuckey RC, Cheng CYS, Slominski AT. The serum vitamin D metabolome: What we know and what is still to discover. J Steroid Biochem Mol Biol 2019; 186:4-21. [PMID: 30205156 PMCID: PMC6342654 DOI: 10.1016/j.jsbmb.2018.09.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/04/2018] [Accepted: 09/04/2018] [Indexed: 01/08/2023]
Abstract
Vitamin D, referring to the two forms, D2 from the diet and D3 primarily derived from phototransformation in the skin, is a prohormone important in human health. The most hormonally active form, 1α,25-dihydroxyvitamin D (1α,25(OH)2D), formed from vitamin D via 25-hydroxyvitamin D (25(OH)D), is not only important for regulating calcium metabolism, but has many pleiotropic effects including regulation of the immune system and has anti-cancer properties. The major circulating form of vitamin D is 25(OH)D and both D2 and D3 forms are routinely measured by LC/MS/MS to assess vitamin D status, due to their relatively long half-lives and much higher concentrations compared to 1α,25(OH)2D. Inactivation of both 25(OH)D and 1α,25(OH)2D is catalyzed by CYP24A1 and 25-hydroxyvitamin D3 3-epimerase. Initial products from these enzymes acting on 25(OH)D3 are 24R,25(OH)2D3 and 3-epi-25(OH)D3, respectively, and both of these can also be measured routinely in some clinical laboratories to further document vitamin D status. With advances in LC/MS/MS and its increased availability, and with the help of studies with recombinant vitamin D-metabolizing enzymes, many other vitamin D metabolites have now been detected and in some cases quantitated, in human serum. CYP11A1 which catalyzes the first step in steroidogenesis, has been found to also act on vitamins D3 and D2 hydroxylating both at C20, but with some secondary metabolites produced by subsequent hydroxylations at other positions on the side chain. The major vitamin D3 metabolite, 20S-hydroxyvitamin D3 (20S(OH)D3), shows biological activity, often similar to 1α,25(OH)2D3 but without calcemic effects. Using standards produced enzymatically by purified CYP11A1 and characterized by NMR, many of these new metabolites have been detected in human serum, with semi-quantitative measurement of 20S(OH)D3 indicating it is present at comparable concentrations to 24R,25(OH)2D3 and 3-epi-25(OH)D3. Recently, vitamin D-related hydroxylumisterols derived from lumisterol3, a previtamin D3 photoproduct, have also been measured in human serum and displayed biological activity in initial in vitro studies. With the current extensive knowledge on the reactions and pathways of metabolism of vitamin D, especially those catalyzed by CYP24A1, CYP27A1, CYP27B1, CYP3A4 and CYP11A1, it is likely that many other of the resulting hydroxyvitamin D metabolites will be measured in human serum in the future, some contributing to a more detailed understanding of vitamin D status in health and disease.
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Affiliation(s)
- Robert C Tuckey
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia.
| | - Chloe Y S Cheng
- School of Molecular Sciences, The University of Western Australia, Perth, WA, 6009, Australia
| | - Andrzej T Slominski
- Department of Dermatology, University of Alabama at Birmingham, AL, 35294, USA; Comprehensive Cancer Center Cancer Chemoprevention Program, University of Alabama at Birmingham, AL, 35294, USA; VA Medical Center, Birmingham, AL, 35294, USA
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In silico analysis of the functional non-synonymous single nucleotide polymorphisms in the human CYP27B1 gene. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2018. [DOI: 10.1016/j.ejmhg.2018.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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12
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Detection of novel CYP11A1-derived secosteroids in the human epidermis and serum and pig adrenal gland. Sci Rep 2015; 5:14875. [PMID: 26445902 PMCID: PMC4597207 DOI: 10.1038/srep14875] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/10/2015] [Indexed: 01/18/2023] Open
Abstract
To investigate whether novel pathways of vitamin D3 (D3) and 7-dehydrocholesterol (7DHC) metabolism initiated by CYP11A1 and previously characterized in vitro, occur in vivo, we analyzed samples of human serum and epidermis, and pig adrenals for the presence of intermediates and products of these pathways. We extracted human epidermis from 13 individuals and sera from 13 individuals and analyzed them by LC/qTOF-MS alongside the corresponding standards. Pig adrenal glands were also analyzed for these steroids and secosteroids. Epidermal, serum and adrenal samples showed the presence of D3 hydroxy-derivatives corresponding to 20(OH)D3, 22(OH)D3, 25(OH)D3, 1,25(OH)2D3, 20,22(OH)2D3, 20,23(OH)2D3, 20,24(OH)2D3, 20,25(OH)2D3, 20,26(OH)2D3, 1,20,23(OH)3D3 and 17,20,23(OH)3D3, plus 1,20(OH)2D3 which was detectable only in the epidermis. Serum concentrations of 20(OH)D3 and 22(OH)D3 were only 30- and 15-fold lower than 25(OH)D3, respectively, and at levels above those required for biological activity as measured in vitro. We also detected 1,20,24(OH)3D3, 1,20,25(OH)3D3 and 1,20,26(OH)3D3 in the adrenals. Products of CYP11A1 action on 7DHC, namely 22(OH)7DHC, 20,22(OH)27DHC and 7-dehydropregnenolone were also detected in serum, epidermis and the adrenal. Thus, we have detected novel CYP11A1-derived secosteroids in the skin, serum and adrenal gland and based on their concentrations and biological activity suggest that they act as hormones in vivo.
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Advances and computational tools towards predictable design in biological engineering. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:369681. [PMID: 25161694 PMCID: PMC4137594 DOI: 10.1155/2014/369681] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/09/2014] [Indexed: 11/21/2022]
Abstract
The design process of complex systems in all the fields of engineering requires a set of quantitatively characterized components and a method to predict the output of systems composed by such elements. This strategy relies on the modularity of the used components or the prediction of their context-dependent behaviour, when parts functioning depends on the specific context. Mathematical models usually support the whole process by guiding the selection of parts and by predicting the output of interconnected systems. Such bottom-up design process cannot be trivially adopted for biological systems engineering, since parts function is hard to predict when components are reused in different contexts. This issue and the intrinsic complexity of living systems limit the capability of synthetic biologists to predict the quantitative behaviour of biological systems. The high potential of synthetic biology strongly depends on the capability of mastering this issue. This review discusses the predictability issues of basic biological parts (promoters, ribosome binding sites, coding sequences, transcriptional terminators, and plasmids) when used to engineer simple and complex gene expression systems in Escherichia coli. A comparison between bottom-up and trial-and-error approaches is performed for all the discussed elements and mathematical models supporting the prediction of parts behaviour are illustrated.
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Jacobs ET, Van Pelt C, Forster RE, Zaidi W, Hibler EA, Galligan MA, Haussler MR, Jurutka PW. CYP24A1 and CYP27B1 polymorphisms modulate vitamin D metabolism in colon cancer cells. Cancer Res 2013; 73:2563-73. [PMID: 23423976 DOI: 10.1158/0008-5472.can-12-4134] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Vitamin D is a well-studied agent for cancer chemoprevention and treatment. Its chief circulating metabolite, 25-hydroxyvitamin D, is converted into the active hormone 1,25-dihydroxyvitamin D (1,25D) by the cytochrome P450 enzyme CYP27B1 in kidney and other tissues. 1,25D is then deactivated by CYP24A1 and ultimately catabolized. Colorectal carcinoma cells express CYP27B1 and CYP24A1 that locally regulate 1,25D with potential implications for its impact on carcinogenesis. While 1,25D inhibits cancer growth, the effects of polymorphic variations in genes encoding proteins involved in 1,25D homeostasis are poorly understood. Using an RXR-VDR mammalian two-hybrid (M2H) biologic assay system, we measured vitamin D metabolite uptake and activation of the vitamin D receptor (VDR) pathway in colon cancer cells that expressed one of five CYP27B1 single-nucleotide polymorphisms (SNP) or four CYP24A1 SNPs. Compared with the wild-type control, four of five CYP27B1 SNPs reduced enzymatic activity, whereas one (V166L) increased activity. For CYP24A1, all tested SNPs reduced enzyme activity. Quantitative real-time PCR analyses supported the results of M2H experiments. The observed SNP-directed variation in CYP functionality indicated that vitamin D homeostasis is complex and may be influenced by genetic factors. A comprehensive understanding of 1,25D metabolism may allow for a more personalized approach toward treating vitamin D-related disorders and evaluating risk for carcinogenesis.
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Affiliation(s)
- Elizabeth T Jacobs
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
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15
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Makeeva DS, Dovbnya DV, Donova MV, Novikova LA. Functional reconstruction of bovine P450scc steroidogenic system in <i>Escherichia coli</i>. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ajmb.2013.34023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Tang EKY, Tieu EW, Tuckey RC. Expression of human CYP27B1 inEscherichia coliand characterization in phospholipid vesicles. FEBS J 2012; 279:3749-3761. [DOI: 10.1111/j.1742-4658.2012.08736.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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17
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Sakaki T, Sugimoto H, Hayashi K, Yasuda K, Munetsuna E, Kamakura M, Ikushiro S, Shiro Y. Bioconversion of vitamin D to its active form by bacterial or mammalian cytochrome P450. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1814:249-56. [PMID: 20654743 DOI: 10.1016/j.bbapap.2010.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 06/29/2010] [Accepted: 07/12/2010] [Indexed: 10/19/2022]
Abstract
Bioconversion processes, including specific hydroxylations, promise to be useful for practical applications because chemical syntheses often involve complex procedures. One of the successful applications of P450 reactions is the bioconversion of vitamin D₃ to 1α,25-dihydroxyvitamin D₃. Recently, a cytochrome P450 gene encoding a vitamin D hydroxylase from the CYP107 family was cloned from Pseudonocardia autotrophica and is now applied in the bioconversion process that produces 1α,25-dihydroxyvitamin D₃. In addition, the directed evolution study of CYP107 has significantly enhanced its activity. On the other hand, we found that Streptomyces griseolus CYP105A1 can convert vitamin D₃ to 1α,25-dihydroxyvitamin D₃. Site-directed mutagenesis of CYP105A1 based on its crystal structure dramatically enhanced its activity. To date, multiple vitamin D hydroxylases have been found in bacteria, fungi, and mammals, suggesting that vitamin D is a popular substrate of the enzymes belonging to the P450 superfamily. A combination of these cytochrome P450s would produce a large number of compounds from vitamin D and its analogs. Therefore, we believe that the bioconversion of vitamin D and its analogs is one of the most promising P450 reactions in terms of practical application.
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Affiliation(s)
- Toshiyuki Sakaki
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
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18
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Ewen KM, Kleser M, Bernhardt R. Adrenodoxin: the archetype of vertebrate-type [2Fe-2S] cluster ferredoxins. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1814:111-25. [PMID: 20538075 DOI: 10.1016/j.bbapap.2010.06.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/28/2010] [Accepted: 06/01/2010] [Indexed: 11/15/2022]
Abstract
Adrenodoxin is probably the best characterized member of the vertebrate-type [2Fe-2S]-cluster ferredoxins. It has been in the spotlight of scientific interest for many years due to its essential role in mammalian steroid hormone biosynthesis, where it acts as electron mediator between the NADPH-dependent adrenodoxin reductase and several mitochondrial cytochromes P450. In this review we will focus on the present knowledge about protein-protein recognition in the mitochondrial cytochrome P450 system and the modulation of the electron transfer between Adx and its redox partners, AdR and CYP(s). We also intend to point out the potential biotechnological applications of Adx as a versatile electron donor to different cytochromes P450, both in vitro and in vivo. Finally we will address the comparison between the mammalian cytochrome P450-associated adrenodoxin and ferredoxins involved in iron-sulfur-cluster biosynthesis. Despite their different functions, these proteins display an amazing similarity regarding their primary sequence, tertiary structure and biophysical features.
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Affiliation(s)
- Kerstin Maria Ewen
- Department of Biochemistry, Saarland University, D-66041 Saarbrücken, Germany
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19
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Tang EKY, Voo KJQ, Nguyen MN, Tuckey RC. Metabolism of substrates incorporated into phospholipid vesicles by mouse 25-hydroxyvitamin D3 1alpha-hydroxylase (CYP27B1). J Steroid Biochem Mol Biol 2010; 119:171-9. [PMID: 20193763 DOI: 10.1016/j.jsbmb.2010.02.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 02/23/2010] [Accepted: 02/23/2010] [Indexed: 01/08/2023]
Abstract
CYP27B1 catalyzes the 1alpha-hydroxylation of 25-hydroxyvitamin D3 to 1alpha,25-dihydroxyvitamin D3, the hormonally active form of vitamin D3. To further characterize mouse CYP27B1, it was expressed in Escherichia coli, purified and its activity measured on substrates incorporated into phospholipid vesicles, which served as a model of the inner mitochondrial membrane. 25-Hydroxyvitamin D3 and 25-hydroxyvitamin D2 in vesicles underwent 1alpha-hydroxylation with similar kinetics, the catalytic rate constants (k(cat)) were 41 and 48mol/min/mol P450, respectively, while K(m) values were 5.9 and 4.6mmol/mol phospholipid, respectively. CYP27B1 showed inhibition when substrate concentrations in the membrane were greater than 4 times K(m), more pronounced with 25-hydroxyvitamin D3 than 25-hydroxyvitamin D2. Higher catalytic efficiency was seen in vesicles prepared from dioleoyl phosphatidylcholine and cardiolipin than for dimyristoyl phosphatidylcholine vesicles. CYP27B1 also catalyzed 1alpha-hydroxylation of vesicle-associated 24R,25-dihydroxyvitamin D3 and 20-hydroxyvitamin D3, and 25-hydroxylation of 1alpha-hydroxyvitamin D3 and 1alpha-hydroxyvitamin D2, but with much lower efficiency than for 25(OH)D3. This study shows that CYP27B1 can hydroxylate 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 associated with phospholipid membranes with the highest activity yet reported for the enzyme. The expressed enzyme has low activity at higher concentrations of 25-hydroxyvitamin D in membranes, revealing that substrate inhibition may contribute to the regulation of the activity of this enzyme.
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Affiliation(s)
- Edith K Y Tang
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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20
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Monooxygenases as biocatalysts: Classification, mechanistic aspects and biotechnological applications. J Biotechnol 2010; 146:9-24. [PMID: 20132846 DOI: 10.1016/j.jbiotec.2010.01.021] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 01/22/2010] [Accepted: 01/25/2010] [Indexed: 12/29/2022]
Abstract
Monooxygenases are enzymes that catalyze the insertion of a single oxygen atom from O(2) into an organic substrate. In order to carry out this type of reaction, these enzymes need to activate molecular oxygen to overcome its spin-forbidden reaction with the organic substrate. In most cases, monooxygenases utilize (in)organic cofactors to transfer electrons to molecular oxygen for its activation. Monooxygenases typically are highly chemo-, regio-, and/or enantioselective, making them attractive biocatalysts. In this review, an exclusive overview of known monooxygenases is presented, based on the type of cofactor that these enzymes require. This includes not only the cytochrome P450 and flavin-dependent monooxygenases, but also enzymes that utilize pterin, metal ions (copper or iron) or no cofactor at all. As most of these monooxygenases require nicotinamide coenzymes as electron donors, also an overview of current methods for coenzyme regeneration is given. This latter overview is of relevance for the biotechnological applications of these oxidative enzymes.
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Novikova LA, Faletrov YV, Kovaleva IE, Mauersberger S, Luzikov VN, Shkumatov VM. From structure and functions of steroidogenic enzymes to new technologies of gene engineering. BIOCHEMISTRY (MOSCOW) 2010; 74:1482-504. [DOI: 10.1134/s0006297909130057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Urushino N, Yasuda K, Ikushiro S, Kamakura M, Ohta M, Sakaki T. Metabolism of 1alpha,25-dihydroxyvitamin D2 by human CYP24A1. Biochem Biophys Res Commun 2009; 384:144-8. [PMID: 19393625 DOI: 10.1016/j.bbrc.2009.04.075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
Abstract
The metabolism of 1alpha,25-dihydroxyvitamin D2 (1alpha,25(OH)2D2) by human CYP24A1 was examined using the recombinant enzyme expressed in Escherichia coli cells. HPLC analysis revealed that human CYP24A1 produces at least 10 metabolites, while rat CYP24A1 produces only three metabolites, indicating a remarkable species-based difference in the CYP24A1-dependent metabolism of 1alpha,25(OH)2D2 between humans and rats. LC-MS analysis and periodate treatment of the metabolites strongly suggest that human CYP24A1 converts 1alpha,25(OH)2D2 to 1alpha,24,25,26(OH)4D2, 1alpha,24,25,28(OH)4D2, and 24-oxo-25,26,27-trinor-1alpha(OH)D2 via 1alpha,24,25(OH)3D2. These results indicate that human CYP24A1 catalyzes the C24-C25 bond cleavage of 1alpha,24,25(OH)2D2, which is quite effective in the inactivation of the active form of vitamin D2. The combination of hydroxylation at multiple sites and C-C bond cleavage could form a large number of metabolites. Our findings appear to be useful to predict the metabolism of vitamin D2 and its analogs in the human body.
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Affiliation(s)
- Naoko Urushino
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
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23
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Ramasamy I. Inherited disorders of calcium homeostasis. Clin Chim Acta 2008; 394:22-41. [PMID: 18474231 DOI: 10.1016/j.cca.2008.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 03/30/2008] [Accepted: 04/14/2008] [Indexed: 12/19/2022]
Abstract
In mammals a complicated homeostatic mechanism has evolved to maintain near consistency of extracellular calcium ion levels. The homeostatic mechanism involves several hormones, which comprise among others, parathyroid hormone and vitamin D. The recent resurge in vitamin D deficiency, as a global health issue, has increased interest in the hormone. In addition to vitamin D deficiency, other causes of rickets are calcium deficiency and inherited disorders of vitamin D and phosphorus metabolism. Vitamin D-resistant syndromes are caused by hereditary defects in metabolic activation of the hormone or by mutations in the vitamin D receptor, which binds the hormone with high affinity and regulates the expression of genes through zinc finger mediated DNA binding and protein-protein interaction. Current interest is to correlate the type/position of mutations that result in disorders of vitamin D metabolism or in vitamin D receptor function with the variable phenotypic features and clinical presentation. The calcium sensing receptor plays a key role in calcium homeostasis. Loss of function mutations in the calcium sensing receptor can cause familial benign hypocalciuric hypercalcemia in heterozygotes and neonatal severe hyperparathyroidism when homozygous mutations occur in the calcium sensing receptor. Gain of function mutation can cause the opposite effect causing autosomal dominant hypocalcemia. Mouse models using targeted gene disruption strategies have been valuable tools to study the effect of mutations on the calcium sensing receptor or in the vitamin D activation pathway. Dysfunctional calcium sensing receptors with function altering mutations may be responsive to treatment with allosteric modulators of the calcium sensing receptor. Vitamin D analogs which induce unusual structural conformations on the vitamin D receptor may have a variety of therapeutic indications. This review summarises recent advances in knowledge of the molecular pathology of inherited disorders of calcium homeostasis.
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Affiliation(s)
- Indra Ramasamy
- Department of Chemical Pathology, Dumfries and Galloway District Hospital, Bankend Road, Dumfries, UK.
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24
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Sawada N, Yamamoto K, Yamada S, Ikushiro S, Kamakura M, Ohta M, Inouye K, Sakaki T. Role of Gln 85 of human CYP27A1 in 25-hydroxyvitamin D(3)-binding and protein folding. Biochem Biophys Res Commun 2007; 355:211-6. [PMID: 17292862 DOI: 10.1016/j.bbrc.2007.01.158] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 01/26/2007] [Indexed: 11/23/2022]
Abstract
CYP27A1 catalyzes vitamin D(3) 25-hydroxylation and further hydroxylation at C-1alpha, C-24 or C-26(27). Molecular modeling of human CYP27A1 and docking with 25-hydroxyvitamin D(3) predicted that Gln 85 might be important for 1alpha-hydroxylation activity of CYP27A1 by forming a hydrogen bond with the 25-OH group of 25-hydroxyvitamin D(3). Expectedly, the mutant Q85H expressed in Escherichia coli showed no detectable 1alpha-hydroxylation activity toward 25-hydroxyvitamin D(3). In addition, Q85H prefers 24-hydroxylation toward 25-hydroxyvitamin D(3) whereas the wild-type prefers 26(27)-hydroxylation. A molecular modeling study also suggests that Gln 85 of CYP27A1 simultaneously interacts with Asn 107 and the hydroxyl group of the substrate. The fact that Q85L did not contain a heme molecule suggests that the hydrogen bond between Gln 85 and Asn 107 is important for protein folding of CYP27A1. Based on these results, it is possible that Gln 85 plays essential roles in both substrate-binding and protein folding.
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Affiliation(s)
- Natsumi Sawada
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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Shashkova TV, Luzikov VN, Novikova LA. Coexpression of all constituents of the cholesterol hydroxylase/lyase system in Escherichia coli cells. BIOCHEMISTRY (MOSCOW) 2006; 71:810-4. [PMID: 16903836 DOI: 10.1134/s0006297906070145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using the pTrc99A/P450scc vector, a plasmid was constructed in which cDNAs for cytochrome P450scc, adrenodoxin reductase, and adrenodoxin are situated in a single expression cassette. This plasmid was shown to direct the synthesis of all the above proteins in Escherichia coli. Their localization in the E. coli cells and stoichiometry were determined. Cell homogenates exhibited cholesterol hydroxylase/lyase activity, due to catalytically active forms of all three proteins. Thus, the full set of constituents of the mammalian cholesterol hydroxylase/lyase system was shown to be synthesized in bacterial cells for the first time.
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Affiliation(s)
- T V Shashkova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
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26
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Hannemann F, Virus C, Bernhardt R. Design of an Escherichia coli system for whole cell mediated steroid synthesis and molecular evolution of steroid hydroxylases. J Biotechnol 2006; 124:172-81. [PMID: 16504331 DOI: 10.1016/j.jbiotec.2006.01.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 11/16/2005] [Accepted: 01/04/2006] [Indexed: 11/28/2022]
Abstract
The 15beta-hydroxylase (CYP106A2) from Bacillus megaterium, one of the few bacterial steroid hydroxylases, which has been isolated and characterized so far, catalyses the 15beta-hydroxylation of a variety of steroids. The enzyme can be supported in its activity with adrenodoxin (Adx) and adrenodoxin reductase (AdR) from bovine adrenals, supplying this enzyme with the reducing equivalents necessary for steroid hydroxylation activity. This three-component electron transfer chain was implemented in Escherichia coli by coexpression of the corresponding coding sequences from two plasmids, containing different selection markers and compatible origins of replication. The cDNAs of AdR and Adx on the first plasmid were separated by a ribosome binding sequence, with the reductase preceding the ferredoxin. The second plasmid for CYP106A2 expression was constructed with all features necessary for a molecular evolution approach. The transformed bacteria show the inducible ability to efficiently convert 11-deoxycorticosterone (DOC) to 15beta-DOC at an average rate of 1 mM/d in culture volumes of 300 ml. The steroid conversion system was downscaled to the microtiter plate format and a robot set-up was developed for a fluorescence-based conversion assay as well as a CO difference spectroscopy assay, which enables the screening for enzyme variants with higher activity and stability.
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Affiliation(s)
- Frank Hannemann
- FR 8.3--Biochemie, Universität des Saarlandes, Saarbrücken, Germany
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Urushino N, Yamamoto K, Kagawa N, Ikushiro S, Kamakura M, Yamada S, Kato S, Inouye K, Sakaki T. Interaction between mitochondrial CYP27B1 and adrenodoxin: role of arginine 458 of mouse CYP27B1. Biochemistry 2006; 45:4405-12. [PMID: 16584176 DOI: 10.1021/bi060072o] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A molecular modeling study of CYP27B1 suggests that Arg458 of mouse CYP27B1 is involved in interaction with adrenodoxin (ADX). Thus, we generated CYP27B1 mutants R458K and R458Q and revealed their enzymatic properties. Substrate-induced difference spectra and K(m) values for 1alpha-hydroxylation of 25(OH)D3 indicate that the replacement of Arg458 with Lys or Gln does not affect substrate binding. However, these mutants showed remarkable decreases of both kcat values and the ratio of product formation to NADPH oxidation (coupling efficiency). A high K(m) value of R458Q for ADX concentration and a decrease of rate constant of the first electron transfer seem reasonable considering that the conversion from Arg to noncharged Gln abolishes salt-bridge formation with the acidic residue of ADX. On the other hand, R458K showed atypical kinetics for ADX concentration with Hill's constant of 2.0 and high catalytic activity at high ADX concentration by increase of coupling efficiency. These results suggest that conformational change of R458K by binding the two ADX molecules is essential for 1alpha-hydroxylation of 25(OH)D3. On the other hand, binding one ADX molecule is sufficient for the conformational change of the wild-type CYP27B1, judging from its Michaelis-Menten-type kinetics for ADX concentration with high coupling efficiency. These results suggest that ADX functions as an effector for the oxygen transfer reaction in addition to being an electron donor for CYP27B1.
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Affiliation(s)
- Naoko Urushino
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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Wu ZL, Bartleson CJ, Ham AJL, Guengerich FP. Heterologous expression, purification, and properties of human cytochrome P450 27C1. Arch Biochem Biophys 2006; 445:138-46. [PMID: 16360114 DOI: 10.1016/j.abb.2005.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 11/04/2005] [Accepted: 11/05/2005] [Indexed: 11/18/2022]
Abstract
Cytochrome P450 (P450) 27C1 is one of the "orphan" P450 enzymes without a known biological function. A human P450 27C1 cDNA with a nucleotide sequence modified for Escherichia coli usage was prepared and modified at the N-terminus, based on the expected mitochondrial localization. A derivative with residues 3-60 deleted was expressed at a level of 1350nmol/L E. coli culture and had the characteristic P450 spectra. The identity of the expressed protein was confirmed by mass spectrometry of proteolytic fragments. The purified P450 was in the low-spin iron state, and the spin equilibrium was not perturbed by any of the potential substrates vitamin D(3), 1alpha- or 25-hydroxy vitamin D(3), or cholesterol. P450s 27A1 and 27B1 are known to catalyze the 25-hydroxylation of vitamin D(3) and the 1alpha-hydroxylation of 25-hydroxy vitamin D(3), respectively. In the presence of recombinant human adrenodoxin and adrenodoxin reductase, recombinant P450 27C1 did not catalyze the oxidation of vitamin D(3), 1alpha- or 25-hydroxy vitamin D(3), or cholesterol at detectable rates. P450 27C1 mRNA was determined to be expressed in liver, kidney, pancreas, and several other human tissues.
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Affiliation(s)
- Zhong-Liu Wu
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
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Sakaki T, Inouye K. Practical application of mammalian cytochrome P450. J Biosci Bioeng 2005; 90:583-90. [PMID: 16232916 DOI: 10.1263/jbb.90.583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Accepted: 08/31/2000] [Indexed: 11/17/2022]
Abstract
Heterologous expression systems play an important role in the analysis of structure-function relationships of mammalian P450s. In addition, these expression systems allow practical application of mammalian P450s. Genetically engineered fused enzymes between mammalian P450 and yeast NADPH-P450 reductase have possible applications in bioconversion processes. Combined use of techniques reported thus far could produce steroid hormones in the recombinant yeast cells harboring four P450 species, CYP11A1, CYP17A1, CYP21B1 and CYP11B1. In an Escherichia coli expression system, the technology of the construction of the mitochondrial P450 electron transport chain has been established. The recombinant E. coli cells expressing CYP27B1, adrenodoxin and NADPH-adrenodoxin reductase would be applicable to a bioconversion process to produce 1alpha,25-dihydroxyvitamin D3. We also demonstrated the usefulness of heterologous expression systems for human liver microsomal P450s for the prediction of drug metabolism in the human body. Microsomal fractions prepared from recombinant yeast, insect and mammalian cells are commercially available and play an important role in preclinical drug development. Application of mammalian P450 to bioremediation with genetic engineering has also been developed. Thus, mammalian P450s appear to have great potential for a wide range of practical applications.
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Affiliation(s)
- T Sakaki
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Yamamoto K, Uchida E, Urushino N, Sakaki T, Kagawa N, Sawada N, Kamakura M, Kato S, Inouye K, Yamada S. Identification of the amino acid residue of CYP27B1 responsible for binding of 25-hydroxyvitamin D3 whose mutation causes vitamin D-dependent rickets type 1. J Biol Chem 2005; 280:30511-6. [PMID: 15972816 DOI: 10.1074/jbc.m505244200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously reported the three-dimensional structure of human CYP27B1 (25-hydroxyvitamin D3 1alpha-hydroxylase) constructed by homology modeling. Using the three-dimensional model we studied the docking of the substrate, 25-hydroxyvitamin D3, into the substrate binding pocket of CYP27B1. In this study, we focused on the amino acid residues whose point mutations cause vitamin D-dependent rickets type 1, especially unconserved residues among mitochondrial CYPs such as Gln65 and Thr409. Recently, we successfully overexpressed mouse CYP27B1 by using a GroEL/ES co-expression system. In a mutation study of mouse CYP27B1 that included spectroscopic analysis, we concluded that in a 1alpha-hydroxylation process, Ser408 of mouse CYP27B1 corresponding to Thr409 of human CYP27B1 forms a hydrogen bond with the 25-hydroxyl group of 25-hydroxyvitamin D3. This is the first report that shows a critical amino acid residue recognizing the 25-hydroxyl group of the vitamin D3.
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Affiliation(s)
- Keiko Yamamoto
- Institute of Biomaterials and Bioengineering & School of Biomedical Sciences, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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Kamao M, Hatakeyama S, Sakaki T, Sawada N, Inouye K, Kubodera N, Reddy GS, Okano T. Measurement and characterization of C-3 epimerization activity toward vitamin D3. Arch Biochem Biophys 2005; 436:196-205. [PMID: 15752725 DOI: 10.1016/j.abb.2005.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 01/07/2005] [Indexed: 11/15/2022]
Abstract
Recently, epimerization of the hydroxyl group at C-3 has been identified as a unique metabolic pathway of vitamin D compounds. We measured C-3 epimerization activity in subcellular fractions prepared from cultured cells and investigated the basic properties of the enzyme responsible for the epimerization. C-3 epimerization activity was detected using a NADPH-generating system containing glucose-6-phosphate, NADP, glucose-6-phosphate dehydrogenase, and Mg(2+). The highest level of activity was observed in a microsomal fraction prepared from rat osteoblastic UMR-106 cells but activity was also observed in microsomal fractions prepared from MG-63, Caco-2, Hep G2, and HUH-7 cells. In terms of maximum velocity (V(max)) and the Michaelis constant (K(m)), 25-hydroxyvitamin D(3) [25(OH)D(3)] exhibited the highest specificity for the epimerization at C-3 among 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], 25(OH)D(3), 24,25-dihydroxyvitamin D(3) [24,25(OH)(2)D(3)], and 22-oxacalcitriol (OCT). The epimerization activity was not inhibited by various cytochrome P450 inhibitors and antiserum against NADPH cytochrome P450 reductase. Neither CYP24, CYP27A1, CYP27B1 nor 3(alpha-->beta)hydroxysteroid epimerase (HSE) catalyzed the epimerization in vitro. Based on these results, the enzyme(s) responsible for the epimerization of vitamin D(3) at C-3 are thought to be located in microsomes and different from cytochrome P450 and HSE.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558, Japan
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Abe D, Sakaki T, Kusudo T, Kittaka A, Saito N, Suhara Y, Fujishima T, Takayama H, Hamamoto H, Kamakura M, Ohta M, Inouye K. METABOLISM OF 2α-PROPOXY-1α,25-DIHYDROXYVITAMIN D3AND 2α-(3-HYDROXYPROPOXY)-1α,25-DIHYDROXYVITAMIN D3BY HUMAN CYP27A1 AND CYP24A1. Drug Metab Dispos 2005; 33:778-84. [PMID: 15764712 DOI: 10.1124/dmd.104.003038] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recently, we demonstrated that some A-ring-modified vitamin D3 analogs had unique biological activity. Of these analogs, 2alpha-propoxy-1alpha,25(OH)2D3 (C3O1) and 2alpha-(3-hydroxypropoxy)-1alpha,25(OH)2D3 (O2C3) were examined for metabolism by CYP27A1 and CYP24A1. Surprisingly, CYP27A1 catalyzed the conversion from C3O1 to O2C3, which has 3 times more affinity for vitamin D receptor than C3O1. Thus, the conversion from C3O1 to O2C3 by CYP27A1 is considered to be a metabolic activation process. Five metabolites were detected in the metabolism of C3O1 and O2C3 by human CYP24A1 including both C-23 and C-24 oxidation pathways. On the other hand, three metabolites of the C-24 oxidation pathway were detected in their metabolism by rat CYP24A1, indicating a species-based difference in the CYP24A1-dependent metabolism of C3O1 and O2C3 between humans and rats. Kinetic analysis revealed that the Km and kcat values of human CYP24A1 for O2C3 are, respectively, approximately 16 times more and 3 times less than those for 1alpha,25(OH)2D3. Thus, the catalytic efficiency, kcat/Km, of human CYP24A1 for O2C3 is only 2% of 1alpha,25(OH)2D3. These results and a high calcium effect of C3O1 and O2C3 in animal experiments using rats suggest that C3O1 and O2C3 are promising for clinical treatment of osteoporosis.
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Affiliation(s)
- Daisuke Abe
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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Uchida E, Kagawa N, Sakaki T, Urushino N, Sawada N, Kamakura M, Ohta M, Kato S, Inouye K. Purification and characterization of mouse CYP27B1 overproduced by an Escherichia coli system coexpressing molecular chaperonins GroEL/ES. Biochem Biophys Res Commun 2004; 323:505-11. [PMID: 15369780 DOI: 10.1016/j.bbrc.2004.08.110] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Indexed: 11/15/2022]
Abstract
The expression of mouse CYP27B1 in Escherichia coli has been dramatically enhanced by coexpression of GroEL/ES. To reveal the enzymatic properties of CYP27B1, we measured its hydroxylation activity toward vitamin D3 and 1alpha-hydroxyvitamin D3 (1alpha(OH)D3) in addition to the physiological substrate 25(OH)D3. Surprisingly, CYP27B1 converted vitamin D3 to 1alpha,25(OH)D3. Both 1alpha-hydroxylation activity toward vitamin D3, and 25-hydroxylation activity toward 1alpha(OH)D3 were observed. The Km and Vmax values for 25-hydroxylation activity toward 1alpha(OH)D3 were estimated to be 1.7 microM and 0.51 mol/min/mol P450, respectively, while those for 1alpha-hydroxylation activity toward 25(OH)D3 were 0.050 microM and 2.73 mol/min/mol P450, respectively. Note that the substrate must be fixed in the opposite direction in the substrate-binding pocket of CYP27B1 between 1alpha-hydroxylation and 25-hydroxylation. Based on these results and the fact that human CYP27A1 and Streptomyces CYP105A1 also convert vitamin D3 to 1alpha,25(OH)D3, 1alpha-hydroxylation, and 25-hydroxylation of vitamin D3 appear to be closely linked together.
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Affiliation(s)
- Eriko Uchida
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Sawada N, Sakaki T, Yoneda S, Kusudo T, Shinkyo R, Ohta M, Inouye K. Conversion of vitamin D3 to 1alpha,25-dihydroxyvitamin D3 by Streptomyces griseolus cytochrome P450SU-1. Biochem Biophys Res Commun 2004; 320:156-64. [PMID: 15207715 DOI: 10.1016/j.bbrc.2004.05.140] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Indexed: 11/28/2022]
Abstract
Streptomyces griseolus cytochrome P450SU-1 (CYP105A1) was expressed in Escherichia coli at a level of 1.0 micromol/L culture and purified with a specific content of 18.0 nmol/mg protein. Enzymatic studies revealed that CYP105A1 had 25-hydroxylation activity towards vitamin D2 and vitamin D3. Surprisingly, CYP105A1 also showed 1alpha-hydroxylation activity towards 25(OH)D3. As mammalian mitochondrial CYP27A1 catalyzes a similar two-step hydroxylation towards vitamin D3, the enzymatic properties of CYP105A1 were compared with those of human CYP27A1. The major metabolite of vitamin D2 by CYP105A1 was 25(OH)D2, while the major metabolites by CYP27A1 were both 24(OH)D2 and 27(OH)D2. These results suggest that CYP105A1 recognizes both vitamin D2 and vitamin D3 in a similar manner, while CYP27A1 does not. The Km values of CYP105A1 for vitamin D2 25-hydroxylation, vitamin D3 25-hydroxylation, and 25-hydroxyvitamin D3 1alpha-hydroxylation were 0.59, 0.54, and 0.91 microM, respectively, suggesting a high affinity of CYP105A1 for these substrates.
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Affiliation(s)
- Natsumi Sawada
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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Kamao M, Tatematsu S, Sawada N, Sakaki T, Hatakeyama S, Kubodera N, Okano T. Cell specificity and properties of the C-3 epimerization of Vitamin D3 metabolites. J Steroid Biochem Mol Biol 2004; 89-90:39-42. [PMID: 15225744 DOI: 10.1016/j.jsbmb.2004.03.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is well documented that Vitamin D3 metabolites and synthetic analogs are metabolized to their epimers of the hydroxyl group at C-3 of the A-ring. We investigated the C-3 epimerization of Vitamin D3 metabolites in various cultured cells and basic properties of the enzyme responsible for the C-3 epimerization. 1alpha,25-Dihydroxyvitamin D3 [1alpha,25(OH)2D3], 25-hydroxyvitamin D3 [25(OH)D3] and 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] were metabolized to the respective C-3 epimers in UMR-106 (rat osteosarcoma), MG-63 (human osteosarcoma), Caco-2 (human colon adenocarcinoma), LLC-PK1 (porcine kidney) and HepG2 (human hepatoblastoma)] cells, although the differences existed in the amount of each C-3 epimer formed with different cell types. In terms of maximum velocity (Vmax) and Michaelis constant (Km) values for the C-3 epimerization in microsome fraction of UMR-106 cells, 25(OH)D3 exhibited the highest specificity for the C-3 epimerization among 1alpha,25(OH)2D3, 25(OH)D3 and 24,25(OH)2D3. C-3 epimerization activity was not inhibited by various cytochrome P450 inhibitors and antiserum against NADPH cytochrome P450 reductase. Neither CYP24, CYP27A1, CYP27B1 nor 3(alpha --> beta) -hydroxysteroid epimerase (HSE) catalyzed the C-3 epimerization in vitro. Based on these results, the enzyme responsible for the C-3 epimerization of Vitamin D3 are thought to be different from already-known cytochrome P450-related Vitamin D metabolic enzymes and HSE.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, 4-19-1 Motoyamakita-machi, Higashinada-ku, Kobe 658-8558, Japan
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Kamao M, Tatematsu S, Hatakeyama S, Sakaki T, Sawada N, Inouye K, Ozono K, Kubodera N, Reddy GS, Okano T. C-3 epimerization of vitamin D3 metabolites and further metabolism of C-3 epimers: 25-hydroxyvitamin D3 is metabolized to 3-epi-25-hydroxyvitamin D3 and subsequently metabolized through C-1alpha or C-24 hydroxylation. J Biol Chem 2004; 279:15897-907. [PMID: 14757768 DOI: 10.1074/jbc.m311473200] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, it was revealed that 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) and 24R,25-dihydroxyvitamin D3 (24,25(OH)2D3) were metabolized to their respective epimers of the hydroxyl group at C-3 of the A-ring. We now report the isolation and structural assignment of 3-epi-25-hydroxyvitamin D3 (3-epi-25(OH)D3 as a major metabolite of 25-hydroxyvitamin D3 (25(OH)D3) and the further metabolism of C-3 epimers of vitamin D3 metabolites. When 25(OH)D3 was incubated with various cultured cells including osteosarcoma, colon adenocarcinoma, and hepatoblastoma cell lines, 3-epi-25(OH)D3 and 24,25 (OH)2D3 were commonly observed as a major and minor metabolite of 25(OH)D3, respectively. 25(OH)D3 was at least as sensitive to C-3 epimerization as 1alpha, 25(OH)2D3 which has been reported as a substrate for the C-3 epimerization reaction. Unlike these cultured cells, LLC-PK1 cells, a porcine kidney cell line, preferentially produced 24,25(OH)2D3 rather than 3-epi-25(OH)D3. We also confirmed the existence of 3-epi-25(OH)D3 in the serum of rats intravenously given pharmacological doses of 25(OH)D3. The cultured cells metabolized 3-epi-25OHD3 and 3-epi-1alpha,25(OH)2D3 to 3-epi-24,25(OH)2D3 and 3-epi-1alpha,24,25(OH)3D3, respectively. In addition, we demonstrated that 3-epi-25(OH)D3 was metabolized to 3-epi-1alpha,25(OH)2D3 by CYP27B1 and to 3-epi-24,25(OH)2D3 by CYP24 using recombinant Escherichia coli cell systems. 3-Epi-25(OH)D3, 3-epi-1alpha,25(OH)2D3, and 3-epi-24,25(OH)2D3 were biologically less active than 25(OH)D3, 1alpha,25(OH)2D3, and 24,25(OH)2D3, but 3-epi-1alpha,25(OH)2D3 showed to some extent transcriptional activity toward target genes and anti-proliferative/differentiation-inducing activity against human myeloid leukemia cells (HL-60). These results indicate that C-3 epimerization may be a common metabolic pathway for the major metabolites of vitamin D3.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558, Japan
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Sakaki T, Sawada N, Abe D, Komai K, Shiozawa S, Nonaka Y, Nakagawa K, Okano T, Ohta M, Inouye K. Metabolism of 26,26,26,27,27,27-F6-1alpha,25-dihydroxyvitamin D3 by CYP24: species-based difference between humans and rats. Biochem Pharmacol 2003; 65:1957-65. [PMID: 12787875 DOI: 10.1016/s0006-2952(03)00190-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The compound 26,26,26,27,27,27-F(6)-1alpha,25(OH)(2)D(3) is a hexafluorinated analog of the active form of Vitamin D(3). The enhanced biological activity of F(6)-1alpha,25(OH)(2)D(3) is considered to be related to a decreased metabolic inactivation of the compound in target tissues such as the kidneys, small intestine, and bones. Our previous study demonstrated that CYP24 is responsible for the metabolism of F(6)-1alpha,25(OH)(2)D(3) in the target tissues. In this study, we compared the human and rat CYP24-dependent metabolism of F(6)-1alpha,25(OH)(2)D(3) by using the Escherichia coli expression system. In the recombinant E. coli cells expressing human CYP24, bovine adrenodoxin and NADPH-adrenodoxin reductase, F(6)-1alpha,25(OH)(2)D(3) was successively converted to F(6)-1alpha,23S,25(OH)(3)D(3), F(6)-23-oxo-1alpha,25(OH)(2)D(3), and the putative ether compound with the same molecular mass as F(6)-1alpha,25(OH)(2)D(3). The putative ether was not observed in the recombinant E. coli cells expressing rat CYP24. These results indicate species-based difference between human and rat CYP24 in the metabolism of F(6)-1alpha,25(OH)(2)D(3). In addition, the metabolite with a cleavage at the C(24)z.sbnd;C(25) bond of F(6)-1alpha,25(OH)(2)D(3) was detected as a minor metabolite in both human and rat CYP24. Although F(6)-1alpha,23S,25(OH)(3)D(3) and F(6)-23-oxo-1alpha,25(OH)(2)D(3) had a high affinity for Vitamin D receptor, the side-chain cleaved metabolite and the putative ether showed extremely low affinity for Vitamin D receptor. These findings indicate that human CYP24 has a dual pathway for metabolic inactivation of F(6)-1alpha,25(OH)(2)D(3) while rat CYP24 has only one pathway. Judging from the fact that metabolism of F(6)-1alpha,25(OH)(2)D(3) in rat CYP24-harboring E. coli cells is quite similar to that in the target tissues of rat, the metabolism seen in human CYP24-harboring E. coli cells appear to exhibit the same metabolism as in human target tissues. Thus, this recombinant system harboring human CYP24 appears quite useful for predicting the metabolism and efficacy of Vitamin D analogs in human target tissues before clinical trials.
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Affiliation(s)
- Toshiyuki Sakaki
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Japan.
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Araya Z, Hosseinpour F, Bodin K, Wikvall K. Metabolism of 25-hydroxyvitamin D3 by microsomal and mitochondrial vitamin D3 25-hydroxylases (CYP2D25 and CYP27A1): a novel reaction by CYP27A1. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1632:40-7. [PMID: 12782149 DOI: 10.1016/s1388-1981(03)00062-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The metabolism of 25-hydroxyvitamin D(3) was studied with a crude mitochondrial cytochrome P450 extract from pig kidney and with recombinant human CYP27A1 (mitochondrial vitamin D(3) 25-hydroxylase) and porcine CYP2D25 (microsomal vitamin D(3) 25-hydroxylase). The kidney mitochondrial cytochrome P450 catalyzed the formation of 1alpha,25-dihydroxyvitamin D(3), 24,25-dihydroxyvitamin D(3) and 25,27-dihydroxyvitamin D(3). An additional metabolite that was separated from the other hydroxylated products on HPLC was also formed. The formation of this 25-hydroxyvitamin D(3) metabolite was dependent on NADPH and the mitochondrial electron transferring protein components. A monoclonal antibody directed against purified pig liver CYP27A1 immunoprecipitated the 1alpha- and 27-hydroxylase activities towards 25-hydroxyvitamin D(3) as well as the formation of the unknown metabolite. These results together with substrate inhibition experiments indicate that CYP27A1 is responsible for the formation of the unknown 25-hydroxyvitamin D(3) metabolite in kidney. Recombinant human CYP27A1 was found to convert 25-hydroxyvitamin D(3) into 1alpha,25-dihydroxyvitamin D(3), 25,27-dihydroxyvitamin D(3) and a major metabolite with the same retention time on HPLC as that formed by kidney mitochondrial cytochrome P450. Gas chromatography-mass spectrometry (GC-MS) analysis of the unknown enzymatic product revealed it to be a triol different from other known hydroxylated 25-hydroxyvitamin D(3) metabolites such as 1alpha,25-, 23,25-, 24,25-, 25,26- or 25,27-dihydroxyvitamin D(3). The product had the mass spectrometic properties expected for 4beta,25-dihydroxyvitamin D(3). Recombinant porcine CYP2D25 converted 25-hydroxyvitamin D(3) into 1alpha,25-dihydroxyvitamin D(3) and 25,26-dihydroxyvitamin D(3). It can be concluded that both CYP27A1 and CYP2D25 are able to carry out multiple hydroxylations of 25-hydroxyvitamin D(3).
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Affiliation(s)
- Zufan Araya
- Division of Biochemistry, Department of Pharmaceutical Biosciences, University of Uppsala, Box 578, Husargatan 3, S-751 23 Uppsala, Sweden
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Omdahl JL, Bobrovnikova EV, Annalora A, Chen P, Serda R. Expression, structure-function, and molecular modeling of vitamin D P450s. J Cell Biochem 2003; 88:356-62. [PMID: 12520537 DOI: 10.1002/jcb.10366] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Although vitamin D(3) is a natural product of a sunlight-mediated process in the skin, the secosteroid's biological function is dependent upon specific cytochrome P450 enzymes that mediate the parent vitamin's bioactivation and inactivation. Cytochrome P450C1 (CYP27B1) is the regulatory rate-limiting enzyme that directs the bioactivation process through introduction of a C-1alpha hydroxyl group. The resultant 1,25-dihydroxyvitamin D(3) (1,25D) is the biologically active secosteroid hormone that directs the multitude of vitamin D-dependent actions involved with calcium homeostasis, cellular differentiation and growth, and the immune response. The circulating and cellular level of 1,25D is regulated through a coordinated process involving the hormone's synthesis and degradation. Central to the degradation and turnover of 1,25D is the regulatory multi-catalytic cytochrome P450C24 (CYP24) enzyme that directs the introduction of C-24R groups onto targeted 25-hydroxy substrates. Discussed in this article is the action of the rat CYP24 to catalyze the side-chain oxidation and cleavage of 25-hydroxylated vitamin D metabolites. Expression and characterization of purified recombinant rat CYP24 is discussed in light of mutations directed at the enzyme's active site.
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Affiliation(s)
- J L Omdahl
- Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131-5221, USA.
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Omdahl JL, Morris HA, May BK. Hydroxylase enzymes of the vitamin D pathway: expression, function, and regulation. Annu Rev Nutr 2002; 22:139-66. [PMID: 12055341 DOI: 10.1146/annurev.nutr.22.120501.150216] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vitamin D is a secosteroid that is metabolically activated and degraded through the actions of three cytochrome P450 hydroxylase enzymes. Bioactivation occurs through the sequential actions of cytochromes P450C25 and P450C1, resulting in synthesis of the pleiotropic hormone 1,25-dihydroxyvitamin D (1,25VD), which regulates over 60 genes whose actions include those associated with calcium homeostasis and immune responses as well as cellular growth, differentiation, and apoptosis. Inactivation of 1,25VD occurs by C23/C24 oxidation pathways that are catalyzed by the multifunctional cytochrome P450C24 enzyme. Both P450C1 and P450C24 are highly regulated enzymes whose differential expression is controlled in response to numerous cellular modulatory agents such as parathyroid hormone (PTH), calcitonin, interferon gamma, calcium, phosphorus, and pituitary hormones as well as the secosteroid hormone 1,25VD. Most thoroughly studied at the molecular level are the actions of PTH to upregulate P450C1 gene expression and 1,25VD to induce the expression of P450C24. The regulatory action of PTH is mediated through the protein kinase A pathway and involves the phosphorylation of transcription factors that function at the proximal promoter of the P450C1 gene. The upregulation of P450C24 by 1,25VD has both a rapid nongenomic and a slower genomic component that are functionally linked. The rapid response involves protein kinase C and mitogen-activated protein kinase (MAPK) pathways that direct the phosphorylation of nuclear transcription factors. The slower genomic actions are linked to the binding of 1,25VD to the vitamin D receptor (VDR) and the interaction of the VDR-1,25VD complex with its heterodimer partner retinoid-X-receptor and associated coactivators. The regulatory complex is assembled on vitamin D response elements in the proximal promoter of the P450C24 gene and functions to increase the transcription rate.
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Affiliation(s)
- John L Omdahl
- Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, New Mexico 87131-5221, USA.
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Inouye K, Sakaki T. Enzymatic studies on the key enzymes of vitamin D metabolism; 1 alpha-hydroxylase (CYP27B1) and 24-hydroxylase (CYP24). BIOTECHNOLOGY ANNUAL REVIEW 2002; 7:179-94. [PMID: 11686044 DOI: 10.1016/s1387-2656(01)07037-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The key enzymes of vitamin D3 metabolism, renal 25-hydroxyvitamin D3 1 alpha-hydroxylase (CYP27B1) and 24-hydroxylase (CYP24) were expressed in Escherichia coli, and their enzymatic properties were revealed. As expected, mouse CYP27B1 and human CYP27B1 showed the 1 alpha-hydroxylation of 25-hydroxyvitamin D3 with the Michaelis constant, Km, value of 2.7 microM. Unexpectedly, both mouse CYP27B1 and human CYP27B1 showed greater Vmax/Km values toward 24,25-dihydroxyvitamin D3 than 25-hydroxyvitamin D3, suggesting that 24, 25-dihydroxyvitamin D3 is a better substrate than 25-hydroxyvitamin D3 for both CYP27B1. Enzymatic studies on substrate specificity of CYP27B1 revealed that 25-hydroxyl group of vitamin D3 was essential for the 1 alpha-hydroxylase activity, and 24-hydroxyl group enhanced the activity, but, 23-hydroxyl group greatly reduced the activity. On rat CYP24, it was demonstrated that CYP24 catalyzed four-step monooxygenation towards 25-hydroxyvitamin D3. Furthermore, in vivo and in vitro metabolic studies on 1 alpha,25-dihydroxyvitamin D3 clearly indicated that CYP24 catalyzed six-step monooxygenation to convert 1 alpha,25-dihydroxyvitamin D3 into calcitroic acid which is known as a final metabolite of 1 alpha,25-dihydroxyvitamin D3 for excretion in bile. These results strongly suggest that CYP24 is highly responsible for the metabolism of both 25-hydroxyvitamin D3 and 1 alpha,25-dihydroxyvitamin D3. In addition, we have succeeded in the construction of mitochondrial P450 electron transport chain consisting of ADR, ADX and each of CYP27B1 and CYP24 in E. coli cells. The coexpression system with CYP27B1 might be useful as a bioreactor to produce 1 alpha,25-dihydroxyvitamin D3. In contrast, the coexpression system with CYP24 would be applied to metabolic studies of vitamin D analogs used as drugs.
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Affiliation(s)
- K Inouye
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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Saint-Arnaud R, Dardenne O, Glorieux FH. Étiologie moléculaire des rachitismes vitamino-dépendants héréditaires. Med Sci (Paris) 2001. [DOI: 10.1051/medsci/200117121289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sawada N, Sakaki T, Kitanaka S, Kato S, Inouye K. Structure-function analysis of CYP27B1 and CYP27A1. Studies on mutants from patients with vitamin D-dependent rickets type I (VDDR-I) and cerebrotendinous xanthomatosis (CTX). EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:6607-15. [PMID: 11737215 DOI: 10.1046/j.0014-2956.2001.02615.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have determined eight types of missense mutants of CYP27B1 from Japanese vitamin D-dependent rickets type I (VDDR-I) patients [Kitanaka, S., Takeyama, K., Murayama, A., Sato, T., Okumura, K., Nogami, M., Hasegawa, Y., Niimi, H., Yanagisawa, J., Tanaka, T. & Kato, S. (1998) New England J. Med., 338, 653-661 and Kitanaka, S., Murayama, A., Sakaki, T., Inouye, K., Seino, Y., Fukumoto, S., Shima, M., Yukizane, S., Takayanagi, M., Niimi, H., Takeyama, K. & Kato, S. (1999) J. Clin. Endocrine Metab., 84, 4111-4117]. None of the CYP27B1 mutants showed 1alpha-hydroxylase activity towards 25-hydroxyvitamin D3. Thus, it was assumed that the mutated amino-acid residues play important roles in the 1alpha-hydroxylase activity, such as substrate binding, activation of molecular oxygen, interaction with adrenodoxin, and folding of the cytochrome P450 structure. To examine our hypothesis, we generated various mutants of CYP27B1 and studied their enzymatic properties. In addition, the corresponding mutations were introduced to CYP27A1, which belongs to the same family as CYP27B1. As CYP27A1 showed much higher expression level than CYP27B1 in Escherichia coli, further analysis including heme-binding and substrate-binding was performed with CYP27A1 in place of CYP27B1. Western blot analysis, spectral analysis including reduced CO-difference spectra and substrate-induced difference spectra, and enzymatic analysis of the mutant CYP27A1 gave information on the structure-function relationships of both CYP27A1 and CYP27B1. Although the sequence alignment suggested that Arg107, Gly125, and Pro497 of CYP27B1 might be involved in substrate binding, the experimental data strongly suggested that mutations of these amino-acid residues destroyed the tertiary structure of the substrate-heme pocket. It was also suggested that Arg389 and Arg453 of CYP27B1 were involved in heme-propionate binding, and Asp164 stabilized the four-helix bundle consisting of D, E, I and J helices, possibly by forming a salt bridge. Thr321 was found to be responsible for the activation of molecular oxygen.
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Affiliation(s)
- N Sawada
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan
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Yang W, Zhang L, Lu Z, Tao W, Zhai Z. A new method for protein coexpression in Escherichia coli using two incompatible plasmids. Protein Expr Purif 2001; 22:472-8. [PMID: 11483011 DOI: 10.1006/prep.2001.1453] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is commonly believed that incompatible plasmids carrying the same replicon cannot coexist stably in one Escherichia coli cell. However, we found that two incompatible plasmids carrying different antibiotic resistance genes, if under the selection pressure of the two antibiotics, can coexist in E. coli for at least 14 h, which is adequate for routine culture and protein expression. Based on this discovery, we developed a new method to coexpress foreign proteins in E. coli using two incompatible plasmids. The coding regions of the two subunits (DFF45 and DFF40) of the human DNA fragmentation factor (DFF) were cloned into two incompatible bacterial expression vectors-pET-21a with ampicillin resistance and pET-28a with kanamycin resistance, respectively. The two resulting plasmids were used to cotransform E. coli BL21(DE3) cells. After selection by ampicillin and kanamycin simultaneously, cotransformants that contain both recombinant plasmids were obtained. Induced by isopropyl beta-d-thiogalactoside, DFF45, and DFF40 were coexpressed efficiently in the presence of the two antibiotics. The coexpression product contained adequate soluble portions for both DFF45 and DFF40, while all DFF40 was insoluble if expressed alone. The coexpression product also exhibited the same caspase-activated DNase activity as its natural counterparts, which cannot be obtained if its two subunits are expressed separately.
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Affiliation(s)
- W Yang
- College of Life Sciences, Peking University, Beijing 100871, People's Republic of China
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Inouye K, Kondo S, Yamamura M, Nakanishi D, Sakaki T. Inhibitory effects of detergents on rat CYP1A1-dependent monooxygenase: comparison of mixed and fused systems consisting of rat CYP 1A1 and yeast NADPH-P450 reductase. Biochem Biophys Res Commun 2001; 280:1346-51. [PMID: 11162677 DOI: 10.1006/bbrc.2001.4293] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inhibitory effects of detergents Triton X-100 and Chaps on 7-ethoxycoumarin O-deethylation activity were examined in the recombinant microsomes containing both rat CYP1A1 and yeast NADPH-P450 reductase (the mixed system) and their fused enzyme (the fused system). Triton X-100 showed competitive inhibition in both mixed and fused systems with K(i) values of 24.6 and 21.5 microM, respectively. These results strongly suggest that Triton X-100 binds to the substrate-binding pocket of CYP1A1. These K(i) values are far below the critical micelle concentration of Triton X-100 (240 microM). Western blot analysis revealed no disruption of the microsomal membrane by Triton X-100 in the presence of 0-77 microM Triton X-100. On the other hand, Chaps gave distinct inhibitory effects to the mixed and fused systems. In the fused system, a mixed-type inhibition was observed with K(i) and K(i)' values of 1.2 and 5.4 mM of Chaps, respectively. However, in the mixed system, multiple inhibition modes by Chaps were observed. Western blot analysis revealed that the solubilized fused enzyme by Chaps preserved the activity whereas the solubilized CYP1A1 and NADPH-P450 reductase reductase showed no activity in the mixed system. Thus, the comparison of the mixed and fused systems appears quite useful to elucidate inhibition mechanism of detergents.
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Affiliation(s)
- K Inouye
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan.
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Sakaki T, Sawada N, Komai K, Shiozawa S, Yamada S, Yamamoto K, Ohyama Y, Inouye K. Dual metabolic pathway of 25-hydroxyvitamin D3 catalyzed by human CYP24. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:6158-65. [PMID: 11012668 DOI: 10.1046/j.1432-1327.2000.01680.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human 25-hydroxyvitamin D3 (25(OH)D3) 24-hydroxylase (CYP24) cDNA was expressed in Escherichia coli, and its enzymatic and spectral properties were revealed. The reconstituted system containing the membrane fraction prepared from recombinant E. coli cells, adrenodoxin and adrenodoxin reductase was examined for the metabolism of 25(OH)D3, 1alpha,25(OH)2D3 and their related compounds. Human CYP24 demonstrated a remarkable metabolism consisting of both C-23 and C-24 hydroxylation pathways towards both 25(OH)D3 and 1alpha,25(OH)2D3, whereas rat CYP24 showed almost no C-23 hydroxylation pathway [Sakaki, T. Sawada, N. Nonaka, Y. Ohyama, Y. & Inouye, K. (1999) Eur. J. Biochem. 262, 43-48]. HPLC analysis and mass spectrometric analysis revealed that human CYP24 catalyzed all the steps of the C-23 hydroxylation pathway from 25(OH)D3 via 23S, 25(OH)2D3, 23S,25,26(OH)3D3 and 25(OH)D3-26,23-lactol to 25(OH)D3-26, 23-lactone in addition to the C-24 hydroxylation pathway from 25(OH)D3 via 24R,25(OH)2D3, 24-oxo-25(OH)D3, 24-oxo-23S,25(OH)2D3 to 24,25,26,27-tetranor-23(OH)D3. On 1alpha,25(OH)2D3 metabolism, similar results were observed. These results strongly suggest that the single enzyme human CYP24 is greatly responsible for the metabolism of both 25(OH)D3 and 1alpha,25(OH)2D3. We also succeeded in the coexpression of CYP24, adrenodoxin and NADPH-adrenodoxin reductase in E. coli. Addition of 25(OH)D3 to the recombinant E. coli cell culture yielded most of the metabolites in both the C-23 and C-24 hydroxylation pathways. Thus, the E. coli expression system for human CYP24 appears quite useful in predicting the metabolism of vitamin D analogs used as drugs.
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Affiliation(s)
- T Sakaki
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan
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Sawada N, Sakaki T, Ohta M, Inouye K. Metabolism of vitamin D(3) by human CYP27A1. Biochem Biophys Res Commun 2000; 273:977-84. [PMID: 10891358 DOI: 10.1006/bbrc.2000.3050] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human vitamin D(3) 25-hydroxylase (CYP27A1) cDNA was expressed in Escherichia coli, and its enzymatic properties were revealed. The reconstituted system containing the membrane fraction prepared from the recombinant E. coli cells was examined for the metabolism of vitamin D(3). Surprisingly, at least eight forms of metabolites including the major product 25(OH)D(3) were observed. HPLC analysis and mass spectrometric analysis suggested that those metabolites were 25(OH)D(3), 26(OH)D(3), 27(OH)D(3), 24R,25(OH)(2)D(3), 1alpha, 25(OH)(2)D(3, )25,26(OH)(2)D(3) (25,27(OH)(2)D(3)), 27-oxo-D(3) and a dehydrogenated form of vitamin D(3). These results suggest that human CYP27A1 catalyzes multiple reactions and multiple-step metabolism toward vitamin D(3). The K(m) and V(max) values for vitamin D(3) 25-hydroxylation and 25(OH)D(3) 1alpha-hydroxylation were estimated to be 3.2 microM and 0.27 (mol/min/mol P450), and 3.5 microM and 0.021 (mol/min/mol P450), respectively. These kinetic studies have made it possible to evaluate a physiological meaning of each reaction catalyzed by CYP27A1.
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Affiliation(s)
- N Sawada
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
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