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Jasuja R, Spencer D, Jayaraj A, Peng L, Krishna M, Lawney B, Patel P, Jayaram B, Thayer KM, Beveridge DL, Bhasin S. Estradiol induces allosteric coupling and partitioning of sex-hormone-binding globulin monomers among conformational states. iScience 2021; 24:102414. [PMID: 34041454 PMCID: PMC8144348 DOI: 10.1016/j.isci.2021.102414] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/13/2021] [Accepted: 04/07/2021] [Indexed: 11/24/2022] Open
Abstract
Sex-hormone-binding globulin (SHBG) regulates the transport and bioavailability of estradiol. The dynamics of estradiol's binding to SHBG are incompletely understood, although it is believed that estradiol binds to each monomer of SHBG dimer with identical affinity (Kd ∼2 nM). Contrary to the prevalent view, we show that estradiol's binding to SHBG is nonlinear, and the "apparent" Kd changes with varying estradiol and SHBG concentrations. Estradiol's binding to each SHBG monomer influences residues in the ligand-binding pocket of both monomers and differentially alters the conformational and energy landscapes of both monomers. Monomers are not energetically or conformationally equivalent even in fully bound state. Estradiol's binding to SHBG involves bidirectional, inter-monomeric allostery that changes the distribution of both monomers among various energy and conformational states. Inter-monomeric allostery offers a mechanism to extend the binding range of SHBG and regulate hormone bioavailability as estradiol concentrations vary widely during life.
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Affiliation(s)
- Ravi Jasuja
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Function Promoting Therapies, Waltham, MA, USA
| | - Daniel Spencer
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Abhilash Jayaraj
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology, New Delhi, 110 016 India
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - Liming Peng
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Meenakshi Krishna
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Brian Lawney
- Center for Cancer Computational Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Function Promoting Therapies, Waltham, MA, USA
| | - Priyank Patel
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Bhyravabhotla Jayaram
- Supercomputing Facility for Bioinformatics and Computational Biology, Indian Institute of Technology, New Delhi, 110 016 India
| | - Kelly M. Thayer
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - David L. Beveridge
- Departments of Chemistry, Molecular Biology, and Biochemistry and Molecular Biophysics Program, Wesleyan University, Middletown, CT, USA
| | - Shalender Bhasin
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Holmboe SA, Jasuja R, Lawney B, Priskorn L, Joergensen N, Linneberg A, Jensen TK, Skakkebæk NE, Juul A, Andersson AM. Free testosterone and cardiometabolic parameters in men: comparison of algorithms. Endocr Connect 2021; 10:220-229. [PMID: 33544092 PMCID: PMC7983478 DOI: 10.1530/ec-20-0552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/04/2021] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Calculating the free testosterone level has gained increasing interest and different indirect algorithms have been suggested. The objective was to compare free androgen index (FAI), free testosterone estimated using the linear binding model (Vermeulen: cFTV) and the binding framework accounting for allosterically coupled SHBG monomers (Zakharov: cFTZ) in relation to cardiometabolic conditions. DESIGN A prospective cohort study including 5350 men, aged 30-70 years, participating in population-based surveys (MONICA I-III and Inter99) from 1982 to 2001 and followed until December 2012 with baseline and follow-up information on cardiometabolic parameters and vital status. RESULTS Using age-standardized hormone levels, FAI was higher among men with baseline cardiometabolic conditions, whereas cFTV and cFTZ levels were lower compared to men without these conditions as also seen for total testosterone. Men in highest quartiles of cFTV or cFTZ had lower risk of developing type 2 diabetes (cFTV: HR = 0.74 (0.49-1.10), cFTZ: HR = 0.59 (0.39-0.91)) than men in lowest quartile. In contrast, men with highest levels of FAI had a 74% (1.17-2.59) increased risk of developing type 2 diabetes compared to men in lowest quartile. CONCLUSION The association of estimated free testosterone and the studied outcomes differ depending on algorithm used. cFTV and cFTZ showed similar associations to baseline and long-term cardiometabolic parameters. In contrast, an empiric ratio, FAI, showed opposite associations to several of the examined parameters and may reflect limited clinical utility.
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Affiliation(s)
- Stine A Holmboe
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ravi Jasuja
- Research Program in Men’s Health: Aging and Metabolism, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Brian Lawney
- Research Program in Men’s Health: Aging and Metabolism, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Lærke Priskorn
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Niels Joergensen
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Allan Linneberg
- Centre for Clinical Research and Prevention, Frederiksberg Hospital, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tina Kold Jensen
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Environmental Medicine, Institute of Public Health, University of Southern Denmark, Odense, Denmark
| | - Niels Erik Skakkebæk
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anders Juul
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anna-Maria Andersson
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Blegdamsvej, Copenhagen, Denmark
- The International Research Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Correspondence should be addressed to A-M Andersson:
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Deswal R, Narwal V, Dang AS, Pundir C. An ultrasensitive electrochemical immunosensor for detection of sex hormone binding globulin. Microchem J 2019. [DOI: 10.1016/j.microc.2019.104010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Goldman AL, Bhasin S, Wu FCW, Krishna M, Matsumoto AM, Jasuja R. A Reappraisal of Testosterone's Binding in Circulation: Physiological and Clinical Implications. Endocr Rev 2017; 38:302-324. [PMID: 28673039 PMCID: PMC6287254 DOI: 10.1210/er.2017-00025] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 06/23/2017] [Indexed: 02/07/2023]
Abstract
In the circulation, testosterone and other sex hormones are bound to binding proteins, which play an important role in regulating their transport, distribution, metabolism, and biological activity. According to the free hormone hypothesis, which has been debated extensively, only the unbound or free fraction is biologically active in target tissues. Consequently, accurate determination of the partitioning of testosterone between bound and free fractions is central to our understanding of how its delivery to the target tissues and biological activity are regulated and consequently to the diagnosis and treatment of androgen disorders in men and women. Here, we present a historical perspective on the evolution of our understanding of the binding of testosterone to circulating binding proteins. On the basis of an appraisal of the literature as well as experimental data, we show that the assumptions of stoichiometry, binding dynamics, and the affinity of the prevailing models of testosterone binding to sex hormone-binding globulin and human serum albumin are not supported by published experimental data and are most likely inaccurate. This review offers some guiding principles for the application of free testosterone measurements in the diagnosis and treatment of patients with androgen disorders. The growing number of testosterone prescriptions and widely recognized problems with the direct measurement as well as the computation of free testosterone concentrations render this critical review timely and clinically relevant.
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Affiliation(s)
- Anna L Goldman
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Shalender Bhasin
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Frederick C W Wu
- Andrology Research Unit, Centre for Endocrinology and Diabetes, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Meenakshi Krishna
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Alvin M Matsumoto
- Geriatric Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, Washington 98108
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington 98104
| | - Ravi Jasuja
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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Zheng X, Bi C, Brooks M, Hage DS. Analysis of Hormone-Protein Binding in Solution by Ultrafast Affinity Extraction: Interactions of Testosterone with Human Serum Albumin and Sex Hormone Binding Globulin. Anal Chem 2015; 87:11187-94. [PMID: 26484387 DOI: 10.1021/acs.analchem.5b03007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ultrafast affinity extraction was used to study hormone-protein interactions in solution, using testosterone and its transport proteins human serum albumin (HSA) and sex hormone binding globulin (SHBG) as models. Both single column and two-dimensional systems based on HSA microcolumns were utilized to measure the free fraction of testosterone in hormone/protein mixtures at equilibrium or that were allowed to dissociate for various lengths of time. These data were used to determine the association equilibrium constants (Ka) or global affinities (nKa') and dissociation rate constants (kd) for testosterone with soluble HSA and SHBG. This method was also used to measure simultaneously the free fraction of testosterone and its equilibrium constants with both these proteins in physiological mixtures of these agents. The kd and Ka values obtained for HSA were 2.1-2.2 s(-1) and 3.2-3.5 × 10(4) M(-1) at pH 7.4 and 37 °C. The corresponding constants for SHBG were 0.053-0.058 s(-1) and 0.7-1.2 × 10(9) M(-1). All of these results gave good agreement with literature values, indicating that this approach could provide information on a wide range of rate constants and binding strengths for hormone-protein interactions in solution and at clinically relevant concentrations. The same method could be extended to alternative hormone-protein systems or other solutes and binding agents.
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Affiliation(s)
- Xiwei Zheng
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
| | - Cong Bi
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
| | - Marissa Brooks
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
| | - David S Hage
- Department of Chemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
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Thaler MA, Seifert-Klauss V, Luppa PB. The biomarker sex hormone-binding globulin - from established applications to emerging trends in clinical medicine. Best Pract Res Clin Endocrinol Metab 2015; 29:749-60. [PMID: 26522459 DOI: 10.1016/j.beem.2015.06.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Sex hormone-binding globulin (SHBG) is a serum glycoprotein exhibiting the unique feature of binding sex steroids with high affinity and specificity. Its serum levels are regulated not only by androgens and estrogens but also by thyroid hormones and other metabolic factors. Several disease conditions are accompanied by altered SHBG levels such as hyper- and hypoandrogenism, thyroid disorders, pituitary diseases, liver disorders, and breast as well as prostate cancer. Additionally, several drugs and alcohol consumption influence serum concentrations of SHBG. In some cases, altered SHBG levels are a specific result of the underlying pathology. In others, they merely constitute an epiphenomenon, which still might offer the possibility of using serum measurements of SHBG as surrogate marker. This review article portrays the different disorders associated with altered SHBG levels and discusses the usefulness of SHBG as disease biomarker from a clinicians as well as from an endocrinological researchers point of view.
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Affiliation(s)
- Markus A Thaler
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der TU München, Ismaninger Str. 22, 81675 München, Germany.
| | - Vanadin Seifert-Klauss
- Frauenklinik und Poliklinik, Klinikum rechts der Isar der TU München, Ismaninger Str. 22, 81675 München, Germany.
| | - Peter B Luppa
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der TU München, Ismaninger Str. 22, 81675 München, Germany.
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Zakharov MN, Bhasin S, Travison TG, Xue R, Ulloor J, Vasan RS, Carter E, Wu F, Jasuja R. A multi-step, dynamic allosteric model of testosterone's binding to sex hormone binding globulin. Mol Cell Endocrinol 2015; 399:190-200. [PMID: 25240469 DOI: 10.1016/j.mce.2014.09.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 08/03/2014] [Accepted: 09/01/2014] [Indexed: 12/01/2022]
Abstract
PURPOSE Circulating free testosterone (FT) levels have been used widely in the diagnosis and treatment of hypogonadism in men. Due to experimental complexities in FT measurements, the Endocrine Society has recommended the use of calculated FT (cFT) as an appropriate approach for estimating FT. We show here that the prevailing model of testosterone's binding to SHBG, which assumes that each SHBG dimer binds two testosterone molecules and that the two binding sites on SHBG have similar binding affinity is erroneous and provides FT values that differ substantially from those obtained using equilibrium dialysis. METHODS We characterized testosterone's binding to SHBG using binding isotherms, ligand depletion curves, and isothermal titration calorimetry (ITC). We derived a new model of testosterone's binding to SHBG from these experimental data and used this model to determine FT concentrations and compare these values with those derived from equilibrium dialysis. RESULTS Experimental data on testosterone's association with SHBG generated using binding isotherms including equilibrium binding, ligand depletion experiments, and ITC provide evidence of a multi-step dynamic process, encompassing at least two inter-converting microstates in unliganded SHBG, readjustment of equilibria between unliganded states upon binding of the first ligand molecule, and allosteric interaction between two binding sites of SHBG dimer. FT concentrations in men determined using the new multistep dynamic model with complex allostery did not differ from those measured using equilibrium dialysis. Systematic error in calculated FT vales in females using Vermeulen's model was also significantly reduced. In European Male Aging Study, the men deemed to have low FT (<2.5th percentile) by the new model were at increased risk of sexual symptoms and elevated LH. CONCLUSION Testosterone's binding to SHBG is a multi-step dynamic process that involves complex allostery within SHBG dimer. FT values obtained using the new model have close correspondence with those measured using equilibrium dialysis.
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Affiliation(s)
- Mikhail N Zakharov
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Shalender Bhasin
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA.
| | - Thomas G Travison
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ran Xue
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Jagadish Ulloor
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ramachandran S Vasan
- Sections of Preventative Medicine and Cardiology, Boston University School of Medicine, 761 Harrison Court, Boston, MA 02118, USA
| | - Emma Carter
- Andrology Research Unit, Manchester Academic Health Science Centre, Manchester Royal Infirmary, The University of Manchester, Manchester, UK
| | - Frederick Wu
- Andrology Research Unit, Manchester Academic Health Science Centre, Manchester Royal Infirmary, The University of Manchester, Manchester, UK
| | - Ravi Jasuja
- Section of Endocrinology, Diabetes, and Nutrition, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA.
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8
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Heinrich-Balard L, Zeinyeh W, Déchaud H, Rivory P, Roux A, Pugeat M, Cohen R. Inverse relationship between hSHBG affinity for testosterone and hSHBG concentration revealed by surface plasmon resonance. Mol Cell Endocrinol 2015; 399:201-7. [PMID: 25308967 DOI: 10.1016/j.mce.2014.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 11/30/2022]
Abstract
A wide range of human sex hormone-binding globulin (hSHBG) affinity constants for testosterone (KA_hSHBG) has been reported in literature. To bring new insight on the KA_hSHBG value, we implemented a study of the molecular interactions occurring between testosterone and its plasma transport proteins by using surface plasmon resonance. The immobilization on the sensorchip of a testosterone derivative was performed by an oligoethylene glycol linker. For different plasmas with hSHBG concentrations, an assessment of the KA_hSHBG was obtained from a set of sensorgrams and curve-fitting these data. We observed that KA_hSHBG decreased, from at least two decades, when the plasma hSHBG concentration increased from 4.4 to 680 nmol/L. Our study shows a wide biological variability of KA_hSHBG that is related to the hSHBG concentration. These unexpected results may have a physiological significance and question the validity of current methods that are recommended for calculating free testosterone concentrations to evaluate androgen disorders in humans.
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Affiliation(s)
- Laurence Heinrich-Balard
- Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France.
| | - Wael Zeinyeh
- Université de Lyon, Lyon F-69000, France; Groupement Hospitalier Est, Centre de Biologie Est, Laboratoire d'Hormonologie, Hospices Civils de Lyon, Bron 69677, France
| | - Henri Déchaud
- Université de Lyon, Lyon F-69000, France; Groupement Hospitalier Est, Centre de Biologie Est, Laboratoire d'Hormonologie, Hospices Civils de Lyon, Bron 69677, France; INSERM U1060 CarMeN, France
| | - Pascaline Rivory
- Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France
| | - Amandine Roux
- Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France
| | - Michel Pugeat
- Université de Lyon, Lyon F-69000, France; INSERM U1060 CarMeN, France
| | - Richard Cohen
- Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France; Hôpital Edouard Herriot, Laboratoire de Biochimie et de Biologie Moléculaire, Hospices Civils de Lyon, cedex 03, Lyon 69437, France
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Steroid binding properties of the 2nd WHO International Standard for sex hormone-binding globulin. Clin Chem Lab Med 2011; 49:869-72. [DOI: 10.1515/cclm.2011.146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Luppa PB, Metzger J, Schneider H. Surface plasmon resonance biosensorics in urine proteomics. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2010; 641:193-221. [PMID: 20407949 DOI: 10.1007/978-1-60761-711-2_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Surface plasmon resonance (SPR) is a novel biophysical detection method. In combination with sophisticated surface chemistries and sensing instrumentations, SPR biosensors are approved as tools for molecular interaction studies. SPR plays also a role in interaction proteomics. Once being detected in urine, SPR helps to unravel the functions of new proteins. Due to its outstanding analytical characteristics, SPR also moves more and more into the realm of quantitative analyses in the clinical laboratory. Complex urine determinations of proteins and/or metabolites will bring the SPR biosensor both to the core lab and to point-of-care-testing.This review delineates first the optical phenomena of SPR near to the gold surface, and also the main features of bioconjugation chemistry on a solid-state surface. Then the kinetic calculation of molecular interaction analysis using SPR is introduced. In order to portray the capability of the method, new applications in urine proteomics and proteinuria diagnostics are finally described in detail.
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Affiliation(s)
- Peter B Luppa
- Institut für Klinische Chemie, Krankenhaus München Rechts der Isar, München, Germany
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Mazer NA. A novel spreadsheet method for calculating the free serum concentrations of testosterone, dihydrotestosterone, estradiol, estrone and cortisol: with illustrative examples from male and female populations. Steroids 2009; 74:512-9. [PMID: 19321131 DOI: 10.1016/j.steroids.2009.01.008] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/25/2009] [Accepted: 01/27/2009] [Indexed: 10/21/2022]
Abstract
In humans, testosterone (T), dihydrotestosterone (DHT), estradiol (E2), estrone (E1) and cortisol (C) bind to the serum proteins sex hormone-binding globulin (SHBG), albumin (Alb) and corticosteroid-binding globulin (CBG). Equilibrium dialysis is considered to be the "gold standard" for measuring the free concentrations of these steroids but is technically difficult and not widely available. Based on a mathematical model of the 5-ligand/3-protein binding equilibria, we developed a novel spreadsheet method for calculating the free and bioavailable (free+Alb-bound) concentrations of each steroid in terms of the total steroid and protein concentrations. The model uses 15 association constants K(SHBG-X), K(Alb-X), and K(CBG-X) (X=T, DHT, E2, E1 and C) that have been estimated from a systematic review of published binding studies. The computation of the free and bioavailable concentrations uses an iterative numerical method that can be readily programmed on a spreadsheet. The method is illustrated with six examples corresponding to young men (YM), old men (OM), obese men (Ob M), young women (YM), pregnant women in the 3rd trimester (Preg T3) and oophorectomized women on oral conjugated equine estrogens (CEE). The resulting free hormone concentrations for YM and YW fall within the normal references ranges obtained by equilibrium dialysis for all five hormones. The model also accounts for the competitive binding effects of high estrogen levels on the free T levels in Preg T3. This novel spreadsheet method provides a "user-friendly" approach for estimating the free concentrations of circulating sex hormones and cortisol in men and women.
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Affiliation(s)
- Norman A Mazer
- Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA, United States.
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Mooney MH, Bergwerff AA, van Meeuwen JA, Luppa PB, Elliott CT. Biosensor-based detection of reduced sex hormone-binding globulin binding capacities in response to growth-promoter administrations. Anal Chim Acta 2009; 637:235-40. [DOI: 10.1016/j.aca.2008.08.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 08/19/2008] [Accepted: 08/20/2008] [Indexed: 02/02/2023]
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Mitchell JS, Lowe TE. Ultrasensitive detection of testosterone using conjugate linker technology in a nanoparticle-enhanced surface plasmon resonance biosensor. Biosens Bioelectron 2008; 24:2177-83. [PMID: 19117747 DOI: 10.1016/j.bios.2008.11.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/07/2008] [Accepted: 11/20/2008] [Indexed: 11/16/2022]
Abstract
A rationally designed oligoethylene glycol linker conjugate to testosterone was synthesised and covalently immobilized on a surface plasmon resonance (SPR) biosensor surface. The sensing surface was stable for more than 330 binding and regeneration cycles allowing a high degree of re-use. This surface was then used in the development of an ultrasensitive immunobiosensor system for testosterone in buffer utilizing both secondary antibody and gold nanoparticle signal enhancement. The mechanism for the increased sensitivity results from increased binding mass and a gold plasmon coupling effect. The addition of a secondary antibody with an attached gold nanoparticle increased the signal sensitivity of the assay 12.5-fold compared with primary antibody alone. In the enhanced format the assay had limits of detection (LOD) of 3.7 pgml(-1) with standard in running buffer, and 15.4 pgml(-1) in a stripped human saliva matrix. This immunobiosensor system has sufficient sensitivity to measure testosterone across the broad physiologically relevant range in male saliva (29-290 pgml(-1)) in under 13 min allowing monitoring of testosterone in near real-time.
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Affiliation(s)
- John S Mitchell
- Health and Food Group, The Horticulture and Food Research Institute of New Zealand Ltd., East Street Private Bag 3123, Hamilton, New Zealand
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Excoffon L, Guillaume YC, Woronoff-Lemsi MC, André C. Magnesium effect on testosterone-SHBG association studied by a novel molecular chromatography approach. J Pharm Biomed Anal 2008; 49:175-80. [PMID: 19095394 DOI: 10.1016/j.jpba.2008.10.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 10/20/2008] [Accepted: 10/21/2008] [Indexed: 11/27/2022]
Abstract
A biochromatographic approach is developed to measure for the first time thermodynamic data and magnesium (Mg(2+)) effect for the binding of testosterone (TT) to sex hormone-binding globulin (SHBG) in a wide temperature range. For this, the SHBG was immobilized on a chromatographic support. It was established that this novel SHBG column was stable during an extended period of time. The affinity of TT to SHBG is high and changes slightly with the Mg(2+) concentration because the number of Mg(2+) linked to binding is low. The determination of the testosterone retention with the steroid hormone at different Mg(2+) concentrations and temperatures demonstrated that the Mg(2+) binding heat effect associated with this Mg(2+) release or uptake during this binding was in magnitude around 17kJ/mol corresponding to the model describing the electrostatic attraction that occurs between the negatively charged non specific areas of SHBG and the positively charged of magnesium. At all the magnesium concentrations studied, the DeltaH values were negative due to van der Waals interactions and hydrogen bonding which are engaged at the complex interface confirming strong TT-SHBG hydrogen bond networks. As well, the DeltaS values were all positive due to hydrophobic forces in the testosterone-SHBG complex formation. In addition our results suggest that adaptive conformational transitions contribute to the specific testosterone-SHBG complex formation. As well, in the biological Mg(2+) concentration domain, it was clearly demonstrated that there was an uncompetitive inhibition of Mg(2+) on TT-SHBG binding which led an enhancement of bioavailable TT. Our work indicated that our biochromatographic approach could soon become very attractive for study other SHBG-steroid (or phytoestrogen) binding.
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Affiliation(s)
- L Excoffon
- Equipe des Sciences Séparatives Biologiques et Pharmaceutiques, Université de Franche-Comté, Place Saint Jacques, 25030 Besançon Cedex, France
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15
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Takahashi PY, Votruba P, Abu-Rub M, Mielke K, Veldhuis JD. Age attenuates testosterone secretion driven by amplitude-varying pulses of recombinant human luteinizing hormone during acute gonadotrope inhibition in healthy men. J Clin Endocrinol Metab 2007; 92:3626-32. [PMID: 17579202 DOI: 10.1210/jc.2006-2704] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Whether testosterone (Te) depletion in aging men reflects deficits in the testis, hypothalamus, and/or pituitary gland is unknown. OBJECTIVE Our objective was to quantify the impact of age on gonadal Te secretion driven by amplitude-varying pulses of recombinant human LH (rhLH) in the absence of confounding by endogenous hypothalamo-pituitary signals. DESIGN This was a double-blind, placebo-controlled study. SETTING The setting was an academic medical center. SUBJECTS Fifteen healthy community-dwelling men ages 22-78 yr were included in the study. INTERVENTION Saline or four separate rhLH doses were each infused twice iv in randomized order as one pulse every 2 h over 20 h to stimulate Te secretion, after LH secretion was suppressed by a GnRH-receptor antagonist, ganirelix. MAIN OUTCOME LH and Te concentrations were determined in blood samples collected every 5 min. Maximal and minimal (as well as mean) Te responses were regressed linearly on age to reflect LH peak and nadir (and average) effects, respectively. RESULTS The ganirelix/rhLH paradigm yielded serum LH concentrations of 4.6 +/- 0.22 IU/liter (normal range 1-9). By regression analysis, age was associated with declines in rhLH pulse-stimulated peak and nadir (and mean) concentrations of total Te (P = 0.0068), bioavailable Te (P = 0.0096), and free Te (P = 0.013), as well as lower Te/LH concentration ratios (P < 0.005). Deconvolution analysis suggested that the half-life of infused LH increases by 12%/decade (P = 0.044; R(2) = 0.28). CONCLUSIONS Infusion of amplitude-varying pulses of rhLH during gonadal-axis suppression in healthy men unmasks prominent age-related deficits in stimulated total (39%), bioavailable (66%), and free (63%) Te concentrations, and a smaller age-associated increase in LH half-life. These data suggest that age-associated factors reduce the efficacy of LH pulses.
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Affiliation(s)
- Paul Y Takahashi
- Endocrine Research Unit, Department of Internal Medicine, General Clinical Research Center, Mayo Medical and Graduate Schools of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Luppa PB, Thaler M, Schulte-Frohlinde E, Schreiegg A, Huber U, Metzger J. Unchanged androgen-binding properties of sex hormone-binding globulin in male patients with liver cirrhosis. Clin Chem Lab Med 2006; 44:967-73. [PMID: 16879062 DOI: 10.1515/cclm.2006.186] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Men affected by liver cirrhosis frequently show clinical features of hypogonadism due to hormonal changes, in particular in the metabolism of 17beta-estradiol (E2) and testosterone (T). Sex hormone-binding globulin (SHBG), the major binding protein of these steroids in serum, is regularly elevated in such patients, with its androgen-binding properties possibly altered. In the present study, surface plasmon resonance biosensor techniques were used to determine whether the functional binding properties of this transporter are maintained in this pathology. METHODS We selected 33 male patients with cirrhosis, Child-Pugh grade A or B, and 32 healthy males served as controls. Serum concentrations of T, E2, dehydroepiandrosterone sulfate (DHEAS) and SHBG were measured. In addition, ligand-binding properties of SHBG partially purified from sera of 23 cirrhotic patients and 20 controls were analyzed by a real-time biosensor technique using a surface-coated dihydrotestosterone derivative. RESULTS The sensorgrams revealed that SHBG was fully bioactive in all samples investigated without any changes in binding kinetics. Moreover, total T concentrations were not significantly different in the cirrhotic patient sera (mean+/-SD 18.0+/-8.6 nmol/L) compared to controls (15.6+/-3.7; n.s.), whereas E2 was higher (152+/-60 vs. 96+/-29 pmol/L; p<0.0001) and DHEAS was lower (1493+/-1410 vs. 5099+/-2844 nmol/L; p<0.0001). CONCLUSIONS Owing to elevated SHBG levels without changes in the steroid-binding properties in sera of cirrhotic male patients, free or bioavailable T concentrations are lower. This causes a shift of the hormonal balance in favor of E2, which exhibits a lower affinity for SHBG than androgens and accounts for the endocrine symptoms.
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Affiliation(s)
- Peter B Luppa
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der TU München, Munich, Germany.
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17
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Jin M, Wener MH, Bankson DD. Evaluation of automated sex hormone binding globulin immunoassays. Clin Biochem 2006; 39:91-4. [PMID: 16325792 DOI: 10.1016/j.clinbiochem.2005.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 10/01/2005] [Accepted: 10/07/2005] [Indexed: 11/20/2022]
Abstract
BACKGROUND Sex hormone binding globulin (SHBG) is an important regulator of testosterone and estradiol. STUDY DESIGN We validated the Diagnostic Products Corporation (DPC) and Roche Diagnostic SHBG immunoassays on the DPC Immulite 2000 and Roche Modular E170 analyzers. RESULTS The coefficient of variation for SHBG kits from both manufacturers was in the range of 3.9-7.7% (between-run) and 0.95-5.0% (within-run), free of interference from hemoglobin, bilirubin, lipid, and rheumatoid factor, and linear up to at least 170 nM SHBG. The results of the two methods, however, were biased by up to 29% depending on the SHBG concentration. CONCLUSION The SHBG assays perform well but standardization is needed.
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Affiliation(s)
- Ming Jin
- Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA
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18
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Hammes A, Andreassen TK, Spoelgen R, Raila J, Hubner N, Schulz H, Metzger J, Schweigert FJ, Luppa PB, Nykjaer A, Willnow TE. Role of endocytosis in cellular uptake of sex steroids. Cell 2005; 122:751-62. [PMID: 16143106 DOI: 10.1016/j.cell.2005.06.032] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 05/20/2005] [Accepted: 06/27/2005] [Indexed: 10/25/2022]
Abstract
Androgens and estrogens are transported bound to the sex hormone binding globulin (SHBG). SHBG is believed to keep sex steroids inactive and to control the amount of free hormones that enter cells by passive diffusion. Contrary to the free hormone hypothesis, we demonstrate that megalin, an endocytic receptor in reproductive tissues, acts as a pathway for cellular uptake of biologically active androgens and estrogens bound to SHBG. In line with this function, lack of receptor expression in megalin knockout mice results in impaired descent of the testes into the scrotum in males and blockade of vagina opening in females. Both processes are critically dependent on sex-steroid signaling, and similar defects are seen in animals treated with androgen- or estrogen-receptor antagonists. Thus, our findings uncover the existence of endocytic pathways for protein bound androgens and estrogens and their crucial role in development of the reproductive organs.
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Affiliation(s)
- Annette Hammes
- Max-Delbrueck-Center for Molecular Medicine, 13125 Berlin, Germany
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Abstract
In the year 2003 there was a 17% increase in the number of publications citing work performed using optical biosensor technology compared with the previous year. We collated the 962 total papers for 2003, identified the geographical regions where the work was performed, highlighted the instrument types on which it was carried out, and segregated the papers by biological system. In this overview, we spotlight 13 papers that should be on everyone's 'must read' list for 2003 and provide examples of how to identify and interpret high-quality biosensor data. Although we still find that the literature is replete with poorly performed experiments, over-interpreted results and a general lack of understanding of data analysis, we are optimistic that these shortcomings will be addressed as biosensor technology continues to mature.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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Thaler M, Metzger J, Schreiegg A, Denk B, Gleixner A, Hauptmann H, Luppa PB. Immunoassay for sex hormone-binding globulin in undiluted serum is influenced by high-molecular-mass aggregates. Clin Chem 2004; 51:401-7. [PMID: 15590752 DOI: 10.1373/clinchem.2004.034264] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The new Elecsys chemiluminescence assay for measurement of homodimeric sex hormone-binding globulin (SHBG) was designed for use with undiluted serum, in contrast to other methods that require predilution. During assay development, unexpected calibration difficulties were observed that were attributable to particular biochemical properties of the highly concentrated SHBG in solution. METHODS We used a surface plasmon resonance (SPR) biosensor, which enables biomolecular interaction analysis of SHBG, and size-exclusion chromatography for this investigation. The immunoassay was evaluated for imprecision, linearity, and suitability of the dilution medium, and the method was compared with an IRMA for SHBG. RESULTS The SPR biosensor characterized the special protein properties of SHBG in various concentrations. Above 200 nmol/L there was a strong tendency toward formation of high-molecular-mass aggregates. This was also detectable by size-exclusion chromatography and could be reversed by simple dilution of the sample. On the basis of these results, the dynamic measuring range of the SHBG assay is restricted to 0.350-200 nmol/L. Assay evaluation on a 2010 analyzer revealed excellent precision (CV <or=2.5%). Mean recoveries were 84.2-98.8%. Intermethod comparison with an IRMA yielded a satisfactory concordance of the two assays with a Spearman correlation coefficient of 0.8807. CONCLUSIONS Aggregates of human SHBG may have a detrimental impact on the accurate measurement of the protein if measurements are performed with undiluted serum samples. Further work is needed to clarify whether these high-molecular-mass aggregates influence the free fraction of steroid hormones in vivo.
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Affiliation(s)
- Markus Thaler
- Institute for Clinical Chemistry and Pathobiochemistry, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
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Hauptmann H, Metzger J, Schnitzbauer A, Cuilleron CY, Mappus E, Luppa PB. Syntheses and ligand-binding studies of 1 alpha- and 17 alpha-aminoalkyl dihydrotestosterone derivatives to human sex hormone-binding globulin. Steroids 2003; 68:629-39. [PMID: 12957668 DOI: 10.1016/s0039-128x(03)00092-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on the syntheses of 1 alpha- and 17 alpha-aminoalkyl dihydrotestosterone (DHT) derivatives and the particularly high binding affinity of the 1 alpha-aminohexyl ligand for human sex hormone-binding globulin (SHBG). The two 17 alpha-aminopropyl-17 beta-hydroxy-5 alpha-androstan-3-one (1) and 17 alpha-aminocaproylamidoethyl-17 beta-hydroxy-5 alpha-androstan-3-one (2) derivatives were synthesized via a 17beta-spirooxirane intermediate in high yields. The 1 alpha-aminohexyl-17 beta-hydroxy-5 alpha-androstan-3-one compound (3) was obtained in a seven step synthesis using a copper-catalyzed conjugate addition of a omega-silyloxyhexyl Grignard reagent to 17 beta-benzoyloxy-5 alpha-androst-1-en-3-one. All structures were elucidated based on 1H NMR spectroscopy and mass spectral analyses. The three aminosteroid derivatives were tested as ligands for SHBG by competition experiments with tritiated testosterone as tracer under equilibrium conditions. The association constants of the two 17 alpha-DHT derivatives were approximately 1 x 10(7) M(-1), whereas the 1 alpha-DHT derivative showed a remarkably high binding affinity to SHBG with an association constant of 1.40 x 10(9) M(-1). These aminoalkyl derivatives, substituted either at the D-ring or the A-ring of the steroid skeleton, can be easily coupled onto a carboxymethylated solid state surface of a biosensor. Such a device lends itself to kinetic and thermodynamic studies aimed to provide a better understanding of the biospecific interaction of steroids with SHBG.
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Affiliation(s)
- Hagen Hauptmann
- Institute of Organic Chemistry, Universität Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
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