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Li M, Hasan AA, Chu C, Hocher JG, Liu Y, Zhang X, Chen X, Yard B, Krämer BK, Hocher B. Only bioactive forms of PTH (n-oxPTH and Met18(ox)-PTH) inhibit synthesis of sclerostin - evidence from in vitro and human studies. Pflugers Arch 2024; 476:889-899. [PMID: 38393416 PMCID: PMC11139748 DOI: 10.1007/s00424-024-02928-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/30/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
Sclerostin (SOST) is produced by osteocytes and is known as a negative regulator of bone homeostasis. Parathyroid hormone (PTH) regulates calcium, phosphate as well as vitamin D metabolism, and is a strong inhibitor of SOST synthesis in vitro and in vivo. PTH has two methionine amino acids (positions 8 and 18) which can be oxidized. PTH oxidized at Met18 (Met18(ox)-PTH) continues to be bioactive, whereas PTH oxidized at Met8 (Met8(ox)-PTH) or PTH oxidized at Met8 and Met18 (Met8, Met18(di-ox)-PTH) has minor bioactivity. How non-oxidized PTH (n-oxPTH) and oxidized forms of PTH act on sclerostin synthesis is unknown. The effects of n-oxPTH and oxidized forms of PTH on SOST gene expression were evaluated in UMR106 osteoblast-like cells. Moreover, we analyzed the relationship of SOST with n-oxPTH and all forms of oxPTH in 516 stable kidney transplant recipients using an assay system that can distinguish in clinical samples between n-oxPTH and the sum of all oxidized PTH forms (Met8(ox)-PTH, Met18(ox)-PTH, and Met8, Met18(di-ox)-PTH). We found that both n-oxPTH and Met18(ox)-PTH at doses of 1, 3, 20, and 30 nmol/L significantly inhibit SOST gene expression in vitro, whereas Met8(ox)-PTH and Met8, Met18(di-ox)-PTH only have a weak inhibitory effect on SOST gene expression. In the clinical cohort, multivariate linear regression showed that only n-oxPTH, but not intact PTH (iPTH) nor oxPTH, is independently associated with circulating SOST after adjusting for known confounding factors. In conclusion, only bioactive PTH forms such as n-oxPTH and Met18(ox)-PTH, inhibit SOST synthesis.
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Affiliation(s)
- Mei Li
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Ahmed A Hasan
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Chang Chu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Johann-Georg Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Yvonne Liu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Xiaoli Zhang
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Xin Chen
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Benito Yard
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Bernhard K Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.
- Reproductive, Genetic Hospital of CITIC-Xiangya, Changsha, China.
- Institute of Medical Diagnostics, IMD Berlin-Potsdam, Berlin, Germany.
- Institute of Reproductive and Stem Cell Engineering, NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.
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2
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Zuo J, Hasan AA, Hocher CF, Kalk P, Kleuser B, Krämer BK, Hocher B. Inverse correlation of intact PTH, oxidized PTH as well as non-oxidized PTH with 25-hydroxyvitamin D3 in kidney transplant recipients. Front Endocrinol (Lausanne) 2023; 14:1178166. [PMID: 37324252 PMCID: PMC10264784 DOI: 10.3389/fendo.2023.1178166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023] Open
Abstract
Background 25-hydroxyvitamin D (25(OH)D) and potentially also 1,25-dihydroxyvitamin D (1,25(OH)2D) inhibits the synthesis of parathyroid hormone (PTH) in the chief cells of the parathyroid gland. Clinical studies showing a negative correlation between (25(OH)D and PTH are in good agreement with these findings in basic science studies. However, PTH was measured in these studies with the currently clinically used 2nd or 3rd generation intact PTH (iPTH) assay systems. iPTH assays cannot distinguish between oxidized forms of PTH and non-oxidized PTH. Oxidized forms of PTH are the by far most abundant form of PTH in the circulation of patients with impaired kidney function. Oxidation of PTH causes a loss of function of PTH. Given that the clinical studies done so far were performed with an PTH assay systems that mainly detect oxidized forms of PTH, the real relationship between bioactive non-oxidized PTH and 25(OH)D as well as 1,25(OH)2D is still unknown. Methods To address this topic, we compared for the first time the relationship between 25(OH)D as well as 1,25(OH)2D and iPTH, oxPTH as well as fully bioactive n-oxPTH in 531 stable kidney transplant recipients in the central clinical laboratories of the Charité. Samples were assessed either directly (iPTH) or after oxPTH (n-oxPTH) was removed using a column that used anti-human oxPTH monoclonal antibodies, a monoclonal rat/mouse parathyroid hormone antibody (MAB) was immobilized onto a column with 500 liters of plasma samples. Spearman correlation analysis and Multivariate linear regression were used to evaluate the correlations between the variables. Results There was an inverse correlation between 25(OH)D and all forms of PTH, including oxPTH (iPTH: r=-0.197, p<0.0001; oxPTH: r=-0.203, p<0.0001; n-oxPTH: r=-0.146, p=0.001). No significant correlation was observed between 1,25(OH)2D and all forms of PTH. Multiple linear regression analysis considering age, PTH (iPTH, oxPTH and n-oxPTH), serum calcium, serum phosphor, serum creatinine, fibroblast growth factor 23 (FGF23), osteoprotegerin (OPG), albumin, and sclerostin as confounding factors confirmed these findings. Subgroup analysis showed that our results are not affected by sex and age. Conclusion In our study, all forms of PTH are inversely correlated with 25-hydroxyvitamin D (25(OH)D). This finding would be in line with an inhibition of the synthesis of all forms of PTH (bioactive n-oxPTH and oxidized forms of PTH with minor or no bioactivity) in the chief cells of the parathyroid glad.
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Affiliation(s)
- Jiao Zuo
- Department of Nephrology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Ahmed A. Hasan
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Carl-Friedrich Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
- Klinik für Innere Medizin, Bundeswehrkrankenhaus Berlin, Berlin, Germany
| | - Philipp Kalk
- Department of Nephrology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Diaverum Renal Care Center, Diaverum MVZ Am Neuen Garten Standort Ludwigsfelde, Potsdam, Germany
| | - Burkhard Kleuser
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Bernhard K. Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- European Center for Angioscience ECAS, Medical Faculty Mannheim of the University of Heidelberg, Mannheim, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Reproductive, Genetic Hospital of CITIC-Xiangya, Changsha, China
- Institute of Medical Diagnostics, IMD, Berlin, Germany
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3
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Gaur A, Lipponen J, Yang Y, Armen RS, Wang B. Mutation of Methionine to Asparagine but Not Leucine in Parathyroid Hormone Mimics the Loss of Biological Function upon Oxidation. Biochemistry 2022; 61:981-991. [PMID: 35533300 PMCID: PMC9179810 DOI: 10.1021/acs.biochem.2c00200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/20/2022] [Indexed: 11/29/2022]
Abstract
Human parathyroid hormone (PTH) is an 84-amino acid peptide that contains two methionine (Met) residues located at positions 8 and 18. It has long been recognized that Met residues in PTH are subject to oxidation to become Met sulfoxide, resulting in a decreased biological function of the peptide. However, the mechanism of the lost biological function of PTH oxidation remains elusive. To characterize whether the shift from the hydrophobic nature of the native Met residue to the hydrophilic nature of Met sulfoxide plays a role in the reduction of biological activity upon PTH oxidation, we conducted in silico and in vitro site-directed mutagenesis of Met-8 and Met-18 to the hydrophilic residue asparagine (Asn) or to the hydrophobic residue leucine (Leu) and compared the behavior of these mutated peptides with that of PTH oxidized at Met-8 and/or Met-18. Our results showed that the biological activity of the Asn-8 and Asn-8/Asn-18 mutants was significantly reduced, similar to Met-8 sulfoxide and Met-8/Met-18 sulfoxide analogues, while the functions of Asn-18, Leu-8, Leu-8/Leu-18 mutants, or Met-18 sulfoxide analogues were similar to wild-type PTH. This is rationalized from molecular modeling and immunoprecipitation assay, demonstrating disruption of hydrophobic interactions between Met-8 and Met-18 of PTH and type-1 PTH receptor (PTHR1) upon mutation or oxidation. Thus, these novel findings support the notion that the loss of biological function of PTH upon oxidation of Met-8 is due, at least in part, to the conversion from a hydrophobic to a hydrophilic residue that disrupts direct hydrophobic interaction between PTH and PTHR1.
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Affiliation(s)
- Amit Gaur
- Center
for Translational Medicine, Departments of Medicine and Orthopaedic
Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, United States
| | - Jessica Lipponen
- Center
for Translational Medicine, Departments of Medicine and Orthopaedic
Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, United States
| | - Yanmei Yang
- Center
for Translational Medicine, Departments of Medicine and Orthopaedic
Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, United States
| | - Roger S. Armen
- Department
of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, United States
| | - Bin Wang
- Center
for Translational Medicine, Departments of Medicine and Orthopaedic
Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1020 Locust Street, Philadelphia, Pennsylvania 19107, United States
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4
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Wasserman LA, Yurina LV, Vasilieva AD, Rosenfeld MA. Effect of Hypochlorite- and Hydrogen Peroxide-Induced Oxidation of Fibrinogen on its Thermal Denaturation. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2022. [DOI: 10.1134/s1990793121060105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Korang-Yeboah M, Ketcham S, Shih M, Ako-Adounvo AM, Zhang J, Bandaranayake BM, Abbey-Berko Y, Faustino P, Ashraf M. Effect of formulation and peptide folding on the fibrillar aggregation, gelation, and oxidation of a therapeutic peptide. Int J Pharm 2021; 604:120677. [PMID: 33961953 DOI: 10.1016/j.ijpharm.2021.120677] [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: 02/18/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 11/28/2022]
Abstract
The physical and chemical stability of therapeutic peptides presents challenges in developing robust formulations. The stability of the formulation affects product safety, efficacy and quality. Therefore, an understanding of the effects of formulation variables on the peptide's conformational structure and on its possible physical and chemical degradation is vital. To this end, computational and experimental analysis were employed to investigate the impact of formulation, peptide folding and product handling on oxidation, fibrillar aggregation and gelation of teriparatide. Teriparatide was used as a model drug due to the correlation of its conformation in solution with its pharmacological activity. Fibrillar aggregation and gelation were monitored using four orthogonal techniques. An innovative, automated platform coupled with ion mobility mass spectrometry was used for profiling chemical degradants. Increases in teriparatide concentration, pH, and ionic strength were found to increase the rate of fibrillar aggregation and gelation. Conversely, an increase in peptide folding and stabilization of the folded structures was found to decrease the rate of fibrillar aggregation and gelation. Moreover, the rate of oxidation was found to be inversely related to its solution concentration and extent of peptide folding. The present study provides an insight into formulation strategies designed to reduce the potential risk of physical and chemical degradation of peptides with a defined conformation.
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Affiliation(s)
- Maxwell Korang-Yeboah
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA.
| | - Stephanie Ketcham
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA
| | - Mack Shih
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA
| | - Ann-Marie Ako-Adounvo
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA
| | - Jinhui Zhang
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA.
| | - Bandaranayake M Bandaranayake
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA
| | - Yvonne Abbey-Berko
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA.
| | - Patrick Faustino
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA.
| | - Muhammad Ashraf
- Division of Product Quality Research, Office of Testing and Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, MD, USA
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6
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Delmar JA, Buehler E, Chetty AK, Das A, Quesada GM, Wang J, Chen X. Machine learning prediction of methionine and tryptophan photooxidation susceptibility. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 21:466-477. [PMID: 33898635 PMCID: PMC8060516 DOI: 10.1016/j.omtm.2021.03.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/26/2021] [Indexed: 12/01/2022]
Abstract
Photooxidation of methionine (Met) and tryptophan (Trp) residues is common and includes major degradation pathways that often pose a serious threat to the success of therapeutic proteins. Oxidation impacts all steps of protein production, manufacturing, and shelf life. Prediction of oxidation liability as early as possible in development is important because many more candidate drugs are discovered than can be tested experimentally. Undetected oxidation liabilities necessitate expensive and time-consuming remediation strategies in development and may lead to good drugs reaching patients slowly. Conversely, sites mischaracterized as oxidation liabilities could result in overengineering and lead to good drugs never reaching patients. To our knowledge, no predictive model for photooxidation of Met or Trp is currently available. We applied the random forest machine learning algorithm to in-house liquid chromatography-tandem mass spectrometry (LC-MS/MS) datasets (Met, n = 421; Trp, n = 342) of tryptic therapeutic protein peptides to create computational models for Met and Trp photooxidation. We show that our machine learning models predict Met and Trp photooxidation likelihood with 0.926 and 0.860 area under the curve (AUC), respectively, and Met photooxidation rate with a correlation coefficient (Q2) of 0.511 and root-mean-square error (RMSE) of 10.9%. We further identify important physical, chemical, and formulation parameters that influence photooxidation. Improvement of biopharmaceutical liability predictions will result in better, more stable drugs, increasing development throughput, product quality, and likelihood of clinical success.
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Affiliation(s)
- Jared A Delmar
- Biopharmaceuticals Development, R&D, AstraZeneca, Gaithersburg, MD 20878, USA
| | - Eugen Buehler
- Data Sciences and AI, R&D, AstraZeneca, Gaithersburg, MD 20878, USA
| | - Ashwin K Chetty
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Agastya Das
- Khoury College of Computer Sciences, Northeastern University, Boston, MA 02115, USA
| | | | - Jihong Wang
- Biopharmaceuticals Development, R&D, AstraZeneca, Gaithersburg, MD 20878, USA
| | - Xiaoyu Chen
- Biopharmaceuticals Development, R&D, AstraZeneca, Gaithersburg, MD 20878, USA
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7
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Daley EJ, Khatri A, Dean T, Vilardaga JP, Zaidi SA, Katritch V, Gardella TJ. Ligand-Dependent Effects of Methionine-8 Oxidation in Parathyroid Hormone Peptide Analogues. Endocrinology 2021; 162:6006902. [PMID: 33242090 PMCID: PMC7774776 DOI: 10.1210/endocr/bqaa216] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Indexed: 01/29/2023]
Abstract
LA-PTH is a long-acting parathyroid hormone (PTH) peptide analogue in preclinical development for hypoparathyroidism (HP). Like native PTH, LA-PTH contains a methionine at position 8 (Met8) that is predicted to be critical for function. We assessed the impact of Met oxidation on the functional properties of LA-PTH and control PTH ligands. Oxidation of PTH(1-34) resulted in marked (~20-fold) reductions in binding affinity on the PTH receptor-1 (PTHR1) in cell membranes, similarly diminished potency for 3',5'-cyclic AMP signaling in osteoblastic cell lines (SaOS-2 and UMR106), and impaired efficacy for raising blood calcium in mice. Surprisingly, oxidation of LA-PTH resulted in little or no change in these functional responses. The signaling potency of oxidized-LA-PTH was, however, reduced approximately 40-fold compared to LA-PTH in cells expressing a PTHR1 construct that lacks the N-terminal extracellular domain (ECD). Molecular modeling revealed that while Met8 of both LA-PTH and PTH(1-34) is situated within the orthosteric ligand-binding pocket of the receptor's transmembrane domain bundle (TMD), the Met8 sidechain position is shifted for the 2 ligands so that on Met8 oxidation of PTH(1-34), steric clashes occur that are not seen with oxidized LA-PTH. The findings suggest that LA-PTH and PTH(1-34) engage the receptor differently in the Met8-interaction environment of the TMD bundle, and that this interaction environment can be allosterically influenced by the ECD component of the ligand-receptor complex. The findings should be useful for the future development of novel PTH-based peptide therapeutics for diseases of bone and mineral ion metabolism.
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Affiliation(s)
- Eileen J Daley
- Massachusetts General Hospital and Harvard Medical School, Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Ashok Khatri
- Massachusetts General Hospital and Harvard Medical School, Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Thomas Dean
- Massachusetts General Hospital and Harvard Medical School, Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Jean-Pierre Vilardaga
- University of Pittsburgh School of Medicine, Department of Pharmacology & Chemical Biology, Laboratory for GPCR Biology, Pittsburgh, PA, USA
| | - Saheem A Zaidi
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Vsevolod Katritch
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Thomas J Gardella
- Massachusetts General Hospital and Harvard Medical School, Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
- Correspondence: Thomas J. Gardella, PhD, Endocrine Unit, Massachusetts General Hospital, 50 Blossom St, Thier 10, Boston, MA 02474, USA.
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8
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Zeng S, Querfeld U, Feger M, Haffner D, Hasan AA, Chu C, Slowinski T, Bernd Dschietzig T, Schäfer F, Xiong Y, Zhang B, Rausch S, Horvathova K, Lang F, Karl Krämer B, Föller M, Hocher B. Relationship between GFR, intact PTH, oxidized PTH, non-oxidized PTH as well as FGF23 in patients with CKD. FASEB J 2020; 34:15269-15281. [PMID: 32964520 DOI: 10.1096/fj.202000596r] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/07/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022]
Abstract
Fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH) are regulators of renal phosphate excretion and vitamin D metabolism. In chronic kidney disease (CKD), circulating FGF23 and PTH concentrations progressively increase as renal function declines. Oxidation of PTH at two methionine residues (positions 8 and 18) causes a loss of function. The impact of n-oxPTH and oxPTH on FGF23 synthesis, however, and how n-oxPTH and oxPTH concentrations are affected by CKD, is yet unknown. The effects of oxidized and non-oxidized PTH 1-34 on Fgf23 gene expression were analyzed in UMR106 osteoblast-like cells. Furthermore, we investigated the relationship between n-oxPTH and oxPTH, respectively, with FGF23 in two independent patients' cohorts (620 children with CKD and 600 kidney transplant recipients). While n-oxPTH stimulated Fgf23 mRNA synthesis in vitro, oxidation of PTH in particular at Met8 led to a markedly weaker stimulation of Fgf23. The effect was even stronger when both Met8 and Met18 were oxidized. In both clinical cohorts, n-oxPTH-but not oxPTH-was significantly associated with FGF23 concentrations, independent of known confounding factors. Moreover, with progressive deterioration of kidney function, intact PTH (iPTH) and oxPTH increased substantially, whereas n-oxPTH increased only moderately. In conclusion, n-oxPTH, but not oxPTH, stimulates Fgf23 gene expression. The increase in PTH with decreasing GFR is mainly due to an increase in oxPTH in more advanced stages of CKD.
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Affiliation(s)
- Shufei Zeng
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.,Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Uwe Querfeld
- Division of Gastroenterology, Nephrology and Metabolic Diseases, Department of Pediatrics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Martina Feger
- Department of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Hannover, Germany
| | - Ahmed A Hasan
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.,Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Chang Chu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.,Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Torsten Slowinski
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | - Franz Schäfer
- Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Yingquan Xiong
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.,Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Bingbing Zhang
- Institute of Physiology, University of Tübingen, Tübingen, Germany.,College of Life Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Steffen Rausch
- Department of Physiology, University of Hohenheim, Stuttgart, Germany
| | | | - Florian Lang
- Institute of Nutritional Science, University of Potsdam, Potsdam, Germany
| | - Bernhard Karl Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Michael Föller
- Department of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.,Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, School of Medicine, Hunan Normal University, Changsha, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, China.,Institute of Medical Diagnostics, IMD, Berlin, , Berlin, Germany
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9
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Oxidation of parathyroid hormone. Clin Chim Acta 2020; 506:84-91. [PMID: 32178977 DOI: 10.1016/j.cca.2020.03.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/08/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023]
Abstract
Parathyroid hormone (PTH) is the key hormone regulating calcium homeostasis and, as such, is an important diagnostic and prognostic marker. Although the measurement of PTH has greatly improved over the past few decades, oxidation status thereof is unaccounted for in currently used assays. PTH can be oxidized on methionine residues located at amino acid positions 8 and 18. This is a relevant post-translational modification as, due to refolding of the molecule, it results in the decreased ability to activate the PTH1 receptor. Although this loss of activity after oxidation was observed as early as 1934, only recently a method was developed to measure and distinguish non-oxidized PTH (n-oxPTH) from oxidized PTH. This method creates exciting possibilities for studying more specifically the role of n-oxPTH in physiology and pathology. Therefore, it can now be explored what the clinical implications of measuring n-oxPTH will be. Herein, we review the available evidence of the effect of oxidation on the biological activity of PTH. We also discuss studies examining the mechanism of PTH oxidation in vivo and efforts to stabilize synthetic PTH ex vivo for therapeutic applications. Lastly, the available studies regarding the clinical significance of n-oxPTH are evaluated and future directions discussed.
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10
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Ursem S, Francic V, Keppel M, Schwetz V, Trummer C, Pandis M, Aberer F, Grübler MR, Verheyen ND, März W, Tomaschitz A, Pilz S, Obermayer-Pietsch B, Heijboer AC. The effect of vitamin D supplementation on plasma non-oxidised PTH in a randomised clinical trial. Endocr Connect 2019; 8:518-527. [PMID: 30959477 PMCID: PMC6499917 DOI: 10.1530/ec-19-0097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 04/04/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE PTH can be oxidised in vivo, rendering it biologically inactive. Non-oxidised PTH (n-oxPTH) may therefore give a better image of the hormonal status of the patient. While vitamin D supplementation decreases total PTH (tPTH) concentration, the effect on n-oxPTH concentration is unexplored. We investigated the effect of vitamin D on n-oxPTH concentration in comparison to tPTH and compared the correlations between parameters of calcium, bone and lipid metabolism with n-oxPTH and tPTH. METHODS N-oxPTH was measured in 108 vitamin D-insufficient (25(OH)D <75 nmol/L) hypertensive patients, treated with vitamin D (2800 IE daily) or placebo for 8 weeks in the Styrian Vitamin D Hypertension Trial (NCT02136771). We calculated the treatment effect and performed correlation analyses of n-oxPTH and tPTH with parameters of calcium, bone and lipid metabolism and oxidative stress. RESULTS After treatment, compared to placebo, 25(OH)D concentrations increased, tPTH decreased by 9% (P < 0.001), n-oxPTH by 7% (P = 0.025) and the ratio of n-oxPTH/tPTH increased (P = 0.027). Changes in phosphate and HDL concentration correlated with changes in n-oxPTH, but not tPTH. CONCLUSIONS tPTH and n-oxPTH decrease upon vitamin D supplementation. Our study suggests that vitamin D supplementation reduces the oxidation of PTH, as we observed a small but significant increase in the non-oxidised proportion of PTH upon treatment. In addition, we found that changes in phosphate and HDL concentration showed a relationship with changes in n-oxPTH, but not tPTH. This may be explained by the biological activity of n-oxPTH. Further research should be carried out to establish the clinical relevance of n-oxPTH.
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Affiliation(s)
- Stan Ursem
- Department of Clinical Chemistry, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Endocrine Laboratory, Amsterdam, Netherlands
| | - Vito Francic
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Martin Keppel
- University Institute for Medical and Chemical Laboratory Diagnostics, Paracelsus Medical University, Salzburg, Austria
| | - Verena Schwetz
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Christian Trummer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Marlene Pandis
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Felix Aberer
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Martin R Grübler
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Nicolas D Verheyen
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Winfried März
- Synlab Academy, Synlab Holding Germany GmbH, München, Germany
| | - Andreas Tomaschitz
- Specialist Clinic of Rehabilitation Bad Gleichenberg, Bad Gleichenberg, Austria
| | - Stefan Pilz
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Barbara Obermayer-Pietsch
- Division of Endocrinology and Diabetology, Department of Internal Medicine, Endocrinology Lab Platform, Medical University of Graz, Graz, Austria
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Endocrine Laboratory, Amsterdam, Netherlands
- Department of Clinical Chemistry, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, University of Amsterdam, Endocrine Laboratory, Amsterdam, Netherlands
- Correspondence should be addressed to A C Heijboer:
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11
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Nonaka T, Tsurui N, Mannen T, Kikuchi Y, Shiraki K. Non-chromatographic purification of Teriparatide with a pH-responsive CspB tag. Protein Expr Purif 2018; 155:66-71. [PMID: 30485791 DOI: 10.1016/j.pep.2018.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 11/23/2018] [Accepted: 11/24/2018] [Indexed: 10/27/2022]
Abstract
Cell surface protein B (CspB) from Corynebacterium glutamicum is used as a pH-responsive peptide tag to enable a simple solid-liquid separation method for isolating a CspB fusion protein. Here we demonstrate the first application of a CspB tag for the purification of Teriparatide, which is a biologic drug that is prescribed for osteoporosis. The Teriparatide was constructed as CspB50TEV-Teriparatide, comprising 50 amino acid residues of CspB, the cleavage site of TEV protease, and Teriparatide. CspB50TEV-Teriparatide was expressed in a culture supernatant by C. glutamicum secretion system at 3.0 g/L (equivalent to approximately 1.2 g/L Teriparatide). The CspB50TEV-Teriparatide was precipitated by reducing the pH of the culture supernatant, and the precipitate was then dissolved in a neutral buffer. A TEV protease treatment was applied to cleave the Teriparatide from the CspB50TEV-Teriparatide. Then, the remaining digested CspB50TEV, undigested CspB50TEV-Teriparatide, and TEV protease were precipitated in an acidic pH, whereas the soluble Teriparatide remained in the supernatant. The process had a yield of 96.5% and resulted in Teriparatide with a purity of 98.0% and productivity of 1.1 g/L of C. glutamicum culture. Thus, tag-free Teriparatide was successfully purified from the CspB fusion protein using only pH changes, centrifugation, and protease digestion without the need for chromatography. This versatile purification protocol is expected to be applicable to various proteins from laboratory to industrial scales.
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Affiliation(s)
- Takahiro Nonaka
- Research Institute for Bioscience Product & Fine Chemicals, Ajinomoto Co., Inc, 1-1, Suzuki-Cho, Kawasaki, 210-8681, Japan; Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
| | - Noriko Tsurui
- Research Institute for Bioscience Product & Fine Chemicals, Ajinomoto Co., Inc, 1-1, Suzuki-Cho, Kawasaki, 210-8681, Japan
| | - Teruhisa Mannen
- Research Institute for Bioscience Product & Fine Chemicals, Ajinomoto Co., Inc, 1-1, Suzuki-Cho, Kawasaki, 210-8681, Japan
| | - Yoshimi Kikuchi
- Research Institute for Bioscience Product & Fine Chemicals, Ajinomoto Co., Inc, 1-1, Suzuki-Cho, Kawasaki, 210-8681, Japan
| | - Kentaro Shiraki
- Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
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12
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Kakuta T, Ishida M, Fukagawa M. Critical Governance Issue of Parathyroid Hormone Assays and its Selection in the Management of Chronic Kidney Disease Mineral and Bone Disorders. Ther Apher Dial 2018; 22:220-228. [PMID: 29781225 DOI: 10.1111/1744-9987.12690] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/19/2018] [Accepted: 03/23/2018] [Indexed: 11/28/2022]
Abstract
Measurement of circulating parathyroid hormone (PTH) levels is essential for optimal management of mineral and bone disorders (MBD) in chronic kidney disease (CKD) patients. There are two major types of PTH assays currently in use: intact parathyroid hormone (i-PTH) and whole PTH (w-PTH) assays. The i-PTH assay is the current standard, and considerable information regarding the management of CKD-MBD has been obtained with this method. However, several limitations have been found with the i-PTH assay. One limitation is that i-PTH assay also measures fragments other than full-length PTH (1-84). Another limitation is the existence of multiple readout methods of the i-PTH assay. The w-PTH assay is theoretically ideal because it exclusively detects full-length PTH (1-84). However, clinical data proving the advantages of w-PTH measurement are not sufficient. For uremic patients, Kidney Disease Improving Global Outcomes suggest that PTH levels should be maintained within approximately two to nine times the upper normal limit of the i-PTH assays. The most critical issue in the evaluation of PTH levels is the lack of definitive PTH assay method. Evidence-based recommendations on clinical management goals of PTH are warranted.
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Affiliation(s)
- Takatoshi Kakuta
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University Hachioji Hospital, Tokyo, Japan
| | - Mari Ishida
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University Hachioji Hospital, Tokyo, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University School of Medicine, Isehara, Japan
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13
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Seiler-Mussler S, Limbach AS, Emrich IE, Pickering JW, Roth HJ, Fliser D, Heine GH. Association of Nonoxidized Parathyroid Hormone with Cardiovascular and Kidney Disease Outcomes in Chronic Kidney Disease. Clin J Am Soc Nephrol 2018; 13:569-576. [PMID: 29507005 PMCID: PMC5968904 DOI: 10.2215/cjn.06620617] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 01/02/2018] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES In patients with CKD, elevated plasma parathyroid hormone (PTH) levels are associated with greater cardiovascular morbidity and mortality. However, the reference method for PTH measurement is disputed. It has been argued that measurement of nonoxidized PTH better reflects biologically active PTH than measurements with conventional assays. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS PTH and nonoxidized PTH levels were measured at study baseline in 535 patients with CKD with an eGFR range between 89 and 15 ml/min per 1.73 m2. Patients were followed over 5.1 years for the occurrence of acute heart failure, atherosclerotic events, CKD progression (doubling of serum creatinine or initiation of RRT), or all-cause death. RESULTS Atherosclerotic events, acute heart failure, CKD progression, and deaths from any cause occurred in 116, 58, 73, and 85 patients, respectively. In Kaplan-Meier analyses, patients at the highest PTH and nonoxidized-PTH tertile (79-543 and 12-172 pg/ml, respectively) showed a higher rate of atherosclerotic events, acute heart failure, CKD progression, and death from any cause. After adjustment for eGFR and albuminuria, nonoxidized PTH was no longer associated with atherosclerotic events (hazard ratio third versus first tertile, 1.04 [95% confidence intervals, 0.62-1.75]), acute heart failure (hazard ratio third versus first tertile, 1.24 [95% confidence intervals, 0.59-2.62]), CKD progression (hazard ratio third versus first tertile, 0.93 [95% confidence intervals, 0.46-1.90]), and death from any cause (hazard ratio third versus first tertile, 1.23 [95% confidence intervals, 0.66-2.31]), and PTH lost its association with atherosclerotic events (hazard ratio third versus first tertile, 0.80 [95% confidence intervals, 0.46-1.38]) and CKD progression (hazard ratio third versus first tertile, 0.99 [95% confidence intervals, 0.46-2.10]), although it remained associated with acute heart failure (hazard ratio third versus first tertile, 2.76 [95% confidence intervals, 1.11-6.89]) and all-cause death (hazard ratio third versus first tertile, 2.35 [95% confidence intervals, 1.13-4.89]). After further adjustment for cardiovascular and kidney risk factors, PTH remained associated with all-cause death (hazard ratio third versus first tertile, 2.79 [95% confidence intervals, 1.32-5.89]), but with no other end point. CONCLUSIONS In a cohort of patients with CKD, PTH was associated with all-cause mortality; there was no association of nonoxidized PTH with any of the clinical outcomes examined.
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Affiliation(s)
- Sarah Seiler-Mussler
- Department of Internal Medicine IV–Nephrology and Hypertension, Saarland University Medical Centre, Homburg, Germany
| | - Anne S. Limbach
- Department of Internal Medicine IV–Nephrology and Hypertension, Saarland University Medical Centre, Homburg, Germany
| | - Insa E. Emrich
- Department of Internal Medicine IV–Nephrology and Hypertension, Saarland University Medical Centre, Homburg, Germany
| | - John W. Pickering
- Department of Medicine, University of Otago, Christchurch, New Zealand
- Department of Emergency, Christchurch Hospital, Christchurch, New Zealand; and
| | - Heinz J. Roth
- Medizinisches Versorgungszentrum Dr. Limbach und Kollegen, Heidelberg, Germany
| | - Danilo Fliser
- Department of Internal Medicine IV–Nephrology and Hypertension, Saarland University Medical Centre, Homburg, Germany
| | - Gunnar H. Heine
- Department of Internal Medicine IV–Nephrology and Hypertension, Saarland University Medical Centre, Homburg, Germany
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Ursem SR, Vervloet MG, Hillebrand JJ, de Jongh RT, Heijboer AC. Oxidation of PTH: in vivo feature or effect of preanalytical conditions? ACTA ACUST UNITED AC 2017; 56:249-255. [DOI: 10.1515/cclm-2017-0313] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/11/2017] [Indexed: 11/15/2022]
Abstract
Abstract
Background:
Posttranslational oxidation of parathyroid hormone (PTH) modifies its biological activity. Measurement of non-oxidized PTH (n-oxPTH) could be an improvement in assessing PTH status, as intact PTH may rather reflect oxidative stress. However, it is debated whether oxidation of PTH occurs in vivo, or whether it is mainly an in vitro artifact. The aim of this study was to investigate the influence of different preanalytical conditions on the oxidation of PTH within a wide range of plasma PTH concentrations and oxidation propensity.
Methods:
n-oxPTH was separated from its oxidized form using an affinity column capturing the oxidized PTH. n-oxPTH was measured in eluate using commercially available PTH assays. The study included ethylenediaminetetraacetic acid plasma samples from 17 patients undergoing hemodialysis and 32 healthy subjects. We determined effects of storage temperature, time until centrifugation and freeze-thaw cycles. PTH and n-oxPTH concentrations were measured in each sample using six different immunoassays.
Results:
n-oxPTH concentrations remained unchanged up to 180 min until centrifugation, two freeze-thaw cycles or after storage at −20°C or −80°C up to 79 days. Various methods for n-oxPTH and PTH measurements yielded highly comparable results, apart from standardization differences between various PTH and n-oxPTH assays.
Conclusions:
n-oxPTH concentrations were stable under our study conditions, indicating negligible ex vivo oxidation of PTH. In addition, PTH immunoassays have a different sensitivity for n-oxPTH than for total PTH. For this reason, the n-oxPTH/total PTH ratio cannot be used in absence of a n-oxPTH standard. Clinical implications of determining n-oxPTH require additional study.
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Affiliation(s)
- Stan R. Ursem
- Endocrine Laboratory , Department of Clinical Chemistry , VU University Medical Center , Amsterdam , The Netherlands
| | - Marc G. Vervloet
- Department of Nephrology , VU University Medical Center , Amsterdam , The Netherlands
- Institute for Cardiovascular Research , VU University Medical Center , Amsterdam , The Netherlands
| | - Jacquelien J.G. Hillebrand
- Laboratory of Endocrinology , Department of Clinical Chemistry , Academic Medical Center , Amsterdam , The Netherlands
| | - Renate T. de Jongh
- Endocrine Section, Department of Internal Medicine , VU University Medical Center , Amsterdam , The Netherlands
| | - Annemieke C. Heijboer
- Endocrine Laboratory , Department of Clinical Chemistry , VU University Medical Center , Amsterdam , The Netherlands
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Bahari Javan N, Montazeri H, Rezaie Shirmard L, Jafary Omid N, Barbari GR, Amini M, Ghahremani MH, Rafiee-Tehrani M, Abedin Dorkoosh F. Preparation, characterization and in vivo evaluation of a combination delivery system based on hyaluronic acid/jeffamine hydrogel loaded with PHBV/PLGA blend nanoparticles for prolonged delivery of Teriparatide. Eur J Pharm Sci 2017; 101:167-181. [DOI: 10.1016/j.ejps.2017.02.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/03/2017] [Accepted: 02/09/2017] [Indexed: 01/28/2023]
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16
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Ardura JA, Alonso V, Esbrit P, Friedman PA. Oxidation inhibits PTH receptor signaling and trafficking. Biochem Biophys Res Commun 2016; 482:1019-1024. [PMID: 27908723 DOI: 10.1016/j.bbrc.2016.11.150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 11/27/2016] [Indexed: 02/07/2023]
Abstract
Reactive Oxygen Species (ROS) increase during aging, potentially affecting many tissues including brain, heart, and bone. ROS alter signaling pathways and constitute potential therapeutic targets to limit oxidative damaging effects in aging-associated diseases. Parathyroid hormone receptors (PTHR) are widely expressed and PTH is the only anabolic therapy for osteoporosis. The effects of oxidative stress on PTHR signaling and trafficking have not been elucidated. Here, we used Fluorescence Resonance Energy Transfer (FRET)-based cAMP, ERK, and calcium fluorescent biosensors to analyze the effects of ROS on PTHR signaling and trafficking by live-cell imaging. PTHR internalization and recycling were measured in HEK-293 cells stably transfected with HA-PTHR. PTH increased cAMP production, ERK phosphorylation, and elevated intracellular calcium. Pre-incubation with H2O2 reduced all PTH-dependent signaling pathways. These inhibitory effects were not a result of PTH oxidation since PTH incubated with H2O2 triggered similar responses. PTH promoted internalization and recycling of the PTHR. Both events were significantly reduced by H2O2 pre-incubation. These findings highlight the role of oxidation on PTHR signaling and trafficking, and suggest the relevance of ROS as a putative target in diseases associated with oxidative stress such as age-related osteoporosis.
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Affiliation(s)
- Juan A Ardura
- Instituto de Medicina Molecular Aplicada (IMMA)-Universidad San Pablo CEU, Madrid, Spain; Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, UAM and Red Temática de Investigación Cooperativa de Envejecimiento y Fragilidad (RETICEF)-Instituto de Salud Carlos III, Madrid, Spain; Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Verónica Alonso
- Instituto de Medicina Molecular Aplicada (IMMA)-Universidad San Pablo CEU, Madrid, Spain; Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Pedro Esbrit
- Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, UAM and Red Temática de Investigación Cooperativa de Envejecimiento y Fragilidad (RETICEF)-Instituto de Salud Carlos III, Madrid, Spain
| | - Peter A Friedman
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Torosantucci R, Schöneich C, Jiskoot W. Oxidation of Therapeutic Proteins and Peptides: Structural and Biological Consequences. Pharm Res 2013; 31:541-53. [DOI: 10.1007/s11095-013-1199-9] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 08/25/2013] [Indexed: 10/26/2022]
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18
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Mulinacci F, Poirier E, Capelle MA, Gurny R, Arvinte T. Influence of methionine oxidation on the aggregation of recombinant human growth hormone. Eur J Pharm Biopharm 2013; 85:42-52. [DOI: 10.1016/j.ejpb.2013.03.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 03/14/2013] [Accepted: 03/19/2013] [Indexed: 10/26/2022]
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19
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Audu CO, Cochran JC, Pellegrini M, Mierke DF. Recombinant production of TEV cleaved human parathyroid hormone. J Pept Sci 2013; 19:504-10. [PMID: 23794508 PMCID: PMC3755510 DOI: 10.1002/psc.2528] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/17/2013] [Accepted: 05/22/2013] [Indexed: 11/07/2022]
Abstract
The parathyroid hormone, PTH, is responsible for calcium and phosphate ion homeostasis in the body. The first 34 amino acids of the peptide maintain the biological activity of the hormone and is currently marketed for calcium imbalance disorders. Although several methods for the production of recombinant PTH(1-34) have been reported, most involve the use of cleavage conditions that result in a modified peptide or unfavorable side products. Herein, we detail the recombinant production of (15) N-enriched human parathyroid hormone, (15) N PTH(1-34), generated via a plasmid vector that gives reasonable yield, low-cost protease cleavage (leaving the native N-terminal serine in its amino form), and purification by affinity and size exclusion chromatography. We characterize the product by multidimensional, heteronuclear NMR, circular dichroism, and LC/MS.
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Affiliation(s)
| | - Jared C. Cochran
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405
| | - Maria Pellegrini
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Dale F. Mierke
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
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Li J, Dong S, Townsend SD, Dean T, Gardella TJ, Danishefsky SJ. Chemistry as an Expanding Resource in Protein Science: Fully Synthetic and Fully Active Human Parathyroid Hormone-Related Protein (1-141). Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201207603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Li J, Dong S, Townsend SD, Dean T, Gardella TJ, Danishefsky SJ. Chemistry as an expanding resource in protein science: fully synthetic and fully active human parathyroid hormone-related protein (1-141). Angew Chem Int Ed Engl 2012; 51:12263-7. [PMID: 23124999 DOI: 10.1002/anie.201207603] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Indexed: 01/08/2023]
Affiliation(s)
- Jianfeng Li
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10065, USA
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22
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Hocher B, Armbruster FP, Stoeva S, Reichetzeder C, Grön HJ, Lieker I, Khadzhynov D, Slowinski T, Roth HJ. Measuring parathyroid hormone (PTH) in patients with oxidative stress--do we need a fourth generation parathyroid hormone assay? PLoS One 2012; 7:e40242. [PMID: 22792251 PMCID: PMC3391306 DOI: 10.1371/journal.pone.0040242] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 06/03/2012] [Indexed: 11/24/2022] Open
Abstract
Oxidation of PTH at methionine residues results in loss of biological activity. PTH may be oxidized in patients with renal disease. The aim of this study was to develop an assay considering oxidation of PTH. Oxidized hPTH was analyzed by high resolution nano-liquid chromatography coupled to ESI-FTT tandem mass spectrometry (nanoLC-ESI-FT-MS/MS) directly and after proteolytic cleavage. The oxidized hPTH(1–84) sample shows TIC-peaks at 18–20 min and several mass peaks due to mass shifts caused by oxidations. No significant signal for oxidized hPTH(1–84) species after removal of oxidized PTH molecules by a specific column with monoclonal antibodies (MAB) raised against the oxidized hPTH was detectable. By using this column in samples from 18 patients on dialysis we could demonstrate that measured PTH concentrations were substantially lower when considering oxidized forms of PTH. The relationship between PTH concentrations determined directly and those concentrations measured after removal of the oxidized PTH forms varies substantially. In some patients only 7% of traditionally measured PTH was free of oxidation, whereas in other patients 34% of the traditionally measured PTH was real intact PTH. In conclusion, a huge but not constant proportion of PTH molecules are oxidized in patients requiring dialysis. Since oxidized PTH is biologically inactive, the currently used methods to detect PTH in daily clinical practice may not adequately reflect PTH-related bone and cardiovascular abnormalities in patients on dialysis.
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Affiliation(s)
- Berthold Hocher
- Institute of Nutritional Science, University of Potsdam, Potsdam-Rehbrücke, Germany.
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23
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Alimenti C, Vallesi A, Luporini P, Buonanno F, Ortenzi C. Cell aging-induced methionine oxidation causes an autocrine to paracrine shift of the pheromone activity in the protozoan ciliate, Euplotes raikovi. Exp Cell Res 2012; 318:144-51. [DOI: 10.1016/j.yexcr.2011.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/13/2011] [Accepted: 10/14/2011] [Indexed: 01/10/2023]
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24
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Application of the logic of cysteine-free native chemical ligation to the synthesis of Human Parathyroid Hormone (hPTH). Proc Natl Acad Sci U S A 2011; 108:5986-9. [PMID: 21444787 DOI: 10.1073/pnas.1103118108] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The power of chemical synthesis of large cysteine-free polypeptides has been significantly enhanced through the use of nonproteogenic constructs which bear strategically placed thiol groups, enabling native chemical ligation. Central to these much expanded capabilities is the specific, radical-induced, metal-free dethiolation, which can be accomplished in aqueous medium.
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25
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Demonstrated solid-state stability of parathyroid hormone PTH(1-34) coated on a novel transdermal microprojection delivery system. Pharm Res 2010; 26:2454-63. [PMID: 20183917 DOI: 10.1007/s11095-009-9960-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE This study assessed conditions necessary for at least a 2-year, ambient temperature storage stability of the peptide parathyroid hormone 1-34, or PTH(1-34), coated on a novel transdermal microprojection delivery system, or ZP-PTH. METHODS Liquid coating characterization of high concentration PTH(1-34) formulations (>20% w/w) was assessed by viscosity and contact angle measurements along with RP-HPLC and SEC-HPLC. Solid-state coating morphology of PTH(1-34) on microprojection arrays was determined by SEM, and stability on storage was assessed after dissolution and testing with stability indicating assays. Internal vapor analysis was performed to detect and quantify volatile organics released by patch components into the headspace inside the final package. RESULTS Aggregation and oxidation were the primary degradation mechanisms for solid-state PTH(1-34) in this transdermal delivery system. Although these two degradation pathways can be retarded by appropriate stabilizers and use of foil pouch packaging (nitrogen purged and desiccant), the solid-state drug formulation's compatibility with patch components, particularly the plastic retainer ring, surprisingly dictated PTH(1-34) stability. Internal vapor analysis demonstrated that PTH(1-34) was particularly vulnerable to vapors such as moisture, oxygen, and outgassed formaldehyde, and each of these volatiles played a unique and significant role in PTH(1-34)'s degradation mechanism. CONCLUSIONS Identifying degradation mechanisms of volatile compounds on solid-state PTH(1-34) peptide stability allowed for the rationale for selection of final formulation, system components and packaging conditions. A >2-yr, ambient temperature storage stability was demonstrated for solid-state drug coated on a novel transdermal microprojection delivery system. This system was successfully tested in a Phase 2 clinical trial for the treatment of post-menopausal women with osteoporosis.
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26
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Kamberi M, Kim YJ, Jun B, Riley CM. The effects of sucrose on stability of human brain natriuretic peptide [hBNP (1-32)] and human parathyroid hormone [hPTH (1-34)]. ACTA ACUST UNITED AC 2008; 66:348-56. [PMID: 16316450 DOI: 10.1111/j.1399-3011.2005.00290.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although the effect of sucrose on the physical stability of proteins has been well documented, its impact on their chemical stability is largely unknown. The aim of this study was to investigate the potential effects of sucrose on the structural conformation of human brain natriuretic peptide [hBNP (1-32)] and the synthetic human parathyroid hormone [hPTH (1-34)], and link these effects to chemical degradation pathways of these peptides. The stability of hBNP (1-32) and hPTH (1-34) was studied at pH 5.5. Aggregation was monitored using size exclusion high-performance liquid chromatography (SE-HPLC), whereas oxidation and deamidation products were measured by reversed phase (RP) HPLC. Fourier transform infrared (FT-IR) spectroscopy was used to study the peptides' conformation. Sucrose retarded aggregation, deamidation, and oxidation of hBNP (1-32) and hPTH (1-34), with a maximum effect at relatively high concentrations (as much as 1 m). FT-IR spectroscopy indicated that sucrose maintained the native conformation of hBNP (1-32) and induced small conformation changes in the hPTH (1-34) structure. Sucrose enhanced the stability of hBNP (1-32) and hPTH (1-34) in liquid formulations. The stabilizing effect of sucrose was due to a large extent to retardation of oxidation and deamidation of hBNP (1-32) and hPTH (1-34).
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Affiliation(s)
- M Kamberi
- Department of Analytical Sciences, ALZA Corporation, Mountain View, CA 94039-7210, USA.
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27
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Santarelli LC, Wassef R, Heinemann SH, Hoshi T. Three methionine residues located within the regulator of conductance for K+ (RCK) domains confer oxidative sensitivity to large-conductance Ca2+-activated K+ channels. J Physiol 2006; 571:329-48. [PMID: 16396928 PMCID: PMC1796801 DOI: 10.1113/jphysiol.2005.101089] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Methionine-directed oxidation of the human Slo1 potassium channel (hSlo1) shifts the half-activation voltage by -30 mV and markedly slows channel deactivation at low concentrations of intracellular Ca2+ ([Ca2+]i). We demonstrate here that the contemporaneous mutation of M536, M712 and M739 to leucine renders the channel functionally insensitive to methionine oxidation caused by the oxidant chloramine-T (Ch-T) without altering other functional characteristics. Coexpression with the auxiliary beta1 subunit fails to restore the full oxidative sensitivity to this triple mutant channel. The Ch-T effect is mediated specifically by M536, M712 and M739 because even small changes in this residue combination interfere with the ability to remove the oxidant sensitivity following mutation. Replacement of M712 or M739, but not M536, with the hydrophilic residue glutamate largely mimics oxidation of the channel and essentially removes the Ch-T sensitivity, suggesting that M712 and M739 may be part of a hydrophobic pocket disrupted by oxidation of non-polar methionine to the more hydrophilic methionine sulfoxide. The increase in wild-type hSlo1 open probability caused by methionine oxidation disappears at high [Ca2+]i and biophysical modelling of the Ch-T effect on steady-state activation implicates a decrease in the allosteric coupling between Ca2+ binding and the pore. The dramatic increase in open probability at low [Ca2+]i especially within the physiological voltage range suggests that oxidation of M536, M712 or M739 may enhance the Slo1 BK activity during conditions of oxidative stress, such as those associated with ischaemia-reperfusion and neurodegenerative disease, or in response to metabolic cues.
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Affiliation(s)
- Lindsey Ciali Santarelli
- Department of Physiology, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, PA 19104-6085, USA
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28
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Stadtman ER. Cyclic oxidation and reduction of methionine residues of proteins in antioxidant defense and cellular regulation. Arch Biochem Biophys 2004; 423:2-5. [PMID: 14989257 DOI: 10.1016/j.abb.2003.10.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Earl R Stadtman
- Laboratory of Biochemistry, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012, USA.
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29
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Meyer JD, Ho B, Manning MC. Effects of conformation on the chemical stability of pharmaceutically relevant polypeptides. PHARMACEUTICAL BIOTECHNOLOGY 2002; 13:85-107. [PMID: 11987755 DOI: 10.1007/978-1-4615-0557-0_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Control of chemical instability in protein pharmaceuticals continues to be a critical issue in developing stable formulations. While the effects of pH, buffer composition, ionic strength and temperature remain the most effective methods for controlling hydrolysis and oxidation reactions, it appears that conformational control may also be important. Addition of excipients to maintain native structure and reduce the propensity of the protein to denature and/or aggregate is already a central theme in stabilizing proteins (Arakawa et al., 1993). The same additives have now been found to slow both deamidation and oxidation, whether in solution or in the solid state. What is emerging is an additional approach for producing protein pharmaceuticals that maintain native structure and activity during long-term storage.
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Affiliation(s)
- Jeffrey D Meyer
- Center for Pharmaceutical Biotechnology, Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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30
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Wang ZY, Shimonaga M, Muraoka Y, Kobayashi M, Nozawa T. Methionine oxidation and its effect on the stability of a reconstituted subunit of the light-harvesting complex from Rhodospirillum rubrum. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:3375-82. [PMID: 11422366 DOI: 10.1046/j.1432-1327.2001.02234.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An additional component in the purified core light-harvesting complex (LH1) from wild-type purple photosynthetic bacterium Rhodospirillum rubrum has been identified as an oxidized species of alpha-polypeptide by MALDI-TOF mass spectrometry. This component appears as a slightly earlier-eluting peak in the RP-HPLC chromatogram compared with the authentic alpha-polypeptide. The oxidation site has been determined to be the N-terminal methionine residue by high-resolution NMR spectroscopy, where the methionine is oxidized to methionine sulfoxide in a diastereoisomeric form. Interconversion between the oxidized and authentic alpha-polypeptides has been confirmed by selective oxidation and reduction. The oxidative modification of methionine is shown to have discernible effects on the ability to form B820 subunit with beta-polypeptide and bacteriochlorophyll a, and on the stability of the reconstituted B820 subunit. Both the ability and the stability for the samples using the oxidized alpha-polypeptide are moderately reduced, indicating that the oxidation-induced conformational change in the N-terminal domain of alpha-polypeptide may affect the pigment-binding environment through a long-range interaction. The MALDI-TOF mass results also reveal that the N-terminus of alpha-polypeptide is formylated and no phosphorylation has occurred in this polypeptide.
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Affiliation(s)
- Z Y Wang
- Department of Biomolecular Engineering, Faculty of Engineering, Center for Interdisciplinary Research, Tohoku University, Sendai, Japan.
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31
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Abstract
Methionine (Met) is one of the most readily oxidized amino acid constituents of proteins. It is attacked by H2O2, hydroxyl radicals, hypochlorite, chloramines, and peroxynitrite, all these oxidants being produced in biological systems. The oxidation product, Met sulfoxide, can be reduced back to Met by Met sulfoxide reductase. Numerous proteins lose functional activity by Met oxidation. However, functional activation of proteins by Met oxidation has also been observed. Functional changes by Met oxidation in a given protein appear to have pathophysiological significance in some cases. Considering the reversibility of Met oxidation and the functional changes associated with the oxidation, it seems possible that Met oxidation/reduction in proteins may be one means to control homeostasis in biological systems.
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Affiliation(s)
- W Vogt
- Max Planck Institut für experimentelle Medizin, Göttingen, Germany
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32
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Schermer DT, Bradley MS, Bambino TH, Nissenson RA, Strewler GJ. Functional properties of a synthetic chicken parathyroid hormone-related protein 1-36 fragment. J Bone Miner Res 1994; 9:1041-6. [PMID: 7942150 DOI: 10.1002/jbmr.5650090711] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The biologic activities of human parathyroid hormone-related protein [hPTHrP(1-34] and bovine PTH [bPTH(1-34)] are remarkably similar despite marked sequence divergence in their primary binding domain, residues 25-34. Chicken PTHrP (cPTHrP) is identical to hPTHrP through residue 21. However, in the 25-34 region, cPTHrP displays three fewer basic residues than hPTHrP and contains five residues not present in any other member of the PTH/PTHrP family. To assess the biologic consequences of these structural differences, we compared the activities of synthetic [36Tyr]cPTHrP(1-36)NH2 and hPTHrP(1-34)NH2 with those of bPTH(1-34) in avian systems (chicken renal plasma membranes and 19 day chick embryonic bone cells) and mammalian systems [canine renal plasma membranes and rat osteosarcoma cells (UMR-106-H5)]. In both avian and mammalian systems the binding affinity of [36Tyr]cPTHrP(1-36)NH2 (0.8-3.4 nM) was approximately one-half that of hPTHrP(1-34)NH2 (0.4-1.1 nM). The potencies of [36Tyr]cPTHrP(1-36)NH2 and hPTHrP(1-34)NH2 for activation of adenylate cyclase were similar in canine renal membranes (5.2 and 6.7 nM) and chick bone cells (1.0 nM). In UMR-106 cells and chicken renal membranes the potency of [36Tyr[cPTHrP(1-36)NH2 for activation of adenylate cyclase was about one-half that of [36Tyr]hPTHrP(1-36)NH2. Binding of 125I-[36Tyr]cPTHrP(1-36)NH2 to chick bone cells and chicken renal membranes was completely displaced by bPTH(1-34) and hPTHrP(1-34)NH2: thus there was no evidence for a distinct chicken PTHrP receptor. In general, [36Tyr]cPTHrP(1-36)NH2 and hPTHrP(1-34)NH2 activated adenylate cyclase similarly despite their sequence differences in the 25-32 region.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D T Schermer
- Endocrine Unit, Veterans Administration Medical Center, San Francisco, California
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33
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Wray V, Federau T, Gronwald W, Mayer H, Schomburg D, Tegge W, Wingender E. The structure of human parathyroid hormone from a study of fragments in solution using 1H NMR spectroscopy and its biological implications. Biochemistry 1994; 33:1684-93. [PMID: 8110770 DOI: 10.1021/bi00173a010] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In order to gain insight into the structure of human parathyroid hormone (hPTH), four fragments [hPTH(1-34), hPTH(18-48), hPTH(28-48), and hPTH(53-84)], which cover all regions of the intact hormone, have been investigated by CD and NMR spectroscopy in combination with distance geometry, and restrained molecular dynamics and energy minimization calculations, under a variety of solution conditions. Significantly, all fragments showed little propensity to form stable structures in aqueous solution alone, and it was only on the addition of trifluoroethanol (TFE) that defined structural features were observed. In an extension of earlier work [Klaus et al. (1991) Biochemistry 30, 6936-6942], hPTH(1-34) in 70% trifluoroethanol (TFE) showed two helices that were longer than in 10% TFE, but essentially showed the same characteristics. Although overlap in the 1H NMR spectra prevented the determination of quantitative NOE data for residues 26-30, the combination of the alpha-proton chemical shift data and quantitative NOE data indicated the helices extend from residues 3 to 13 and 15 to 29. No evidence was found for interaction of the two helical regions. The nature and extent of this second helix in the intact hormone were better defined from the data for hPTH(18-48). Under limiting solution conditions, where the fragment assumed its maximum helical content, a well-defined helix was observed between residues 21 and 38 with a possible discontinuity between Leu-28 and Gln-29. There was little evidence of any form of secondary structure between Gly-38 and the terminus of this fragment, Ser-48. In keeping with this result, the shorter fragment, hPTH(28-48), showed little evidence of stable secondary structure on addition of TFE. From the alpha-proton chemical shifts residues 23-27 appeared to sustain helical structure more readily than the rest of molecule under all solution regimes in both hPTH(1-34) and hPTH(18-48). In contrast to the other two longer fragments hPTH(53-84) showed little propensity for helical secondary structure even at the highest TFE concentrations. However, there was evidence that the molecule did adopt a defined three-dimensional structure. Various long-range NOE's were observed in 10% TFE that allowed the calculation of an open tertiary structure consisting of an initial series of turns surrounded by a loop structure of several loose turns.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- V Wray
- Abteilung für Molekulare Strukturforschung, GBF-Gesellschaft für Biotechnologische Forschung, Braunschweig, FRG
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34
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Willis KJ. Interaction with model membrane systems induces secondary structure in amino-terminal fragments of parathyroid hormone related protein. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1994; 43:23-8. [PMID: 8138348 DOI: 10.1111/j.1399-3011.1994.tb00371.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The secondary structure of amino terminal fragments of human parathyroid hormone related protein (PTHrP) in aqueous solution, in trifluoroethanol solution and in the presence of model membrane systems has been studied by circular dichroism (CD) spectroscopy. Far-UV CD spectra of PTHrP 1-40, 1-34 amide, 7-34 amide and 1-16 are consistent with a predominantly unordered structure. Addition of trifluoroethanol stabilized alpha-helical structure in the 1-34 amide and 7-34 amide peptides. The effect reached a plateau at a trifluoroethanol concentration of approximately 40%, and a helix content of some 23 residues was determined. PTHrP 1-34 amide interacted with palmitoyloleoylphosphatidyl serine vesicles and exhibited an increased alpha-helix content of approximately 12 helical residues. Similar results were observed for monomyristoyllecithin micelles and sodium dodecyl sulfate micelles. No interaction with dimyristoylphosphatidylcholine vesicles was detected by CD. The ability to bind to palmitoyloleoylphosphotidyl serine vesicles was also a feature of the 1-40 and 7-34 fragments, while the 1-16 fragment was apparently unaffected by interaction with this model membrane system. These results indicate that the conformational properties of the functionally significant amino terminal 1-34 region of PTHrP parallel those reported for the corresponding, but largely nonhomologous, region of parathyroid hormone. Conformational similarities may account for the ability of PTHrP to mimic the functional properties of parathyroid hormone.
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Affiliation(s)
- K J Willis
- Allelix Biopharmaceuticals Inc., Mississauga, Ontario, Canada
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35
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Abstract
We propose fuzzy clustering as a method to analyze molecular dynamics (MD) trajectories, especially of proteins and polypeptides. A fuzzy cluster analysis locates classes of similar three-dimensional conformations explored during a molecular dynamics simulation. The method can be readily applied to results from both equilibrium and nonequilibrium simulations, with clustering on either global or local structural parameters. The potential of this technique is illustrated by results from fuzzy cluster analyses of trajectories from MD simulations of various fragments of human parathyroid hormone (PTH). For large molecules, it is more efficient to analyze the clustering of root-mean-square distances between conformations comprising the trajectory. We found that the results of the clustering analysis were unambiguous, in terms of the optimal number of clusters of conformations, for the majority of the trajectories examined. The conformation closest to the cluster center can be chosen as being representative of the class of structures making up the cluster, and can be further analyzed, for example, in terms of its secondary structure. The CPU time used by the cluster analysis was negligible compared to the MD simulation time.
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Affiliation(s)
- H L Gordon
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario
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36
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Neugebauer W, Surewicz WK, Gordon HL, Somorjai RL, Sung W, Willick GE. Structural elements of human parathyroid hormone and their possible relation to biological activities. Biochemistry 1992; 31:2056-63. [PMID: 1311201 DOI: 10.1021/bi00122a023] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human parathyroid hormone (hPTH) and several deletion analogues were examined for the presence of secondary structure using circular dichroism spectroscopy. The spectra of hPTH and the deletion analogues 8-84, 34-53, 53-84, 1-34, 13-34, 1-19, and 20-34, in neutral, aqueous buffer, gave no evidence for extensive secondary structure. An alpha-helical-like spectral contribution was found to arise from a region within peptide 13-34. This spectral contribution was speculated to arise from partial stability of a helix consisting of residues 17-29. Molecular dynamics simulations of peptide 1-34 suggested that this peptide tends to fold with a bend defined by residues 10-14, with the amino-terminal and carboxyl-terminal residues tending to be in more extended forms and the other residues in helical-like conformations. The addition of trifluoroethanol promoted the formation of alpha-helix, mainly in the 1-34 region. The putative helix comprised of residues 17-29 was stabilized by the addition of 10-20% TFE, while a second putative helix proximal to the amino terminus, and comprised of residues 3-11, was stabilized by slightly higher concentrations of TFE. An amphiphilic sequence was identified within the 20-34 fragment. The development of alpha-helix on binding this fragment, and other analogues containing this sequence, to palmitoyloleoylphosphatidylserine vesicles provided experimental evidence for the potential role of this amphiphilic sequence in binding to membranes or to a membrane receptor. The relationships between these alpha-helical regions in 1-34, either potentiated by trifluoroethanol or lipid vesicles, are discussed in terms of different receptor-binding regions within hPTH.
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Affiliation(s)
- W Neugebauer
- Protein Structure and Function Section, National Research Council of Canada, Ottawa
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37
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Gardella T, Axelrod D, Rubin D, Keutmann H, Potts J, Kronenberg H, Nussbaum S. Mutational analysis of the receptor-activating region of human parathyroid hormone. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98816-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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38
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Logue FC, Perry B, Biggart EM, Chapman RS, Beastall GH. Production and characterisation of monoclonal antibodies to parathyroid hormone (1-34). J Immunol Methods 1991; 137:159-66. [PMID: 2013695 DOI: 10.1016/0022-1759(91)90020-g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Monoclonal antibodies to the biologically active N terminal region of parathyroid hormone (PTH) suitable for use in the measurement of circulating PTH concentrations have proved difficult to produce. In this study, no serum PTH antibody titres could be detected in mice using synthetic human PTH (1-34) (free or coupled to albumin) or PTH (1-10) (coupled to keyhole limpet haemocyanin) as immunogen. A consistent response to PTH (1-34) peptide was obtained in DA rats. We have produced five monoclonal antibodies to PTH (1-34) derived from the fusion of DA rat spleen cells and the mouse myeloma line X63 Ag.8.653. Bulk production of the antibodies was achieved using congenitally athymic mice for ascites production. Antibody assessment studies revealed the antibodies to be sensitive to the oxidation state of the methionine residues in PTH (1-34). Two of the antibodies, 3B3 and 6E3, were shown to be of potential use in measuring circulating PTH (1-84) when used in combination with available antibodies to C terminal PTH. A third antibody, 4G3, which failed to recognise PTH (1-84) when used in combination with 3B3, formed the basis of a specific assay for PTH (1-34).
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Affiliation(s)
- F C Logue
- Institute of Biochemistry, Royal Infirmary, Glasgow, U.K
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39
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Analogues of parathyroid hormone modified at positions 3 and 6. Effects on receptor binding and activation of adenylyl cyclase in kidney and bone. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52390-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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40
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Laethem R, Zull JE. Characterization of the interaction of parathyroid hormone with the mitochondrial ATPase. Arch Biochem Biophys 1990; 282:161-9. [PMID: 2145804 DOI: 10.1016/0003-9861(90)90100-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Parathyroid hormone (PTH) has been shown to bind specifically to the beta subunit of the mitochondrial ATPase on nitrocellulose blots. We have now examined this interaction further, using intact mitochondria, submitochondrial particles, and the purified F1 ATPase. With intact mitochondria, 1 microM concentrations of PTH and its biologically active 1-34 fragment activate the ATPase about 3-fold. This effect was reduced to a 1.4-fold activation with 3-34 and 7-34 fragments of the hormone, and oxidized PTH gave no detectable activity. Activation could only be observed below pH 7. PTH had no significant effect on the activity of the purified enzyme or on submitochondrial particles. However, specific binding of an iodinated PTH analog, [Nle 8,18-Tyr 34] bPTH (1-34) amide, was found with submitochondrial particles and the purified ATPase. Binding affinity with the purified enzyme was about 10(-3) that of the plasma membrane receptor, and the molar stoichiometry was close to 1:1 (PTH:intact enzyme). With submitochondrial particles the affinity was about 10-fold higher than with the purified enzyme. This binding was further examined with PTH derivatives and fragments, and compared to that seen in the plasma membrane receptor. Oxidation of methionine 18 in PTH reduced the affinity about 50%, oxidation of methionine 8 reduced the affinity 95%, and oxidation of both methionines further decreased affinity in both membranes and submitochondrial particles. However, when compared to the native hormone, the 3-34 and 7-34 PTH fragments had much higher affinity for the submitochondrial particles than for the plasma membranes. PTH also reduced chemical crosslinking of the ATP analog, p-fluorosulfonyl benzoyl 5'-adenosine, to the alpha subunit of this enzyme, but did not alter labeling of the enzyme with 3'-O-(4'-benzoyl) benzoyl ATP, suggesting that the hormone binds near a regulatory nucleotide binding site. Direct chemical crosslinking of PTH to the beta-subunit of the enzyme was attained with a cleavable, photoactivate crosslinker, sulfosuccinimidyl 2-(p-azidosalicylamido) ethyl-1,3-dithiopropionate. The crosslinked protein was cleaved with cyanogen bromide and the labeled fragments were sequenced. The labeled fragments were found to be segments of the protein which have previously been implicated as being close to the noncatalytic ATP binding sites.
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Affiliation(s)
- R Laethem
- Department of Biology, Case Western Reserve University, Cleveland, Ohio 44106
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