1
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Abdesselem M, Pétri N, Kuhner R, Mousseau F, Rouffiac V, Gacoin T, Laplace-Builhé C, Alexandrou A, Bouzigues CI. Real-time in vivo ROS monitoring with luminescent nanoparticles reveals skin inflammation dynamics. BIOMEDICAL OPTICS EXPRESS 2023; 14:5392-5404. [PMID: 37854553 PMCID: PMC10581786 DOI: 10.1364/boe.501914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 10/20/2023]
Abstract
Reactive oxygen species (ROS) are key regulators in numerous pathological contexts, including cancer or inflammation. Their role is complex, which justifies the need for methods enabling their quantitative and time-resolved monitoring in vivo, in the perspective to profile tissues of individual patients. However, current ROS detection methods do not provide these features. Here, we propose a new method based on the imaging of lanthanide-ion nanoparticles (GdVO4:Eu), whose photoluminescence is modulated by the surrounding ROS concentration. We monitored their luminescence after intradermic injection in a mouse ear submitted to an inflammation-inducing topical stimulus. Based on this approach, we quantified the ROS concentration after inflammation induction and identified a two-step kinetics of ROS production, which may be attributed to the response of resident immune cells and their further recruitment at the inflammation locus.
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Affiliation(s)
- M Abdesselem
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
| | - N Pétri
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
| | - R Kuhner
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
| | - F Mousseau
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
| | - V Rouffiac
- Photon Imaging and Flow Cytometry, CNRS, INSERM, Gustave Roussy Cancer Campus, 114, rue Edouard Vaillant, 94805 Villejuif Cedex, France
| | - T Gacoin
- Laboratoire de Physique de la Matière Condensée, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, 91128 Palaiseau cedex, France
| | - C Laplace-Builhé
- Photon Imaging and Flow Cytometry, CNRS, INSERM, Gustave Roussy Cancer Campus, 114, rue Edouard Vaillant, 94805 Villejuif Cedex, France
| | - A Alexandrou
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
| | - C I Bouzigues
- Laboratory for Optics and Biosciences, Ecole polytechnique, Institut Polytechnique de Paris, CNRS, INSERM, 91128 Palaiseau cedex, France
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2
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Solo P, Arockia doss M, Prasanna D. Designing and docking studies of imidazole-based drugs as potential inhibitors of myeloperoxidase (MPO) mediated inflammation and oxidative stress. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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3
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Camp OG, Bai D, Awonuga A, Goud P, Abu-Soud HM. Hypochlorous acid facilitates inducible nitric oxide synthase subunit dissociation: The link between heme destruction, disturbance of the zinc-tetrathiolate center, and the prevention by melatonin. Nitric Oxide 2022; 124:32-38. [PMID: 35513289 DOI: 10.1016/j.niox.2022.04.006] [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: 02/28/2022] [Revised: 04/20/2022] [Accepted: 04/29/2022] [Indexed: 11/25/2022]
Abstract
Inducible nitric oxide synthase (iNOS) is a zinc-containing hemoprotein composed of two identical subunits, each containing a reductase and an oxygenase domain. The reductase domain contains binding sites for NADPH, FAD, FMN, and tightly bound calmodulin and the oxygenase domain contains binding sites for heme, tetrahydrobiopterin (H4B), and l-arginine. The enzyme converts l-arginine into nitric oxide (NO) and citrulline in the presence of O2. It has previously been demonstrated that myeloperoxidase (MPO), which catalyzes formation of hypochlorous acid (HOCl) from hydrogen peroxide (H2O2) and chloride (Cl-), is enhanced in inflammatory diseases and could be a potent scavenger of NO. Using absorbance spectroscopy and gel filtration chromatography, we investigated the role of increasing concentrations of HOCl in mediating iNOS heme destruction and subsequent subunit dissociation and unfolding. The results showed that dimer iNOS dissociation between 15 and 100 μM HOCl was accompanied by loss of heme content and NO synthesis activity. The dissociated subunits-maintained cytochrome c and ferricyanide reductase activities. There was partial unfolding of the subunits at 300 μM HOCl and above, and the subunit unfolding transition was accompanied by loss of reductase activities. These events can be prevented when the enzyme is preincubated with melatonin prior to HOCl addition. Melatonin supplementation to patients experiencing low NO levels due to inflammatory diseases may be helpful to restore physiological NO functions.
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Affiliation(s)
- Olivia G Camp
- Departments of Obstetrics and Gynecology and Biochemistry and Molecular Biology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, 48201, USA; Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - David Bai
- Departments of Obstetrics and Gynecology and Biochemistry and Molecular Biology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Awoniyi Awonuga
- Departments of Obstetrics and Gynecology and Biochemistry and Molecular Biology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Pravin Goud
- Division of Reproductive Endocrinology and Infertility & California IVF Fertility Center, Department of Obstetrics and Gynecology, University of California Davis, Sacramento, CA, 95833, USA; California Northstate University Medical College, Elk Grove, CA, 95757, USA
| | - Husam M Abu-Soud
- Departments of Obstetrics and Gynecology and Biochemistry and Molecular Biology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, 48201, USA; Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA; Department of Microbiology, Immunology and Biochemistry, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
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4
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Inducible Animal Models of Skin Fibrosis; Updated Review of the Literature. JORJANI BIOMEDICINE JOURNAL 2022. [DOI: 10.52547/jorjanibiomedj.10.2.69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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5
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Xu Z, Wang X, Duan T, He R, Wang F, Zhou X. Development of an ultrafast fluorescent probe for specific recognition of hypochlorous acid and its application in live cells. RSC Adv 2021; 11:24669-24672. [PMID: 35481002 PMCID: PMC9036915 DOI: 10.1039/d1ra04082k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/02/2021] [Indexed: 12/17/2022] Open
Abstract
Hypochlorous acid (HOCl), a highly potent oxidant of reactive oxygen species, plays critical roles in many physiological and pathological processes. In this work, a novel coumarin-based fluorescent probe, Cou–HOCl, was prepared for the detection of HOCl. The probe exhibited good selectivity over other analytes, excellent sensitivity with a detection limit of 16 nM, and fast response within 5 s. And further study demonstrated that the probe could be used not only to image exogenous HOCl in various cells, but also to determine the fluctuating levels of HOCl in macrophage cells during inflammation. Hypochlorous acid (HOCl), a highly potent oxidant of reactive oxygen species, plays critical roles in many physiological and pathological processes. In this work, we designed a simple coumarin-based fluorescent probe, Cou–HOCl, for detecting HOCl in inflammatory cells.![]()
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Affiliation(s)
- Zhencai Xu
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China .,Guanyun People's Hospital Lianyungang 222000 China
| | - Xiaofeng Wang
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China
| | - Tingting Duan
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China
| | - Rong He
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China
| | - Fangwu Wang
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China
| | - Xuejun Zhou
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Hainan Medical University Haikou 570102 China
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6
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Herold-Majumdar OM, Lopez Pita S, Dominguez Estevez F, Wawrzynczyk J, Loureiro PEG, Felby C. Removal of hard COD from acidic eucalyptus kraft pulp bleach plant effluent streams using oxidoreductases. Biotechnol Appl Biochem 2021; 69:687-700. [PMID: 33751654 DOI: 10.1002/bab.2144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/09/2021] [Indexed: 11/06/2022]
Abstract
The bleach plant of a pulp and paper (P&P) mill presents a major source of wastewater containing toxic organic matter characterized as chemical oxygen demand (COD). Due to their high oxidizing power, oxidoreductases hold promise to be a key solution for the removal of dissolved organic material. Here, four oxidoreductases from different enzyme families were selected to treat bleach plant effluents. Haloperoxidase treatment of the final effluent resulted in the highest levels of decolorization (71%) and reduction of aromatic compounds (36%). Using single compound analysis, 27 low molecular weight compounds were found to be persistent throughout the wastewater treatment process and, therefore, classified as hard COD. The tested enzymes efficiently removed several of the identified COD compounds. Hence, this study suggests that the application of oxidoreductases will serve as an environmental-friendly solution for reducing waste from P&P production.
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Affiliation(s)
- Owik Matthias Herold-Majumdar
- Novozymes A/S, Bagsvaerd, Denmark.,Section for Forest, Nature and Biomass, University of Copenhagen Faculty of Science, Copenhagen, Denmark
| | - Sabela Lopez Pita
- Novozymes A/S, Bagsvaerd, Denmark.,Section for Forest, Nature and Biomass, University of Copenhagen Faculty of Science, Copenhagen, Denmark
| | | | | | | | - Claus Felby
- Novo Nordisk Fonden, Hellerup, Copenhagen, Denmark
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7
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Jeelani R, Chatzicharalampous C, Kohan-Ghadr HR, Bai D, Morris RT, Sliskovic I, Awonuga A, Abu-Soud HM. Hypochlorous acid reversibly inhibits caspase-3: a potential regulator of apoptosis. Free Radic Res 2020; 54:43-56. [DOI: 10.1080/10715762.2019.1694675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Roohi Jeelani
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
| | - Charalampos Chatzicharalampous
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
| | - Hamid-Reza Kohan-Ghadr
- Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State University College of Human Medicine, Grand Rapids, MI, USA
| | - David Bai
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robert T. Morris
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
- Karmanos Cancer Institute, Detroit, MI, USA
| | - Inga Sliskovic
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
| | - Awoniyi Awonuga
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, the CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Microbiology, Immunology and Biochemistry and Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
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8
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Jayaraj P, Narasimhulu CA, Maiseyeu A, Durairaj R, Rao S, Rajagopalan S, Parthasarathy S, Desikan R. Methoxyphenol derivatives as reversible inhibitors of myeloperoxidase as potential antiatherosclerotic agents. Future Med Chem 2020; 12:95-110. [PMID: 31769316 PMCID: PMC7333589 DOI: 10.4155/fmc-2019-0080] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/23/2019] [Indexed: 01/26/2023] Open
Abstract
Aim: To evaluate new chemical entities, based on ferulic acid scaffolds, as reversible myeloperoxidase inhibitors (MPOI). Methodology & results:In silico docking studies are performed with MPO protein as a target for several ferulic acid analogs followed by multiple in vitro assays to validate this approach. Two lead compounds 2a and 3 are identified with optimum docking and IC50 values: -7.95 kcal/mol, 0.9 μM and -8.35 kcal/mol, 8.5 μM, respectively. These MPOIs are able to inhibit oxidation of high-density lipoprotein and further promoted functionality of high-density lipoprotein. Conclusion: Lead analogs are potent MPOIs that exert specific effects on MPO-mediated oxidation as well as inflammatory pathways. It also acts as promoters of cholesterol efflux that sheds light on pharmacological approach in atherosclerosis treatment.
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Affiliation(s)
- Premkumar Jayaraj
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore 632014, India
| | - Chandrakala A Narasimhulu
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Andrei Maiseyeu
- Cardiovascular Research Institute, Case Western Reserve University, School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - Rekha Durairaj
- Cardiovascular Research Institute, Case Western Reserve University, School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - Shashidhar Rao
- Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, NJ 08554, USA
| | - Sanjay Rajagopalan
- Cardiovascular Research Institute, Case Western Reserve University, School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - Sampath Parthasarathy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
| | - Rajagopal Desikan
- Carmel Biosciences, 3562 Habersham at Northlake, Building J, Suite A, Tucker, GA 30084, USA
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore 632014, India
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9
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Jun YW, Hebenbrock M, Kool ET. A fluorescent hydrazone exchange probe of pyridoxal phosphate for the assessment of vitamin B6 status. Chem Commun (Camb) 2019; 56:317-320. [PMID: 31808778 PMCID: PMC7061904 DOI: 10.1039/c9cc08458d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abnormal vitamin B6 status, marked by deficient intracellular concentrations of pyridoxal phosphate (PLP), is classified as a direct biomarker based on its biomedical significance. However, there exist no direct methods for measuring vitamin B6 status in intact cells. Here we describe the development of a fluorogenic probe, RAB6, which shows remarkable selectivity for PLP among the B6 vitamers and other cellular aldehydes.
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Affiliation(s)
- Yong Woong Jun
- Department of Chemistry and ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.
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10
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Li T, Wang L, Lin S, Xu X, Liu M, Shen S, Yan Z, Mo R. Rational Design and Bioimaging Applications of Highly Specific “Turn-On” Fluorescent Probe for Hypochlorite. Bioconjug Chem 2018; 29:2838-2845. [DOI: 10.1021/acs.bioconjchem.8b00430] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Teng Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Leikun Wang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Shiqi Lin
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Xiao Xu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Meng Liu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Shiyang Shen
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Zhengyu Yan
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
| | - Ran Mo
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China
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11
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Jeelani R, Maitra D, Chatzicharalampous C, Najeemuddin S, Morris RT, Abu-Soud HM. Melatonin prevents hypochlorous acid-mediated cyanocobalamin destruction and cyanogen chloride generation. J Pineal Res 2018; 64:10.1111/jpi.12463. [PMID: 29247550 PMCID: PMC5843513 DOI: 10.1111/jpi.12463] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 12/05/2017] [Indexed: 12/15/2022]
Abstract
Hypochlorous acid (HOCl) is a potent cytotoxic oxidant generated by the enzyme myeloperoxidase (MPO) in the presence of hydrogen peroxide (H2 O2 ) and chloride (Cl- ). Elevated levels of HOCl play an important role in various pathological conditions through oxidative modification of several biomolecules. Recently, we have highlighted the ability of HOCl to mediate the destruction of the metal-ion derivatives of tetrapyrrole macrocyclic rings such as hemoproteins and vitamin B12 (VB12 ) derivatives. Destruction of cyanocobalamin, a common pharmacological form of VB12 mediated by HOCl, results in the generation of toxic molecular products such as chlorinated derivatives, corrin ring cleavage products, the toxic blood agents cyanide (CN- ) and cyanogen chloride (CNCl), and redox-active free cobalt. Here, we show that melatonin prevents HOCl-mediated cyanocobalamin destruction, using a combination of UV-Vis spectrophotometry, high-performance liquid chromatography analysis, and colorimetric CNCl assay. Identification of several melatonin oxidation products suggests that the protective role of melatonin against HOCl-mediated cyanocobalamin destruction and subsequent CNCl generation is at the expense of melatonin oxidation. Collectively, this work highlights that, in addition to acting as an antioxidant and as a MPO inhibitor, melatonin can also prevent VB12 deficiency in inflammatory conditions such as cardiovascular and neurodegenerative diseases, among many others.
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Affiliation(s)
- Roohi Jeelani
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, C. S. Mott Center for Human Growth and Development, 275 E. Hancock, Detroit, MI, 48201 USA
| | - Dhiman Maitra
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, C. S. Mott Center for Human Growth and Development, 275 E. Hancock, Detroit, MI, 48201 USA
| | - Charalampos Chatzicharalampous
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, C. S. Mott Center for Human Growth and Development, 275 E. Hancock, Detroit, MI, 48201 USA
| | - Syed Najeemuddin
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, C. S. Mott Center for Human Growth and Development, 275 E. Hancock, Detroit, MI, 48201 USA
| | - Robert T. Morris
- Division of Gynecologic Oncology, Department of Oncology, Wayne State University and Karmanos Cancer Institute, Detroit, MI, 48201 USA
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, Wayne State University School of Medicine, C. S. Mott Center for Human Growth and Development, 275 E. Hancock, Detroit, MI, 48201 USA
- Department of Microbiology, Immunology and Biochemistry, Wayne State University School of Medicine, Detroit, MI, 48201 USA
- Address correspondence to: Husam Abu-Soud, Department of Obstetrics and Gynecology, C. S. Mott Center for Growth and Development, Wayne State University, 275 E. Hancock Detroit, MI 48201. Tel: 313/577-6178; Fax: 313/577-8554;
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12
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Verrastro I, Tveen-Jensen K, Spickett CM, Pitt AR. The effect of HOCl-induced modifications on phosphatase and tensin homologue (PTEN) structure and function. Free Radic Res 2018; 52:232-247. [DOI: 10.1080/10715762.2018.1424333] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Ivan Verrastro
- School of Life and Health Sciences, Aston University, Birmingham, UK
| | | | | | - Andrew R. Pitt
- School of Life and Health Sciences, Aston University, Birmingham, UK
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13
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Skin fibrosis: Models and mechanisms. Curr Res Transl Med 2016; 64:185-193. [PMID: 27939457 DOI: 10.1016/j.retram.2016.06.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/15/2016] [Accepted: 06/17/2016] [Indexed: 02/06/2023]
Abstract
Matrix synthesis, deposition and remodeling are complex biological processes that are critical in development, maintenance of tissue homeostasis and repair of injured tissues. Disturbances in the regulation of these processes can result in severe pathological conditions which are associated with tissue fibrosis as e.g. in Scleroderma, cutaneous Graft-versus-Host-Disease, excessive scarring after trauma or carcinogenesis. Therefore, finding efficient treatments to limit skin fibrosis is of major clinical importance. However the pathogenesis underlying the development of tissue fibrosis is still not entirely resolved. In recent years progress has been made unraveling the complex cellular and molecular mechanisms that determine fibrosis. Here we provide an overview of established and more recently developed mouse models that can be used to investigate the mechanisms of skin fibrosis and to test potential therapeutic approaches.
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14
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Chandler JD, Min E, Huang J, McElroy CS, Dickerhof N, Mocatta T, Fletcher AA, Evans CM, Liang L, Patel M, Kettle AJ, Nichols DP, Day BJ. Antiinflammatory and Antimicrobial Effects of Thiocyanate in a Cystic Fibrosis Mouse Model. Am J Respir Cell Mol Biol 2015; 53:193-205. [PMID: 25490247 DOI: 10.1165/rcmb.2014-0208oc] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Thiocyanate (SCN) is used by the innate immune system, but less is known about its impact on inflammation and oxidative stress. Granulocytes oxidize SCN to evolve the bactericidal hypothiocyanous acid, which we previously demonstrated is metabolized by mammalian, but not bacterial, thioredoxin reductase (TrxR). There is also evidence that SCN is dysregulated in cystic fibrosis (CF), a disease marked by chronic infection and airway inflammation. To investigate antiinflammatory effects of SCN, we administered nebulized SCN or saline to β epithelial sodium channel (βENaC) mice, a phenotypic CF model. SCN significantly decreased airway neutrophil infiltrate and restored the redox ratio of glutathione in lung tissue and airway epithelial lining fluid to levels comparable to wild type. Furthermore, in Pseudomonas aeruginosa-infected βENaC and wild-type mice, SCN decreased inflammation, proinflammatory cytokines, and bacterial load. SCN also decreased airway neutrophil chemokine keratinocyte chemoattractant (also known as C-X-C motif chemokine ligand 1) and glutathione sulfonamide, a biomarker of granulocyte oxidative activity, in uninfected βENaC mice. Lung tissue TrxR activity and expression increased in inflamed lung tissue, providing in vivo evidence for the link between hypothiocyanous acid metabolism by TrxR and the promotion of selective biocide of pathogens. SCN treatment both suppressed inflammation and improved host defense, suggesting that nebulized SCN may have important therapeutic utility in diseases of both chronic airway inflammation and persistent bacterial infection, such as CF.
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Affiliation(s)
- Joshua D Chandler
- 1 Department of Pharmaceutical Sciences and.,Departments of 2 Medicine and
| | | | | | - Cameron S McElroy
- 1 Department of Pharmaceutical Sciences and.,Departments of 2 Medicine and
| | - Nina Dickerhof
- 3 Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch, New Zealand
| | - Tessa Mocatta
- 3 Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch, New Zealand
| | - Ashley A Fletcher
- 4 Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, Colorado
| | - Christopher M Evans
- 4 Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Aurora, Colorado
| | | | | | - Anthony J Kettle
- 3 Centre for Free Radical Research, Department of Pathology, University of Otago Christchurch, Christchurch, New Zealand
| | - David P Nichols
- Departments of 2 Medicine and.,5 Pediatrics, National Jewish Health, Denver, Colorado; and
| | - Brian J Day
- 1 Department of Pharmaceutical Sciences and.,Departments of 2 Medicine and
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15
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Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification? Int J Biol Macromol 2015; 80:162-9. [DOI: 10.1016/j.ijbiomac.2015.06.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 06/19/2015] [Accepted: 06/20/2015] [Indexed: 02/01/2023]
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16
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Khan SN, Shaeib F, Najafi T, Kavdia M, Gonik B, Saed GM, Goud PT, Abu-Soud HM. Diffused Intra-Oocyte Hydrogen Peroxide Activates Myeloperoxidase and Deteriorates Oocyte Quality. PLoS One 2015; 10:e0132388. [PMID: 26197395 PMCID: PMC4511228 DOI: 10.1371/journal.pone.0132388] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/12/2015] [Indexed: 11/30/2022] Open
Abstract
Hydrogen peroxide (H2O2) is a relatively long-lived signaling molecule that plays an essential role in oocyte maturation, implantation, as well as early embryonic development. Exposure to relatively high levels of H2O2 functions efficiently to accelerate oocyte aging and deteriorate oocyte quality. However, little precise information exists regarding intra-oocyte H2O2 concentrations, and its diffusion to the oocyte milieu. In this work, we utilized an L-shaped amperometric integrated H2O2-selective probe to directly and quantitatively measure the real-time intra-oocyte H2O2 concentration. This investigation provides an exact measurement of H2O2 in situ by reducing the possible loss of H2O2 caused by diffusion or reactivity with other biological systems. This experiment suggests that the intra-oocyte H2O2 levels of oocytes obtained from young animals are reasonably high and remained constant during the procedure measurements. However, the intra-oocyte H2O2 concentration dropped significantly (40-50% reduction) in response to catalase pre-incubation, suggesting that the measurements are truly H2O2 based. To further confirm the extracellular diffusion of H2O2, oocytes were incubated with myeloperoxidase (MPO), and the diffused H2O2 triggered MPO chlorinating activity. Our results show that the generated hypochlorous acid (HOCl) facilitated the deterioration in oocyte quality, a process that could be prevented by pre-incubating the oocytes with melatonin, which was experimentally proven to be oxidized utilizing HPLC methods. This study is the first to demonstrate direct quantitative measurement of intracellular H2O2, and its extracellular diffusion and activation of MPO as well as its impact on oocyte quality. These results may help in designing more accurate treatment plans in assisted reproduction under inflammatory conditions.
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Affiliation(s)
- Sana N. Khan
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
| | - Faten Shaeib
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
| | - Tohid Najafi
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
| | - Bernard Gonik
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
| | - Ghassan M. Saed
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
| | - Pravin T. Goud
- Department of Obstetrics and gynecology, Division of Reproductive Endocrinology and Infertility, University of California Davis, Sacramento, California, United States of America, and California IVF Fertility Center, Davis and Sacramento, California, United States of America
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, The C, S, Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
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17
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Kalász J, Pásztor ET, Fagyas M, Balogh Á, Tóth A, Csató V, Édes I, Papp Z, Borbély A. Myeloperoxidase impairs the contractile function in isolated human cardiomyocytes. Free Radic Biol Med 2015; 84:116-127. [PMID: 25770662 DOI: 10.1016/j.freeradbiomed.2015.02.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 02/02/2015] [Accepted: 02/25/2015] [Indexed: 01/09/2023]
Abstract
We set out to characterize the mechanical effects of myeloperoxidase (MPO) in isolated left-ventricular human cardiomyocytes. Oxidative myofilament protein modifications (sulfhydryl (SH)-group oxidation and carbonylation) induced by the peroxidase and chlorinating activities of MPO were additionally identified. The specificity of the MPO-evoked functional alterations was tested with an MPO inhibitor (MPO-I) and the antioxidant amino acid Met. The combined application of MPO and its substrate, hydrogen peroxide (H2O2), largely reduced the active force (Factive), increased the passive force (Fpassive), and decreased the Ca(2+) sensitivity of force production (pCa50) in permeabilized cardiomyocytes. H2O2 alone had significantly smaller effects on Factive and Fpassive and did not alter pCa50. The MPO-I blocked both the peroxidase and the chlorinating activities, whereas Met selectively inhibited the chlorinating activity of MPO. All of the MPO-induced functional effects could be prevented by the MPO-I and Met. Both H2O2 alone and MPO + H2O2 reduced the SH content of actin and increased the carbonylation of actin and myosin-binding protein C to the same extent. Neither the SH oxidation nor the carbonylation of the giant sarcomeric protein titin was affected by these treatments. MPO activation induces a cardiomyocyte dysfunction by affecting Ca(2+)-regulated active and Ca(2+)-independent passive force production and myofilament Ca(2+) sensitivity, independent of protein SH oxidation and carbonylation. The MPO-induced deleterious functional alterations can be prevented by the MPO-I and Met. Inhibition of MPO may be a promising therapeutic target to limit myocardial contractile dysfunction during inflammation.
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Affiliation(s)
- Judit Kalász
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Enikő T Pásztor
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Miklós Fagyas
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Ágnes Balogh
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Attila Tóth
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Viktória Csató
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - István Édes
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Zoltán Papp
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Attila Borbély
- Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
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18
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Narasimhulu CA, Vardhan S. Therapeutic Potential of Ocimum tenuiflorum as MPO Inhibitor with Implications for Atherosclerosis Prevention. J Med Food 2015; 18:507-15. [DOI: 10.1089/jmf.2014.0125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Sangamithra Vardhan
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
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19
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Shaeib F, Khan SN, Ali I, Najafi T, Maitra D, Abdulhamid I, Saed GM, Pennathur S, Abu-Soud HM. Melatonin prevents myeloperoxidase heme destruction and the generation of free iron mediated by self-generated hypochlorous acid. PLoS One 2015; 10:e0120737. [PMID: 25835505 PMCID: PMC4383586 DOI: 10.1371/journal.pone.0120737] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 02/06/2015] [Indexed: 12/26/2022] Open
Abstract
Myeloperoxidase (MPO) generated hypochlorous acid (HOCl) formed during catalysis is able to destroy the MPO heme moiety through a feedback mechanism, resulting in the accumulation of free iron. Here we show that the presence of melatonin (MLT) can prevent HOCl-mediated MPO heme destruction using a combination of UV-visible photometry, hydrogen peroxide (H2O2)-specific electrode, and ferrozine assay techniques. High performance liquid chromatography (HPLC) analysis showed that MPO heme protection was at the expense of MLT oxidation. The full protection of the MPO heme requires the presence of a 1:2 MLT to H2O2 ratio. Melatonin prevents HOCl-mediated MPO heme destruction through multiple pathways. These include competition with chloride, the natural co-substrate; switching the MPO activity from a two electron oxidation to a one electron pathway causing the buildup of the inactive Compound II, and its subsequent decay to MPO-Fe(III) instead of generating HOCl; binding to MPO above the heme iron, thereby preventing the access of H2O2 to the catalytic site of the enzyme; and direct scavenging of HOCl. Collectively, in addition to acting as an antioxidant and MPO inhibitor, MLT can exert its protective effect by preventing the release of free iron mediated by self-generated HOCl. Our work may establish a direct mechanistic link by which MLT exerts its antioxidant protective effect in chronic inflammatory diseases with MPO elevation.
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Affiliation(s)
- Faten Shaeib
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Sana N. Khan
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Iyad Ali
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Biochemistry and Genetics, Faculty of Medicine, An-Najah National University, Nablus, Palestine
| | - Tohid Najafi
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Dhiman Maitra
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | | | - Ghassan M. Saed
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Subramaniam Pennathur
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Husam M. Abu-Soud
- Departments of Obstetrics and Gynecology, the C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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Zhou J, Wang Q, Ding Y, Zou MH. Hypochlorous acid via peroxynitrite activates protein kinase Cθ and insulin resistance in adipocytes. J Mol Endocrinol 2015; 54:25-37. [PMID: 25381390 PMCID: PMC4261204 DOI: 10.1530/jme-14-0213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We recently reported that genetic deletion of myeloperoxidase (MPO) alleviates obesity-related insulin resistance in mice in vivo. How MPO impairs insulin sensitivity in adipocytes is poorly characterized. As hypochlorous acid (HOCl) is a principal oxidant product generated by MPO, we evaluated the effects of HOCl on insulin signaling in adipocytes differentiated from 3T3-L1 cells. Exposure of 3T3-L1 adipocytes to exogenous HOCl (200 μmol/l) attenuated insulin-stimulated 2-deoxyglucose uptake, GLUT4 translocation, and insulin signals, including tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) and phosphorylation of Akt. Furthermore, treatment with HOCl induced phosphorylation of IRS1 at serine 307, inhibitor κB kinase (IKK), c-Jun NH2-terminal kinase (JNK), and phosphorylation of PKCθ (PKCθ). In addition, genetic and pharmacological inhibition of IKK and JNK abolished serine phosphorylation of IRS1 and impairment of insulin signaling by HOCl. Furthermore, knockdown of PKCθ using siRNA transfection suppressed phosphorylation of IKK and JNK and consequently attenuated the HOCl-impaired insulin signaling pathway. Moreover, activation of PKCθ by peroxynitrite was accompanied by increased phosphorylation of IKK, JNK, and IRS1-serine 307. In contrast, ONOO(-) inhibitors abolished HOCl-induced phosphorylation of PKCθ, IKK, JNK, and IRS1-serine 307, as well as insulin resistance. Finally, high-fat diet (HFD)-induced insulin resistance was associated with enhanced phosphorylation of PKCθ, IKK, JNK, and IRS1 at serine 307 in white adipose tissues from WT mice, all of which were not found in Mpo knockout mice fed HFDs. We conclude that HOCl impairs insulin signaling pathway by increasing ONOO(-) mediated phosphorylation of PKCθ, resulting in phosphorylation of IKK/JNK and consequent serine phosphorylation of IRS1 in adipocytes.
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Affiliation(s)
- Jun Zhou
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Qilong Wang
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Ye Ding
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Ming-Hui Zou
- Section of Molecular MedicineBSEB 306A, Department of Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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21
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Maitra D, Ali I, Abdulridha RM, Shaeib F, Khan SN, Saed GM, Pennathur S, Abu-Soud HM. Kinetic studies on the reaction between dicyanocobinamide and hypochlorous acid. PLoS One 2014; 9:e110595. [PMID: 25375773 PMCID: PMC4222763 DOI: 10.1371/journal.pone.0110595] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 09/17/2014] [Indexed: 12/15/2022] Open
Abstract
Hypochlorous acid (HOCl) is a potent oxidant generated by myeloperoxidase (MPO), which is an abundant enzyme used for defense against microbes. We examined the potential role of HOCl in corrin ring destruction and subsequent formation of cyanogen chloride (CNCl) from dicyanocobinamide ((CN)2-Cbi). Stopped-flow analysis revealed that the reaction consists of at least three observable steps, including at least two sequential transient intermediates prior to corrin ring destruction. The first two steps were attributed to sequential replacement of the two cyanide ligands with hypochlorite, while the third step was the destruction of the corrin ring. The formation of (OCl)(CN)-Cbi and its conversion to (OCl)2-Cbi was fitted to a first order rate equation with second order rate constants of 0.002 and 0.0002 µM−1s−1, respectively. The significantly lower rate of the second step compared to the first suggests that the replacement of the first cyanide molecule by hypochlorite causes an alteration in the ligand trans effects changing the affinity and/or accessibility of Co toward hypochlorite. Plots of the apparent rate constants as a function of HOCl concentration for all the three steps were linear with Y-intercepts close to zero, indicating that HOCl binds in an irreversible one-step mechanism. Collectively, these results illustrate functional differences in the corrin ring environments toward binding of diatomic ligands.
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Affiliation(s)
- Dhiman Maitra
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Iyad Ali
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
- Department of Biochemistry and Genetics, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Rasha M. Abdulridha
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Faten Shaeib
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Sana N. Khan
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Ghassan M. Saed
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Subramaniam Pennathur
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States of America
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
- Department of Biochemistry and Molecular Biology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, United States of America
- * E-mail:
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22
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Abu-Soud HM, Maitra D, Shaeib F, Khan SN, Byun J, Abdulhamid I, Yang Z, Saed GM, Diamond MP, Andreana PR, Pennathur S. Disruption of heme-peptide covalent cross-linking in mammalian peroxidases by hypochlorous acid. J Inorg Biochem 2014; 140:245-54. [PMID: 25193127 PMCID: PMC4449957 DOI: 10.1016/j.jinorgbio.2014.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 12/14/2022]
Abstract
Myeloperoxidase (MPO), lactoperoxidase (LPO) and eosinophil peroxidase (EPO) play a central role in oxidative damage in inflammatory disorders by utilizing hydrogen peroxide and halides/pseudo halides to generate the corresponding hypohalous acid. The catalytic sites of these enzymes contain a covalently modified heme group, which is tethered to the polypeptide chain at two ester linkages via the methyl group (MPO, EPO and LPO) and one sulfonium bond via the vinyl group (MPO only). Covalent cross-linking of the catalytic site heme to the polypeptide chain in peroxidases is thought to play a protective role, since it renders the heme moiety less susceptible to the oxidants generated by these enzymes. Mass-spectrometric analysis revealed the following possible pathways by which hypochlorous acid (HOCl) disrupts the heme-protein cross-linking: (1) the methyl-ester bond is cleaved to form an alcohol; (2) the alcohol group undergoes an oxygen elimination reaction via the formation of an aldehyde intermediate or undergoes a demethylation reaction to lose the terminal CH2 group; and (3) the oxidative cleavage of the vinyl-sulfonium linkage. Once the heme moiety is released it undergoes cleavage at the carbon-methyne bridge either along the δ-β or a α-γ axis to form different pyrrole derivatives. These results indicate that covalent cross-linking is not enough to protect the enzymes from HOCl mediated heme destruction and free iron release. Thus, the interactions of mammalian peroxidases with HOCl modulates their activity and sets a stage for initiation of the Fenton reaction, further perpetuating oxidative damage at sites of inflammation.
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Affiliation(s)
- Husam M Abu-Soud
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA; Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| | - Dhiman Maitra
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Faten Shaeib
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Sana N Khan
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Jaeman Byun
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ibrahim Abdulhamid
- Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Zhe Yang
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ghassan M Saed
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Michael P Diamond
- Department of Obstetrics and Gynecology, Georgia Regents University, Augusta, GA 30912, USA
| | - Peter R Andreana
- The University of Toledo, Department of Chemistry and School of Green Chemistry and Engineering, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Subramaniam Pennathur
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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23
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Bafort F, Parisi O, Perraudin JP, Jijakli MH. Mode of action of lactoperoxidase as related to its antimicrobial activity: a review. Enzyme Res 2014; 2014:517164. [PMID: 25309750 PMCID: PMC4182067 DOI: 10.1155/2014/517164] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 08/19/2014] [Accepted: 08/19/2014] [Indexed: 01/11/2023] Open
Abstract
Lactoperoxidase is a member of the family of the mammalian heme peroxidases which have a broad spectrum of activity. Their best known effect is their antimicrobial activity that arouses much interest in in vivo and in vitro applications. In this context, the proper use of lactoperoxidase needs a good understanding of its mode of action, of the factors that favor or limit its activity, and of the features and properties of the active molecules. The first part of this review describes briefly the classification of mammalian peroxidases and their role in the human immune system and in host cell damage. The second part summarizes present knowledge on the mode of action of lactoperoxidase, with special focus on the characteristics to be taken into account for in vitro or in vivo antimicrobial use. The last part looks upon the characteristics of the active molecule produced by lactoperoxidase in the presence of thiocyanate and/or iodide with implication(s) on its antimicrobial activity.
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Affiliation(s)
- F. Bafort
- Plant Pathology Laboratory, Liége University, Gembloux Agro-Bio Tech, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - O. Parisi
- Plant Pathology Laboratory, Liége University, Gembloux Agro-Bio Tech, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - J.-P. Perraudin
- Taradon Laboratory, Avenue Léon Champagne 2, 1480 Tubize, Belgium
| | - M. H. Jijakli
- Plant Pathology Laboratory, Liége University, Gembloux Agro-Bio Tech, Passage des Déportés 2, 5030 Gembloux, Belgium
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24
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Maitra D, Shaeib F, Abdulhamid I, Abdulridha RM, Saed GM, Diamond MP, Pennathur S, Abu-Soud HM. Myeloperoxidase acts as a source of free iron during steady-state catalysis by a feedback inhibitory pathway. Free Radic Biol Med 2013; 63:90-8. [PMID: 23624305 PMCID: PMC3863623 DOI: 10.1016/j.freeradbiomed.2013.04.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 04/01/2013] [Accepted: 04/08/2013] [Indexed: 02/07/2023]
Abstract
Myeloperoxidase (MPO) is a heme-containing enzyme that generates hypochlorous acid (HOCl) from chloride (Cl(-)) and hydrogen peroxide (H₂O₂). It is implicated in the pathology of several chronic inflammatory conditions such as cardiovascular and pulmonary diseases and cancer. Recently we have shown that HOCl can destroy the heme prosthetic group of hemoproteins. Here, we investigated whether the HOCl formed during steady-state catalysis is able to destroy the MPO heme moiety and thereby function as a major source of free iron. UV-visible spectra and H₂O₂-specific electrode measurements recorded during steady-state HOCl synthesis by MPO showed that the degree of MPO heme destruction increased after multiple additions of H₂O₂ (10 µM), precluding the enzyme from functioning at maximum activity (80-90% inhibition). MPO heme destruction occurred only in the presence of Cl(-). Stopped-flow measurements revealed that the HOCl-mediated MPO heme destruction was complex and occurred through transient ferric species whose formation and decay kinetics indicated it participates in heme destruction along with subsequent free iron release. MPO heme depletion was confirmed by the buildup of free iron utilizing the ferrozine assay. Hypochlorous acid, once generated, first equilibrates in the solution as a whole before binding to the heme iron and initiating heme destruction. Eliminating HOCl from the MPO milieu by scavenging HOCl, destabilizing the MPO-Compound I-Cl complex that could be formed during catalysis, and/or inhibiting MPO catalytic activity partially or completely protects MPO from HOCl insults. Collectively, this study elucidates the bidirectional relationship between MPO and HOCl, which highlights the potential role of MPO as a source of free iron.
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Affiliation(s)
- Dhiman Maitra
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
| | - Faten Shaeib
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
| | | | - Rasha M. Abdulridha
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
| | - Ghassan M. Saed
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
| | - Michael P. Diamond
- Department of Obstetrics and Gynecology, Georgia Regents University, Augusta, GA 30912, USA
| | - Subramaniam Pennathur
- Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Husam M. Abu-Soud
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Corresponding author. Fax: 313 577 8554. (H. M. Abu-Soud)
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25
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Shaeib F, Banerjee J, Maitra D, Diamond MP, Abu-Soud HM. Impact of hydrogen peroxide-driven Fenton reaction on mouse oocyte quality. Free Radic Biol Med 2013; 58:154-9. [PMID: 23261938 PMCID: PMC4482232 DOI: 10.1016/j.freeradbiomed.2012.12.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/07/2012] [Accepted: 12/10/2012] [Indexed: 12/12/2022]
Abstract
Here we show that hydroxyl radical ((•)OH) generated through the Fenton reaction alters metaphase-II mouse oocyte microtubules (MT) and chromosomal alignment (CH). Metaphase-II mouse oocytes, obtained commercially, were grouped as follows: control, hydrogen peroxide (H2O2), Fe(II), and combined (Fe(II) +H2O2) treatments. After 7-10 min of incubation at 37 °C, MT and CH were evaluated on fixed and stained oocytes and scored by two blinded observers. Pearson χ(2) test and Fisher exact test were used to compare outcomes between controls and treated groups and also among the treated groups. Our results showed that poor scores for MT and CH increased significantly in oocytes treated with a combination of H2O2 and Fe(II) (p<0.001); oocytes treated with H2O2 alone or Fe(II) alone showed no or few changes compared to control. Comparison of oocyte groups that received increasing concentrations of H2O2 and a fixed amount of Fe(II) showed that 70-80% demonstrated poor scores in both MT and CH when pretreated with 5 μM H2O2, and this increased up to 90-100% when treated with 10-20 μM H2O2. Hydroxyl radical generated by H2O2-driven Fenton reaction deteriorates the metaphase-II mouse oocyte spindle and CH alignment, which is thought to be a potential cause of poor oocyte quality. Thus, free iron and/or ROS scavengers could attenuate the (•)OH-mediated spindle and chromosomal damage, thereby serving as a possible approach for further examination as a therapeutic option in inflammatory states.
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Affiliation(s)
| | | | | | | | - Husam M. Abu-Soud
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan 48201
- Address correspondence to: Husam M Abu-Soud, Ph.D Wayne State University School of Medicine, Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, 275 E. Hancock Detroit, MI 48201, Tel. 313 577-6178, Fax. 313 577-8554,
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Chandler JD, Nichols DP, Nick JA, Hondal RJ, Day BJ. Selective metabolism of hypothiocyanous acid by mammalian thioredoxin reductase promotes lung innate immunity and antioxidant defense. J Biol Chem 2013; 288:18421-8. [PMID: 23629660 DOI: 10.1074/jbc.m113.468090] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The endogenously produced oxidant hypothiocyanous acid (HOSCN) inhibits and kills pathogens but paradoxically is well tolerated by mammalian host tissue. Mammalian high molecular weight thioredoxin reductase (H-TrxR) is evolutionarily divergent from bacterial low molecular weight thioredoxin reductase (L-TrxR). Notably, mammalian H-TrxR contains a selenocysteine (Sec) and has wider substrate reactivity than L-TrxR. Recombinant rat cytosolic H-TrxR1, mouse mitochondrial H-TrxR2, and a purified mixture of both from rat selectively turned over HOSCN (kcat = 357 ± 16 min(-1); Km = 31.9 ± 10.3 μM) but were inactive against the related oxidant hypochlorous acid. Replacing Sec with Cys or deleting the final eight C-terminal peptides decreased affinity and turnover of HOSCN by H-TrxR. Similarly, glutathione reductase (an H-TrxR homologue lacking Sec) was less effective at HOSCN turnover. In contrast to H-TrxR and glutathione reductase, recombinant Escherichia coli L-TrxR was potently inhibited by HOSCN (IC50 = 2.75 μM). Similarly, human bronchial epithelial cell (16HBE) lysates metabolized HOSCN, but E. coli and Pseudomonas aeruginosa lysates had little or no activity. HOSCN selectively produced toxicity in bacteria, whereas hypochlorous acid was nonselectively toxic to both bacteria and 16HBE. Treatment with the H-TrxR inhibitor auranofin inhibited HOSCN metabolism in 16HBE lysates and significantly increased HOSCN-mediated cytotoxicity. These findings demonstrate both the metabolism of HOSCN by mammalian H-TrxR resulting in resistance to HOSCN in mammalian cells and the potent inhibition of bacterial L-TrxR resulting in cytotoxicity in bacteria. These data support a novel selective mechanism of host defense in mammals wherein HOSCN formation simultaneously inhibits pathogens while sparing host tissue.
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Affiliation(s)
- Joshua D Chandler
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, Colorado 80045, USA
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Cook NL, Pattison DI, Davies MJ. Myeloperoxidase-derived oxidants rapidly oxidize and disrupt zinc-cysteine/histidine clusters in proteins. Free Radic Biol Med 2012; 53:2072-80. [PMID: 23032100 DOI: 10.1016/j.freeradbiomed.2012.09.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/29/2012] [Accepted: 09/25/2012] [Indexed: 01/15/2023]
Abstract
Zinc is an abundant cellular transition metal ion, which binds avidly to protein cysteine (Cys) and histidine (His) residues to form zinc-Cys/His clusters; these play a key role in the function of many proteins (e.g., DNA binding and repair enzymes, transcription factors, nitric oxide synthase). Leukocyte-derived myeloperoxidase generates powerful oxidants including hypochlorous (HOCl), hypobromous (HOBr), and hypothiocyanous (HOSCN) acids from H(2)O(2) and (pseudo)halide ions. Excessive or misplaced formation of these species is associated with cellular dysfunction, apoptosis and necrosis, and multiple inflammatory diseases. HOCl and HOBr react rapidly with sulfur-containing compounds, and HOSCN reacts specifically with thiols. Consequently, we hypothesized that zinc-Cys/His clusters would be targets for these oxidants, and the activity of such enzymes would be perturbed. This hypothesis has been tested using yeast alcohol dehydrogenase (YADH), which contains a well-characterized Zn(1)Cys(2)His(1) cluster. Incubation of YADH with pathologically relevant concentrations of HOSCN, HOCl, and HOBr resulted in rapid oxidation of the protein (rate constants, determined by competition kinetics, for reaction of HOCl and HOSCN with YADH being (3.3±0.9)×10(8) and (2.9±0.4)×10(4) M(-1) s(-1) per YADH monomer, respectively), loss of enzyme activity, Zn(2+) release, changes in protein structure (particularly formation of disulfide cross-links), and oxidation of Cys residues. The loss of enzyme activity correlated with Zn(2+) release, loss of thiols, and changes in protein structure. We conclude that exposure of zinc-Cys/His clusters to inflammatory oxidants can result in impaired protein activity, thiol oxidation, and Zn(2+) release. These reactions may contribute to inflammation-induced tissue damage.
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Affiliation(s)
- Naomi L Cook
- The Heart Research Institute, Newtown, Sydney, NSW 2042, Australia
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Banerjee J, Maitra D, Diamond MP, Abu-Soud HM. Melatonin prevents hypochlorous acid-induced alterations in microtubule and chromosomal structure in metaphase-II mouse oocytes. J Pineal Res 2012; 53:122-8. [PMID: 22304486 DOI: 10.1111/j.1600-079x.2012.00977.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hypochlorous acid (HOCl) is generated by myeloperoxidase, using chloride and hydrogen peroxide as substrates. Here we demonstrate that HOCl alters metaphase-II mouse oocyte microtubules and chromosomal (CH) alignment which can be prevented by melatonin. Metaphase-II mouse oocytes, obtained commercially, were grouped as: control, melatonin (150, 200nmol/mL), HOCl (10, 20, 50, and 100nmol/mL), and HOCl (50nmol/mL) pretreated with 150 and 200 nmol/mL of melatonin. Microtubule and CH alignment was studied utilizing an indirect immunofluorescence technique and scored by two observers. Pearson chi-square test and Fisher's exact test were used to compare outcomes between controls and treated groups and also among each group. Poor scores for the spindle and chromosomes increased significantly at 50nmol/mL of HOCl (P<0.001). Oocytes treated with melatonin only at 150 and 200 nmol/mL showed no changes; significant differences (P<0.001) were observed when oocytes exposed to 50nmol/mL of HOCl were compared to oocytes pretreated with 200 nmol/mL melatonin. Fifty percent of the oocytes demonstrated good scores, both in microtubule and CH alterations, when pretreated with melatonin at 150 nmol/mL compared to 0% in the HOCl-only group. HOCl alters the metaphase-II mouse oocyte spindle and CH alignment in a dose-dependant manner, which might be a potential cause of poor oocyte quality (e.g., in patients with endometriosis). Melatonin prevented the HOCl-mediated spindle and CH damage, and therefore, may be an attractive therapeutic option to prevent oocyte damage in endometriosis or inflammatory diseases where HOCl levels are known to be elevated.
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Affiliation(s)
- Jashoman Banerjee
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Detroit, MI 48201, USA
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Maitra D, Abdulhamid I, Diamond MP, Saed GM, Abu-Soud HM. Melatonin attenuates hypochlorous acid-mediated heme destruction, free iron release, and protein aggregation in hemoglobin. J Pineal Res 2012; 53:198-205. [PMID: 22462755 DOI: 10.1111/j.1600-079x.2012.00988.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In inflammatory diseases, where hypochlorous acid (HOCl) is elevated, iron homeostasis is disturbed, resulting in accumulation of free iron. Free iron is toxic by virtue of its ability to generate free radicals through the Fenton reaction. HOCl is generated by myeloperoxidase, (MPO) using chloride and hydrogen peroxide as substrates. Recent studies demonstrate that HOCl binds to the heme moiety of hemoglobin (Hb), which generates a transient ferric species whose formation and decay kinetics indicate it participates in protein aggregation, heme destruction, and free iron release. Here, we show that melatonin prevents HOCl-mediated Hb heme destruction and protein aggregation, using a combination of UV-vis spectrophotometry, ferrozine colorimetric assay, and in-gel heme staining. We also show that melatonin treatment prevents HOCl-mediated loss of red blood cell (RBC) viability, indicating biologic relevance of this finding. The mechanism by which melatonin prevents HOCl-mediated Hb heme destruction is by direct scavenging of HOCl and/or through the destabilization of the higher Hb oxidative states intermediates, ferryl porphyrin radical cation Hb-Fe(IV)=O(+π•) and Hb-Fe(IV)=O, which are formed through the reaction of HOCl with Hb. Our work establishes a direct mechanistic link between melatonin and its protective effect in chronic inflammatory diseases. Collectively, in addition to acting as an antioxidant and as a MPO inhibitor, melatonin can also exert its protective effect by inhibiting HOCl-mediated heme destruction of hemoproteins and subsequent free iron release.
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Affiliation(s)
- Dhiman Maitra
- Department of Obstetrics and Gynecology, The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Gebendorfer KM, Drazic A, Le Y, Gundlach J, Bepperling A, Kastenmüller A, Ganzinger KA, Braun N, Franzmann TM, Winter J. Identification of a hypochlorite-specific transcription factor from Escherichia coli. J Biol Chem 2012; 287:6892-903. [PMID: 22223481 DOI: 10.1074/jbc.m111.287219] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypochlorite is a powerful oxidant produced by neutrophils to kill invading microorganisms. Despite this important physiological role of HOCl in fighting bacterial infections, no hypochlorite-specific stress response has been identified yet. Here, we identified a hypochlorite-responsive transcription factor, YjiE, which is conserved in proteobacteria and eukaryotes. YjiE forms unusual dodecameric ring-like structures in vitro that undergo large DNA-induced conformational changes to form dimers and tetramers as shown by transmission electron microscopy and analytical ultracentrifugation. Such smaller oligomers are predominant in hypochlorite-stressed cells and are the active species as shown by fluorescence anisotropy and analytical ultracentrifugation. YjiE regulates a large number of genes upon hypochlorite stress. Among them are genes involved in cysteine, methionine biosynthesis, and sulfur metabolism (up-regulated) and genes involved in iron acquisition and homeostasis (down-regulated), thus supposedly replenishing oxidized metabolites and decreasing the hypochlorite-mediated amplification of intracellular reactive oxygen species. As a result, YjiE specifically confers hypochlorite resistance to E. coli cells. Thus, to our knowledge, YjiE is the first described hypochlorite-specific transcription factor.
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Affiliation(s)
- Katharina M Gebendorfer
- Section of Biotechnology, Department of Chemistry, Center for Integrated Protein Science Munich, Technische Universität München, 85747 Garching, Germany
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