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Benchoam D, Cuevasanta E, Roman JV, Banerjee R, Alvarez B. Acidity of persulfides and its modulation by the protein environments in sulfide quinone oxidoreductase and thiosulfate sulfurtransferase. J Biol Chem 2024; 300:107149. [PMID: 38479599 PMCID: PMC11039317 DOI: 10.1016/j.jbc.2024.107149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 02/12/2024] [Accepted: 02/28/2024] [Indexed: 04/23/2024] Open
Abstract
Persulfides (RSSH/RSS-) participate in sulfur metabolism and are proposed to transduce hydrogen sulfide (H2S) signaling. Their biochemical properties are poorly understood. Herein, we studied the acidity and nucleophilicity of several low molecular weight persulfides using the alkylating agent, monobromobimane. The different persulfides presented similar pKa values (4.6-6.3) and pH-independent rate constants (3.2-9.0 × 103 M-1 s-1), indicating that the substituents in persulfides affect properties to a lesser extent than in thiols because of the larger distance to the outer sulfur. The persulfides had higher reactivity with monobromobimane than analogous thiols and putative thiols with the same pKa, providing evidence for the alpha effect (enhanced nucleophilicity by the presence of a contiguous atom with high electron density). Additionally, we investigated two enzymes from the human mitochondrial H2S oxidation pathway that form catalytic persulfide intermediates, sulfide quinone oxidoreductase and thiosulfate sulfurtransferase (TST, rhodanese). The pH dependence of the activities of both enzymes was measured using sulfite and/or cyanide as sulfur acceptors. The TST half-reactions were also studied by stopped-flow fluorescence spectroscopy. Both persulfidated enzymes relied on protonated groups for reaction with the acceptors. Persulfidated sulfide quinone oxidoreductase appeared to have a pKa of 7.8 ± 0.2. Persulfidated TST presented a pKa of 9.38 ± 0.04, probably due to a critical active site residue rather than the persulfide itself. The TST thiol reacted in the anionic state with thiosulfate, with an apparent pKa of 6.5 ± 0.1. Overall, our study contributes to a fundamental understanding of persulfide properties and their modulation by protein environments.
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Affiliation(s)
- Dayana Benchoam
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Graduate Program in Chemistry, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Ernesto Cuevasanta
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Unidad de Bioquímica Analítica, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Joseph V Roman
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Beatriz Alvarez
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay.
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Benchoam D, Cuevasanta E, Semelak JA, Mastrogiovanni M, Estrin DA, Möller MN, Alvarez B. Disulfides form persulfides at alkaline pH leading to potential overestimations in the cold cyanolysis method. Free Radic Biol Med 2023; 207:63-71. [PMID: 37421993 DOI: 10.1016/j.freeradbiomed.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/30/2023] [Accepted: 07/05/2023] [Indexed: 07/10/2023]
Abstract
It is well established that proteins and peptides can release sulfur under alkaline treatment, mainly through the β-elimination of disulfides with the concomitant formation of persulfides and dehydroalanine derivatives. In this study, we evaluated the formation of glutathione persulfide (GSSH/GSS-) by exposure of glutathione disulfide (GSSG) to alkaline conditions. The kinetics of the reaction between GSSG and HO- was investigated by UV-Vis absorbance, reaction with 5,5'-dithio-bis-(2-nitrobenzoic acid) (DTNB), and cold cyanolysis, obtaining an apparent second-order rate constant of ∼10-3 M-1 s-1 at 25 °C. The formation of GSSH and the dehydroalanine derivative was confirmed by HPLC and/or mass spectrometry. However, the mixtures did not equilibrate in a timescale of hours, and additional species, including thiol and diverse sulfane sulfur compounds were also formed, probably through further reactions of the persulfide. Cold cyanolysis is frequently used to quantify persulfides, since it measures sulfane sulfur. This method involves a step in which the sample to be analyzed is incubated with cyanide at alkaline pH. When cold cyanolysis was applied to samples containing GSSG, sulfane sulfur products that were not present in the original sample were measured. Thus, our results reveal the risk of overestimating the amount of sulfane sulfur compounds in samples that contain disulfides due to their decay to persulfides and other sulfane sulfur compounds at alkaline pH. Overall, our study highlights that the β-elimination of disulfides is a potential source of persulfides, although we do not recommend the preparation of GSSH from incubation of GSSG in alkali. Our study also highlights the importance of being cautious when doing and interpreting cold cyanolysis experiments.
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Affiliation(s)
- Dayana Benchoam
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, 11800, Uruguay; Graduate Program in Chemistry, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Ernesto Cuevasanta
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, 11800, Uruguay; Unidad de Bioquímica Analítica, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay
| | - Jonathan A Semelak
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires, 1428, Argentina
| | - Mauricio Mastrogiovanni
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, 11800, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, 11800, Uruguay
| | - Darío A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires, 1428, Argentina
| | - Matías N Möller
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, 11800, Uruguay; Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay
| | - Beatriz Alvarez
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, 11800, Uruguay.
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Kämpf S, Fenk S, Van Cromvoirt A, Bogdanov N, Hartnack S, Stirn M, Hofmann-Lehmann R, Reichler IM, Bogdanova A. Differences in selected blood parameters between brachycephalic and non-brachycephalic dogs. Front Vet Sci 2023; 10:1166032. [PMID: 37649563 PMCID: PMC10464621 DOI: 10.3389/fvets.2023.1166032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/11/2023] [Indexed: 09/01/2023] Open
Abstract
Introduction Cranial and upper-airway anatomy of short-nosed, flat-faced brachycephalic dogs predisposes them to brachycephalic obstructive airway syndrome (BOAS). Periodic apnoea increased inspiratory resistance, and an inability to thermoregulate effectively are characteristic of BOAS, but internationally accepted objective markers of BOAS severity are missing. The objective of this study was to compare the selected blood parameters between non-brachycephalic (NC) and brachycephalic (BC) dogs, exploring the possibility of developing a blood test for BOAS severity grading in the future. Methods We evaluated blood biochemistry, complete blood cell counts, red blood cell (RBC) indices, reticulocyte counts, a blood-born marker of intermittent hypoxia (glutathione, NO production), RBC hydration, deformability, and blood markers of metabolic changes and stress between BC (n = 18) and NC (meso- and dolichocephalic, n = 22) dogs. Results Reticulocyte counts and the abundance of middle-fluorescence immature reticulocytes were significantly (p < 0.05) higher in BC dogs compared to NC dogs. BC dogs had significantly more NO-derived NO2 - /NO3 - in plasma than NC dogs. RBCs of BC dogs were shedding significantly more membrane, as follows from the intensity of eosin maleimide staining, and had a significantly higher mean corpuscular hemoglobin concentration than NC dogs. Intracellular reduced glutathione content in RBCs of BC dogs was significantly lower, while plasma lactate was significantly higher in BC dogs compared to NC dogs. Plasma cholesterol and triglycerides were significantly lower, and cortisol was significantly higher in BC dogs compared to NC dogs. Eosinophil counts were significantly lower and the neutrophil-to-lymphocyte ratio was higher in BC dogs compared to NC dogs. Discussion Taken together, our findings suggest that the brachycephalic phenotype in dogs is associated with alterations at the level of blood cells and, systemically, with oxidation and metabolic changes. The parameters identified within this study should be further investigated for their potential as objective indicators for BOAS.
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Affiliation(s)
- Sandra Kämpf
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Simone Fenk
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Ankie Van Cromvoirt
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Nikolay Bogdanov
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Sonja Hartnack
- Section of Epidemiology, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Martina Stirn
- Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Regina Hofmann-Lehmann
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
- Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Iris Margaret Reichler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Anna Bogdanova
- Red Blood Cell Research Group, Institute of Veterinary Physiology, Faculty of Vetsuisse, University of Zurich, Zürich, Switzerland
- Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
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Fenk S, Melnikova EV, Anashkina AA, Poluektov YM, Zaripov PI, Mitkevich VA, Tkachev YV, Kaestner L, Minetti G, Mairbäurl H, Goede JS, Makarov AA, Petrushanko IY, Bogdanova A. Hemoglobin is an oxygen-dependent glutathione buffer adapting the intracellular reduced glutathione levels to oxygen availability. Redox Biol 2022; 58:102535. [PMID: 36413919 PMCID: PMC9679038 DOI: 10.1016/j.redox.2022.102535] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/21/2022] [Accepted: 11/08/2022] [Indexed: 11/17/2022] Open
Abstract
Fast changes in environmental oxygen availability translate into shifts in mitochondrial free radical production. An increase in intraerythrocytic reduced glutathione (GSH) during deoxygenation would support the detoxification of exogenous oxidants released into the circulation from hypoxic peripheral tissues. Although reported, the mechanism behind this acute oxygen-dependent regulation of GSH in red blood cells remains unknown. This study explores the role of hemoglobin (Hb) in the oxygen-dependent modulation of GSH levels in red blood cells. We have demonstrated that a decrease in Hb O2 saturation to 50% or less observed in healthy humans while at high altitude, or in red blood cell suspensions results in rising of the intraerythrocytic GSH level that is proportional to the reduction in Hb O2 saturation. This effect was not caused by the stimulation of GSH de novo synthesis or its release during deglutathionylation of Hb's cysteines. Using isothermal titration calorimetry and in silico modeling, we observed the non-covalent binding of four molecules of GSH to oxy-Hb and the release of two of them upon deoxygenation. Localization of the GSH binding sites within the Hb molecule was identified. Oxygen-dependent binding of GSH to oxy-Hb and its release upon deoxygenation occurred reciprocally to the binding and release of 2,3-bisphosphoglycerate. Furthermore, noncovalent binding of GSH to Hb moderately increased Hb oxygen affinity. Taken together, our findings have identified an adaptive mechanism by which red blood cells may provide an advanced antioxidant defense to respond to oxidative challenges immediately upon deoxygenation.
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Affiliation(s)
- Simone Fenk
- Red Blood Cell Research Group, Institute of Veterinary Physiology, and Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Elizaveta V Melnikova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Anastasia A Anashkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Yuri M Poluektov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Pavel I Zaripov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Vladimir A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Yaroslav V Tkachev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Lars Kaestner
- Theoretical Medicine and Biosciences and Experimental Physics, Dynamics of Fluids Group, Saarland University, Saarland and Homburg, Germany
| | - Giampaolo Minetti
- Department of Biology and Biotechnology "L Spallanzani", Laboratories of Biochemistry, University of Pavia, Italy
| | - Heimo Mairbäurl
- Medical Clinic VII, Sports Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jeroen S Goede
- Department of Internal Medicine, Division of Oncology and Hematology, Cantonal Hospital Winterthur, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Switzerland
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Irina Yu Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Anna Bogdanova
- Red Blood Cell Research Group, Institute of Veterinary Physiology, and Center for Clinical Studies (ZKS), Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), Switzerland.
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Luo S, Liang C, Zhang Q, Zhang P. Iridium photosensitizer constructed liposomes with hypoxia-activated prodrug to destrust hepatocellular carcinoma. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Mehlenbacher MR, Elsiesy R, Lakha R, Villones RLE, Orman M, Vizcarra CL, Meloni G, Wilcox DE, Austin RN. Metal binding and interdomain thermodynamics of mammalian metallothionein-3: enthalpically favoured Cu + supplants entropically favoured Zn 2+ to form Cu 4 + clusters under physiological conditions. Chem Sci 2022; 13:5289-5304. [PMID: 35655557 PMCID: PMC9093145 DOI: 10.1039/d2sc00676f] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/01/2022] [Indexed: 01/02/2023] Open
Abstract
Metallothioneins (MTs) are a ubiquitous class of small metal-binding proteins involved in metal homeostasis and detoxification. While known for their high affinity for d10 metal ions, there is a surprising dearth of thermodynamic data on metals binding to MTs. In this study, Zn2+ and Cu+ binding to mammalian metallothionein-3 (MT-3) were quantified at pH 7.4 by isothermal titration calorimetry (ITC). Zn2+ binding was measured by chelation titrations of Zn7MT-3, while Cu+ binding was measured by Zn2+ displacement from Zn7MT-3 with competition from glutathione (GSH). Titrations in multiple buffers enabled a detailed analysis that yielded condition-independent values for the association constant (K) and the change in enthalpy (ΔH) and entropy (ΔS) for these metal ions binding to MT-3. Zn2+ was also chelated from the individual α and β domains of MT-3 to quantify the thermodynamics of inter-domain interactions in metal binding. Comparative titrations of Zn7MT-2 with Cu+ revealed that both MT isoforms have similar Cu+ affinities and binding thermodynamics, indicating that ΔH and ΔS are determined primarily by the conserved Cys residues. Inductively coupled plasma mass spectrometry (ICP-MS) analysis and low temperature luminescence measurements of Cu-replete samples showed that both proteins form two Cu4 +-thiolate clusters when Cu+ displaces Zn2+ under physiological conditions. Comparison of the Zn2+ and Cu+ binding thermodynamics reveal that enthalpically-favoured Cu+, which forms Cu4 +-thiolate clusters, displaces the entropically-favoured Zn2+. These results provide a detailed thermodynamic analysis of d10 metal binding to these thiolate-rich proteins and quantitative support for, as well as molecular insight into, the role that MT-3 plays in the neuronal chemistry of copper.
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Affiliation(s)
| | - Rahma Elsiesy
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Rabina Lakha
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Rhiza Lyne E Villones
- Department of Chemistry and Biochemistry, University of Texas at Dallas Richardson TX 75080 USA
| | - Marina Orman
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Christina L Vizcarra
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Gabriele Meloni
- Department of Chemistry and Biochemistry, University of Texas at Dallas Richardson TX 75080 USA
| | - Dean E Wilcox
- Department of Chemistry, Dartmouth College Hanover NH 03755 USA
| | - Rachel N Austin
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
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Kim GH, Cha DH, Nepal MR, Jeong TC. A convenient fluorometric test method for skin sensitization using glutathione in chemico. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2021; 84:783-799. [PMID: 34196263 DOI: 10.1080/15287394.2021.1944939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A convenient fluorometrical test method to identify skin sensitizers in chemico was developed using reactivity with glutathione (GSH), a low molecular weight endogenous substance. Following incubation of test chemicals with GSH, the remaining GSH was quantitated fluorometrically by using monobromobimane (mBBr), a thiol-detecting agent, for determining % depletion of this endogenous substance by test chemicals. The experimental conditions optimized were: (1) reactivity of thiol compounds including GSH with mBBr, (2) effects of vehicles on reactivity, (3) molar ratios of GSH to test chemicals, and (4) reactivity of endogenous substance with test substances under different incubation times. When an optimized condition with DMSO as a vehicle for test chemicals and in 1:60 ratio for 24 hr at 4°C was applied to classify 48 well-known skin sensitizers and non-sensitizers, the predictive capacity was as follows: 88.2% sensitivity, 78.6% specificity, and 85.4% accuracy with 95.8% consistency of three trials when 10.3% depletion of GSH was used as a cutoff value. Because the present method employed relatively simple GSH as an acceptor for sensitizers and/or a relatively convenient fluorometric detection system in 96-well plates for a high throughput test, it would be a useful test tool for screening skin sensitization potential of test chemicals.
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Affiliation(s)
- Geon Ho Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, South Korea
| | - Dong Ho Cha
- College of Pharmacy, Yeungnam University, Gyeongsan, South Korea
| | - Mahesh R Nepal
- College of Pharmacy, Yeungnam University, Gyeongsan, South Korea
| | - Tae Cheon Jeong
- College of Pharmacy, Yeungnam University, Gyeongsan, South Korea
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Horsfall AJ, McDougal DP, Scanlon DB, Bruning JB, Abell AD. Approaches to Introduce Helical Structure in Cysteine-Containing Peptides with a Bimane Group. Chembiochem 2021; 22:2711-2720. [PMID: 34107164 DOI: 10.1002/cbic.202100241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/08/2021] [Indexed: 01/01/2023]
Abstract
An i-i+4 or i-i+3 bimane-containing linker was introduced into a peptide known to target Estrogen Receptor alpha (ERα), in order to stabilise an α-helical geometry. These macrocycles were studied by CD and NMR to reveal the i-i+4 constrained peptide adopts a 310 -helical structure in solution, and an α-helical conformation on interaction with the ERα coactivator recruitment surface in silico. An acyclic bimane-modified peptide is also helical, when it includes a tryptophan or tyrosine residue; but is significantly less helical with a phenylalanine or alanine residue, which indicates such a bimane modification influences peptide structure in a sequence dependent manner. The fluorescence intensity of the bimane appears influenced by peptide conformation, where helical peptides displayed a fluorescence increase when TFE was added to phosphate buffer, compared to a decrease for less helical peptides. This study presents the bimane as a useful modification to influence peptide structure as an acyclic peptide modification, or as a side-chain constraint to give a macrocycle.
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Affiliation(s)
- Aimee J Horsfall
- ARC Centre of Excellence for Nanoscale Biophotonics (CNBP), University of Adelaide, Adelaide, SA 5005, Australia.,Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.,The Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA 5005, Australia
| | - Daniel P McDougal
- The Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA 5005, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Denis B Scanlon
- Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.,The Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA 5005, Australia
| | - John B Bruning
- The Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA 5005, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Andrew D Abell
- ARC Centre of Excellence for Nanoscale Biophotonics (CNBP), University of Adelaide, Adelaide, SA 5005, Australia.,Department of Chemistry, University of Adelaide, Adelaide, SA 5005, Australia.,The Institute for Photonics & Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA 5005, Australia
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9
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Benchoam D, Semelak JA, Cuevasanta E, Mastrogiovanni M, Grassano JS, Ferrer-Sueta G, Zeida A, Trujillo M, Möller MN, Estrin DA, Alvarez B. Acidity and nucleophilic reactivity of glutathione persulfide. J Biol Chem 2020; 295:15466-15481. [PMID: 32873707 DOI: 10.1074/jbc.ra120.014728] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/17/2020] [Indexed: 12/22/2022] Open
Abstract
Persulfides (RSSH/RSS-) participate in sulfur trafficking and metabolic processes, and are proposed to mediate the signaling effects of hydrogen sulfide (H2S). Despite their growing relevance, their chemical properties are poorly understood. Herein, we studied experimentally and computationally the formation, acidity, and nucleophilicity of glutathione persulfide (GSSH/GSS-), the derivative of the abundant cellular thiol glutathione (GSH). We characterized the kinetics and equilibrium of GSSH formation from glutathione disulfide and H2S. A pKa of 5.45 for GSSH was determined, which is 3.49 units below that of GSH. The reactions of GSSH with the physiologically relevant electrophiles peroxynitrite and hydrogen peroxide, and with the probe monobromobimane, were studied and compared with those of thiols. These reactions occurred through SN2 mechanisms. At neutral pH, GSSH reacted faster than GSH because of increased availability of the anion and, depending on the electrophile, increased reactivity. In addition, GSS- presented higher nucleophilicity with respect to a thiolate with similar basicity. This can be interpreted in terms of the so-called α effect, i.e. the increased reactivity of a nucleophile when the atom adjacent to the nucleophilic atom has high electron density. The magnitude of the α effect correlated with the Brønsted nucleophilic factor, βnuc, for the reactions with thiolates and with the ability of the leaving group. Our study constitutes the first determination of the pKa of a biological persulfide and the first examination of the α effect in sulfur nucleophiles, and sheds light on the chemical basis of the biological properties of persulfides.
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Affiliation(s)
- Dayana Benchoam
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Jonathan A Semelak
- Departamento de Química Inorgánica, Analítica y Química Física, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and CONICET, Argentina
| | - Ernesto Cuevasanta
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Unidad de Bioquímica Analítica, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Mauricio Mastrogiovanni
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Juan S Grassano
- Departamento de Química Inorgánica, Analítica y Química Física, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and CONICET, Argentina
| | - Gerardo Ferrer-Sueta
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ari Zeida
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Matías N Möller
- Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay; Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
| | - Darío A Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and CONICET, Argentina.
| | - Beatriz Alvarez
- Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay.
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10
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Horsfall AJ, Dunning KR, Keeling KL, Scanlon DB, Wegener KL, Abell AD. A Bimane‐Based Peptide Staple for Combined Helical Induction and Fluorescent Imaging. Chembiochem 2020; 21:3423-3432. [DOI: 10.1002/cbic.202000485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Aimee J. Horsfall
- The Department of Chemistry, School of Physical Sciences The University of Adelaide North Terrace Adelaide SA 5005 Australia
- The ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
| | - Kylie R. Dunning
- The ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Robinson Research Institute, Adelaide Medical School The University of Adelaide North Terrace Adelaide SA 5005 Australia
| | - Kelly L. Keeling
- The Department of Chemistry, School of Physical Sciences The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
| | - Denis B. Scanlon
- The Department of Chemistry, School of Physical Sciences The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
| | - Kate L. Wegener
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
- School of Biological Sciences The University of Adelaide North Terrace Adelaide SA 5005 Australia
| | - Andrew D. Abell
- The Department of Chemistry, School of Physical Sciences The University of Adelaide North Terrace Adelaide SA 5005 Australia
- The ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP) The University of Adelaide North Terrace Adelaide SA 5005 Australia
- Institute for Photonics and Advanced Sensing (IPAS) The University of Adelaide North Terrace Adelaide SA 5005 Australia
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11
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Marvian AT, Aliakbari F, Mohammad-Beigi H, Ahmadi ZA, Mehrpooyan S, Lermyte F, Nasouti M, Collingwood JF, Otzen DE, Morshedi D. The status of the terminal regions of α-synuclein in different forms of aggregates during fibrillization. Int J Biol Macromol 2020; 155:543-550. [PMID: 32240735 DOI: 10.1016/j.ijbiomac.2020.03.238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 10/24/2022]
Abstract
The α-synuclein (αSN) amyloid fibrillization process is known to be a crucial phenomenon associated with neuronal loss in various neurodegenerative diseases, most famously Parkinson's disease. The process involves different aggregated species and ultimately leads to formation of β-sheet rich fibrillar structures. Despite the essential role of αSN aggregation in the pathoetiology of various neurological disorders, the characteristics of various assemblies are not fully understood. Here, we established a fluorescence-based model for studying the end-parts of αSN to decipher the structural aspects of aggregates during the fibrillization. Our model proved highly sensitive to the events at the early stage of the fibrillization process, which are hardly detectable with routine techniques. Combining fluorescent and PAGE analysis, we found different oligomeric aggregates in the nucleation phase of fibrillization with different sensitivity to SDS and different structures based on αSN termini. Moreover, we found that these oligomers are highly dynamic: after reaching peak levels during fibrillization, they decline and eventually disappear, suggesting their transformation into other αSN aggregated species. These findings shed light on the structural features of various αSN aggregates and their dynamics in synucleinopathies.
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Affiliation(s)
- Amir Tayaranian Marvian
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran; Department of Neurology, School of Medicine, Technical University of Munich, Munich, Germany; Department of Translational Neurodegeneration, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Farhang Aliakbari
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran; Interdisciplinary Nanoscience Centre (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Hossein Mohammad-Beigi
- Interdisciplinary Nanoscience Centre (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Zeinab Alsadat Ahmadi
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Sina Mehrpooyan
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | | | - Mahour Nasouti
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | | | - Daniel E Otzen
- Interdisciplinary Nanoscience Centre (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Dina Morshedi
- Bioprocess Engineering Department, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
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12
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Bogdanova A, Kaestner L, Simionato G, Wickrema A, Makhro A. Heterogeneity of Red Blood Cells: Causes and Consequences. Front Physiol 2020; 11:392. [PMID: 32457644 PMCID: PMC7221019 DOI: 10.3389/fphys.2020.00392] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/02/2020] [Indexed: 12/21/2022] Open
Abstract
Mean values of hematological parameters are currently used in the clinical laboratory settings to characterize red blood cell properties. Those include red blood cell indices, osmotic fragility test, eosin 5-maleimide (EMA) test, and deformability assessment using ektacytometry to name a few. Diagnosis of hereditary red blood cell disorders is complemented by identification of mutations in distinct genes that are recognized "molecular causes of disease." The power of these measurements is clinically well-established. However, the evidence is growing that the available information is not enough to understand the determinants of severity of diseases and heterogeneity in manifestation of pathologies such as hereditary hemolytic anemias. This review focuses on an alternative approach to assess red blood cell properties based on heterogeneity of red blood cells and characterization of fractions of cells with similar properties such as density, hydration, membrane loss, redox state, Ca2+ levels, and morphology. Methodological approaches to detect variance of red blood cell properties will be presented. Causes of red blood cell heterogeneity include cell age, environmental stress as well as shear and metabolic stress, and multiple other factors. Heterogeneity of red blood cell properties is also promoted by pathological conditions that are not limited to the red blood cells disorders, but inflammatory state, metabolic diseases and cancer. Therapeutic interventions such as splenectomy and transfusion as well as drug administration also impact the variance in red blood cell properties. Based on the overview of the studies in this area, the possible applications of heterogeneity in red blood cell properties as prognostic and diagnostic marker commenting on the power and selectivity of such markers are discussed.
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Affiliation(s)
- Anna Bogdanova
- Red Blood Cell Research Group, Vetsuisse Faculty, The Zurich Center for Integrative Human Physiology (ZHIP), Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
| | - Lars Kaestner
- Experimental Physics, Dynamics of Fluids, Faculty of Natural Sciences and Technology, Saarland University, Saarbrücken, Germany
- Theoretical Medicine and Biosciences, Medical Faculty, Saarland University, Homburg, Germany
| | - Greta Simionato
- Experimental Physics, Dynamics of Fluids, Faculty of Natural Sciences and Technology, Saarland University, Saarbrücken, Germany
- Institute for Clinical and Experimental Surgery, Saarland University, Homburg, Germany
| | - Amittha Wickrema
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, United States
| | - Asya Makhro
- Red Blood Cell Research Group, Vetsuisse Faculty, The Zurich Center for Integrative Human Physiology (ZHIP), Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
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13
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Savion N, Dahamshi S, Morein M, Kotev-Emeth S. S-Allylmercapro- N-Acetylcysteine Attenuates the Oxidation-Induced Lens Opacification and Retinal Pigment Epithelial Cell Death In Vitro. Antioxidants (Basel) 2019; 8:antiox8010025. [PMID: 30654434 PMCID: PMC6357052 DOI: 10.3390/antiox8010025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 01/13/2019] [Accepted: 01/15/2019] [Indexed: 12/15/2022] Open
Abstract
The capacity of S-Allylmercapto-N-acetylcysteine (ASSNAC) to protect human retinal pigment epithelial (RPE) cells (line ARPE-19) and porcine lenses from oxidative stress was studied. Confluent ARPE-19 cultures were incubated with ASSNAC or N-acetyl-cysteine (NAC) followed by exposure to oxidants and glutathione level and cell survival were determined. Porcine lenses were incubated with ASSNAC and then exposed to H2O2 followed by lens opacity measurement and determination of glutathione (reduced (GSH) and oxidized (GSSG)) in isolated lens adhering epithelial cells (lens capsule) and fiber cells consisting the lens cortex and nucleus (lens core). In ARPE-19 cultures, ASSNAC (0.2 mM; 24 h) increased glutathione level by 2–2.5-fold with significantly higher increase in GSH compared to NAC treated cultures. Similarly, ex-vivo exposure of lenses to ASSNAC (1 mM) significantly reduced the GSSG level and prevented H2O2 (0.5 mM)-induced lens opacification. These results demonstrate that ASSNAC up-regulates glutathione level in RPE cells and protects them from oxidative stress-induced cell death as well as protects lenses from oxidative stress-induced opacity. Further validation of these results in animal models may suggest a potential use for ASSNAC as a protective therapy in retinal degenerative diseases as well as in attenuation of oxidative stress-induced lens opacity.
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Affiliation(s)
- Naphtali Savion
- Goldschleger Eye Research Institute and Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv 61390, Israel.
| | - Samia Dahamshi
- Goldschleger Eye Research Institute and Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv 61390, Israel.
| | - Milana Morein
- Goldschleger Eye Research Institute and Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv 61390, Israel.
| | - Shlomo Kotev-Emeth
- Goldschleger Eye Research Institute and Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv 61390, Israel.
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14
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Pick E. Using Synthetic Peptides for Exploring Protein-Protein Interactions in the Assembly of the NADPH Oxidase Complex. Methods Mol Biol 2019; 1982:377-415. [PMID: 31172485 DOI: 10.1007/978-1-4939-9424-3_23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The NADPH oxidase complex, responsible for reactive oxygen species (ROS) generation by phagocytes, consists of a membrane-associated flavocytochrome b 558 (a heterodimer of NOX2 and p22phox) and the cytosolic components p47phox, p67phox, Rac(1 or 2), and p40phox. NOX2 carries all redox stations through which electrons flow from NADPH to molecular oxygen, to generate the primary ROS, superoxide. For the electron flow to start, a conformational change in NOX2 is required. The dominant hypothesis is that this change is the result of the interaction of NOX2 with one or more of the cytosolic components (NADPH oxidase assembly). At the most basic level, assembly is the sum of several protein-protein interactions among oxidase components. This chapter describes a reductionist approach to the identification of regions in oxidase components involved in assembly. This approach consists of "transforming" one component in an array of overlapping synthetic peptides and assessing binding to the peptides of another component, represented by a recombinant protein. The peptides are tagged with biotin, at the N- or C-terminus, and immobilized on streptavidin-coated 96-well plates. The protein partners are expressed with a 6His tag and added to the plates in the fluid phase. Binding of the protein to the peptides is quantified by a kinetic ELISA , using a peroxidase-conjugated anti-polyhistidine antibody. Protein-peptide binding assays were applied successfully to (a) identifying the binding site on one component (represented by peptides) for another component (proteins), (b) precisely defining the "binding sequence," (c) acquiring information on the binding site in the partner protein, (d) investigating the effect of conformational changes in proteins on binding to peptides, (e) determining the effect of physicochemical modification of peptides on binding of proteins, and (f) identifying epitopes recognized by anti-oxidase component antibodies by binding of antibody to peptide arrays derived from the component.
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Affiliation(s)
- Edgar Pick
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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15
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Hjörleifsson JG, Ásgeirsson B. Chloride promotes refolding of active Vibrio alkaline phosphatase through an inactive dimeric intermediate with an altered interface. FEBS Open Bio 2018; 9:169-184. [PMID: 30652084 PMCID: PMC6325577 DOI: 10.1002/2211-5463.12565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/15/2022] Open
Abstract
Most enzymes are homodimers or higher order multimers. Cold‐active alkaline phosphatase from Vibrio splendidus (VAP) transitions into a dimer with very low activity under mild denaturation conditions. The desire to understand why this dimer fails to efficiently catalyse phosphomonoester hydrolysis led us to investigate interfacial communication between subunits. Here, we studied in detail the unfolding mechanism at two pH values and in the presence or absence of sodium chloride. At pH 8.0, the denaturation model had to include an inactive dimer intermediate and follow the pathway: N2 → I2 → 2U. At pH 10.5, the model was of a two‐state nature. Enzyme activity was not recovered under several examined refolding conditions. However, in the presence of 0.5 m NaCl, the enzyme was nearly fully reactivated after urea treatment. Thermal inactivation experiments were biphasic where the inactivation could be detected using CD spectroscopy at 190–200 nm. By incorporating a bimane fluorescence probe at the dimer interface, we could monitor inactivation/denaturation at two distinct sites at the dimer interface. A change in bimane fluorescence at both sites was observed during inactivation, but prior to the global unfolding event. Furthermore, the rate of change in bimane fluorescence correlated with inactivation rates at 40 °C. These results indicate and support the hypothesis that the subunits of VAP are only functional in the dimeric state due to the cooperative nature of the reaction mechanism when proper crosstalk between subunits is facilitated.
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Affiliation(s)
| | - Bjarni Ásgeirsson
- Department of Biochemistry, Science Institute University of Iceland Reykjavik Iceland
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16
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Bravo-Veyrat S, Hopfgartner G. High-throughput liquid chromatography differential mobility spectrometry mass spectrometry for bioanalysis: determination of reduced and oxidized form of glutathione in human blood. Anal Bioanal Chem 2018; 410:7153-7161. [DOI: 10.1007/s00216-018-1318-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 08/06/2018] [Accepted: 08/10/2018] [Indexed: 12/15/2022]
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17
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Fradin T, Bechor E, Berdichevsky Y, Dahan I, Pick E. Binding of p67phoxto Nox2 is stabilized by disulfide bonds between cysteines in the369Cys-Gly-Cys371triad in Nox2 and in p67phox. J Leukoc Biol 2018; 104:1023-1039. [DOI: 10.1002/jlb.4a0418-173r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 06/09/2018] [Accepted: 06/23/2018] [Indexed: 01/05/2023] Open
Affiliation(s)
- Tanya Fradin
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology; Sackler School of Medicine, Tel Aviv University; Tel Aviv Israel
| | - Edna Bechor
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology; Sackler School of Medicine, Tel Aviv University; Tel Aviv Israel
| | - Yevgeny Berdichevsky
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology; Sackler School of Medicine, Tel Aviv University; Tel Aviv Israel
| | - Iris Dahan
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology; Sackler School of Medicine, Tel Aviv University; Tel Aviv Israel
| | - Edgar Pick
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology; Sackler School of Medicine, Tel Aviv University; Tel Aviv Israel
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18
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Gordillo GM, Biswas A, Khanna S, Spieldenner JM, Pan X, Sen CK. Multidrug Resistance-associated Protein-1 (MRP-1)-dependent Glutathione Disulfide (GSSG) Efflux as a Critical Survival Factor for Oxidant-enriched Tumorigenic Endothelial Cells. J Biol Chem 2016; 291:10089-103. [PMID: 26961872 DOI: 10.1074/jbc.m115.688879] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/28/2022] Open
Abstract
Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics.
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Affiliation(s)
- Gayle M Gordillo
- From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and
| | - Ayan Biswas
- From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and
| | - Savita Khanna
- Davis Heart and Lung Research Institute, and Department of Surgery
| | | | - Xueliang Pan
- Center for Biostatistics, Ohio State University Wexner Medical Center, Columbus, Ohio 43212
| | - Chandan K Sen
- Davis Heart and Lung Research Institute, and Department of Surgery
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19
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Ruan Q, Chen Y, Kong X, Hua Y. Analysis using fluorescence labeling and mass spectrometry of disulfide-mediated interactions of soy protein when heated. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:3524-3533. [PMID: 25715170 DOI: 10.1021/jf504519z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
It is well-known that disulfide-mediated interactions are important when soy protein is heated, in which soy proteins are dissociated and rearranged to some new forms. In this study, the disulfide bond (SS) linked polymer, which was composed of the acidic (A) polypeptides of glycinin, basic (B) polypeptides of glycinin, and a small amount of α' and α of β-conglycinin, was formed as the major product, accompanied by the formation of SS-linked dimer of B and monomer of A as minor products. The role of sulfhydryl (SH) of different subunits/polypeptides for forming intermolecular SS was investigated. The SH of B in glycinin (Cys298 of G1, Cys289 of G2, Cys440 of G4) was transformed into SS in polymer identified by mass spectrometry analysis. The SH content of polymer was lower than that of glycinin and β-conglycinin subunits when heated. The SH content of B in polymer was lower than that in glycinin subunit, and both of them were decreased by heating. The SH content of A in polymer was increased and higher than that of B in polymer and A in glycinin subunit when heated. These results indicated that the SH of B in glycinin subunit was subjected to not only SH oxidation but also SH-SS exchange (with SS of A) for forming intermolecular SS of polymer. The SH oxidation and SH-SS exchange were proven by the change of SH content for the first time. The SH of B was suggested to be reactive for forming intermolecular SS of polymer.
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Affiliation(s)
- Qijun Ruan
- State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, People's Republic of China
| | - Yeming Chen
- State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, People's Republic of China
| | - Xiangzhen Kong
- State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, People's Republic of China
| | - Yufei Hua
- State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, People's Republic of China
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20
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Bechor E, Dahan I, Fradin T, Berdichevsky Y, Zahavi A, Federman Gross A, Rafalowski M, Pick E. The dehydrogenase region of the NADPH oxidase component Nox2 acts as a protein disulfide isomerase (PDI) resembling PDIA3 with a role in the binding of the activator protein p67 (phox.). Front Chem 2015; 3:3. [PMID: 25699251 PMCID: PMC4316792 DOI: 10.3389/fchem.2015.00003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 01/09/2015] [Indexed: 11/28/2022] Open
Abstract
The superoxide (O(·-) 2)-generating NADPH oxidase of phagocytes consists of a membrane component, cytochrome b 558 (a heterodimer of Nox2 and p22 (phox) ), and four cytosolic components, p47 (phox) , p67 (phox) , p40 (phox) , and Rac. The catalytic component, responsible for O(·-) 2 generation, is Nox2. It is activated by the interaction of the dehydrogenase region (DHR) of Nox2 with the cytosolic components, principally with p67 (phox) . Using a peptide-protein binding assay, we found that Nox2 peptides containing a (369)CysGlyCys(371) triad (CGC) bound p67 (phox) with high affinity, dependent upon the establishment of a disulfide bond between the two cysteines. Serially truncated recombinant Nox2 DHR proteins bound p67 (phox) only when they comprised the CGC triad. CGC resembles the catalytic motif (CGHC) of protein disulfide isomerases (PDIs). This led to the hypothesis that Nox2 establishes disulfide bonds with p67 (phox) via a thiol-dilsulfide exchange reaction and, thus, functions as a PDI. Evidence for this was provided by the following: (1) Recombinant Nox2 protein, which contained the CGC triad, exhibited PDI-like disulfide reductase activity; (2) Truncation of Nox2 C-terminal to the CGC triad or mutating C369 and C371 to R, resulted in loss of PDI activity; (3) Comparison of the sequence of the DHR of Nox2 with PDI family members revealed three small regions of homology with PDIA3; (4) Two monoclonal anti-Nox2 antibodies, with epitopes corresponding to regions of Nox2/PDIA3 homology, reacted with PDIA3 but not with PDIA1; (5) A polyclonal anti-PDIA3 (but not an anti-PDIA1) antibody reacted with Nox2; (6) p67 (phox) , in which all cysteines were mutated to serines, lost its ability to bind to a Nox2 peptide containing the CGC triad and had an impaired capacity to support oxidase activity in vitro. We propose a model of oxidase assembly in which binding of p67 (phox) to Nox2 via disulfide bonds, by virtue of the intrinsic PDI activity of Nox2, stabilizes the primary interaction between the two components.
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Affiliation(s)
| | | | | | | | | | | | | | - Edgar Pick
- The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv UniversityTel Aviv, Israel
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21
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Total cysteine and glutathione determination in hemolymph of individual adult D. melanogaster. Anal Chim Acta 2014; 853:660-667. [PMID: 25467515 DOI: 10.1016/j.aca.2014.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/28/2014] [Accepted: 10/02/2014] [Indexed: 11/22/2022]
Abstract
Determination of thiols, glutathione (GSH) and cysteine (Cys) are important due to their roles in oxidative stress and aging. Oxidants such as soluble O2 and H2O2 promote oxidation of thiols to disulfide (SS) bonded dimers affecting quantitation accuracy. The method presented here reduces disulfide-bonded species followed by fluorescence labelling of the 29.5 (±18.2) nL hemolymph volumes of individual adult Drosophila Melanogaster. The availability of only tens of nanoliter (nL) samples that are also highly volume variant requires efficient sample handling to improve thiol measurements while minimizing sample dilution. The optimized method presented here utilizes defined lengths of capillaries to meter tris(2-carboxyethyl)phosphine reducing reagent and monobromobimane derivatizing reagent volumes enabling Cys and GSH quantitation with only 20-fold dilution. The nL assay developed here was optimized with respect to reagent concentrations, sample dilution, reaction times and temperatures. Separation and identification of the nL thiol mixtures were obtained with capillary electrophoresis-laser induced fluorescence. To demonstrate the capability of this method total Cys and total GSH were measured in the hemolymph collected from individual adult D. Melanogaster. The thiol measurements were used to compare a mutant fly strain with a non-functional cystine-glutamate transporter (xCT) to its background control. The mutant fly, genderblind (gb), carries a non-functional gene for a protein similar to mammalian xCT whose function is not fully understood. Average concentrations obtained for mutant and control flies are 2.19 (±0.22) and 1.94 (±0.34) mM Cys and 2.14 (±0.60) and 2.08 (±0.71) mM GSH, respectively, and are not significantly different (p>0.05). Statistical analysis showed significant differences in total GSH of males and females independent of the xCT mutation. Overall, the method demonstrates an approach for effective chemical characterization of thiols in nL sample volumes.
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Portillo-Ledesma S, Sardi F, Manta B, Tourn MV, Clippe A, Knoops B, Alvarez B, Coitiño EL, Ferrer-Sueta G. Deconstructing the Catalytic Efficiency of Peroxiredoxin-5 Peroxidatic Cysteine. Biochemistry 2014; 53:6113-25. [DOI: 10.1021/bi500389m] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Florencia Sardi
- Laboratory
Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Bruno Manta
- Laboratory
Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | | | - André Clippe
- Laboratory
of Cell Biology, Institut des Sciences de la Vie, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Bernard Knoops
- Laboratory
of Cell Biology, Institut des Sciences de la Vie, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Beatriz Alvarez
- Center for
Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
| | | | - Gerardo Ferrer-Sueta
- Center for
Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
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23
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Montoya L, Pluth MD. Hydrogen sulfide deactivates common nitrobenzofurazan-based fluorescent thiol labeling reagents. Anal Chem 2014; 86:6032-9. [PMID: 24852143 PMCID: PMC4063329 DOI: 10.1021/ac501193r] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/23/2014] [Indexed: 02/08/2023]
Abstract
Sulfhydryl-containing compounds, including thiols and hydrogen sulfide (H2S), play important but differential roles in biological structure and function. One major challenge in separating the biological roles of thiols and H2S is developing tools to effectively separate the reactivity of these sulfhydryl-containing compounds. To address this challenge, we report the differential responses of common electrophilic fluorescent thiol labeling reagents, including nitrobenzofurazan-based scaffolds, maleimides, alkylating agents, and electrophilic aldehydes, toward cysteine and H2S. Although H2S reacted with all of the investigated scaffolds, the photophysical response to each scaffold was significantly different. Maleimide-based, alkylating, and aldehydic thiol labeling reagents provided a diminished fluorescence response when treated with H2S. By contrast, nitrobenzofurazan-based labeling reagents were deactivated by H2S addition. Furthermore, the addition of H2S to thiol-activated nitrobenzofurazan-based reagents reduced the fluorescence signal, thus establishing the incompatibility of nitrobenzofurazan-based thiol labeling reagents in the presence of H2S. Taken together, these studies highlight the differential reactivity of thiols and H2S toward common thiol-labeling reagents and suggest that sufficient care must be taken when labeling or measuring thiols in cellular environments that produce H2S due to the potential for both false-positive and eroded responses.
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Affiliation(s)
- Leticia
A. Montoya
- Department
of Chemistry and
Biochemistry, Institute of Molecular Biology, Materials Science Institute, 1253
University of Oregon, Eugene, Oregon 97403, United States
| | - Michael D. Pluth
- Department
of Chemistry and
Biochemistry, Institute of Molecular Biology, Materials Science Institute, 1253
University of Oregon, Eugene, Oregon 97403, United States
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24
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Li J, O W, Li W, Jiang ZG, Ghanbari HA. Oxidative stress and neurodegenerative disorders. Int J Mol Sci 2013; 14:24438-75. [PMID: 24351827 PMCID: PMC3876121 DOI: 10.3390/ijms141224438] [Citation(s) in RCA: 290] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/27/2013] [Accepted: 12/06/2013] [Indexed: 12/14/2022] Open
Abstract
Living cells continually generate reactive oxygen species (ROS) through the respiratory chain during energetic metabolism. ROS at low or moderate concentration can play important physiological roles. However, an excessive amount of ROS under oxidative stress would be extremely deleterious. The central nervous system (CNS) is particularly vulnerable to oxidative stress due to its high oxygen consumption, weakly antioxidative systems and the terminal-differentiation characteristic of neurons. Thus, oxidative stress elicits various neurodegenerative diseases. In addition, chemotherapy could result in severe side effects on the CNS and peripheral nervous system (PNS) of cancer patients, and a growing body of evidence demonstrates the involvement of ROS in drug-induced neurotoxicities as well. Therefore, development of antioxidants as neuroprotective drugs is a potentially beneficial strategy for clinical therapy. In this review, we summarize the source, balance maintenance and physiologic functions of ROS, oxidative stress and its toxic mechanisms underlying a number of neurodegenerative diseases, and the possible involvement of ROS in chemotherapy-induced toxicity to the CNS and PNS. We ultimately assess the value for antioxidants as neuroprotective drugs and provide our comments on the unmet needs.
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Affiliation(s)
- Jie Li
- Department of Geratology, First Hospital of Jilin University, Changchun, Jilin 130021, China; E-Mail:
| | - Wuliji O
- College of Pharmacology, Inner Mongolia University for the Nationalities, Tongliao, Inner Mongolia 028000, China; E-Mail:
| | - Wei Li
- Cancer Center, First Hospital of Jilin University, Changchun, Jilin 130021, China; E-Mail:
| | - Zhi-Gang Jiang
- Panacea Pharmaceuticals, Inc., Gaithersburg, MD 20877, USA; E-Mail:
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25
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Ruan Q, Chen Y, Kong X, Hua Y. Comparative studies on sulfhydryl determination of soy protein using two aromatic disulfide reagents and two fluorescent reagents. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:2661-2668. [PMID: 23432329 DOI: 10.1021/jf303005y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this study, the sulfhydryl (SH) contents of unheated and heated (90 °C, 5 min) soy protein were detected under different conditions (pH, reagent addition order, SDS/GuHCl concentration, EDTA) using two aromatic disulfide reagents: 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and 4,4'-dithiodipyridine (DPS). Two fluorescent alkylating reagents, monobromobimane (mBBr) and N-(1-pyrenyl)maleimide (NPM), were chosen due to their high sensitivity and were also used. Amino acid analysis was used to detect the SH (cysteine) contents of unheated (7.51 ± 0.45 μmol SH/g protein) and heated (1.47 ± 0.10 μmol SH/g protein) soy protein, and similar results were obtained using enzymatic hydrolysis-assisted DPS. The SH content detected by DTNB was affected by pH, denaturant species, and denaturant concentration, and the best results were obtained at pH 7.0 when 6 M GuHCl was added after DTNB. These results were lower than that of the amino acid analysis, however. The SH detected by DPS was not as affected as that of DTNB by pH, denaturant species, and denaturant concentration. Additionally, the results of the amino acid analysis were similar to that of DPS at pH 7.0 in 2% SDS and 4-6 M GuHCl when SDS and GuHCl were added after DPS. EDTA did not have a significant effect on SH detection when DTNB and DPS were added before SDS and GuHCl. Finally, although mBBr and NPM can detect SH in low protein concentrations ((1)/10 of that required for DTNB and DPS), mBBr and NPM overestimated the SH content of soy protein. Therefore, using DPS at pH 7.0 when it is added before SDS and GuHCl is the most reliable method for detecting the SH content of soy protein.
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Affiliation(s)
- Qijun Ruan
- State Key Laboratory of Food Science and Technology and School of Food Science and Technology, Jiangnan University , 1800 Lihu Avenue, Wuxi 214122, Jiangsu Province, People's Republic of China
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26
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Sardi F, Manta B, Portillo-Ledesma S, Knoops B, Comini MA, Ferrer-Sueta G. Determination of acidity and nucleophilicity in thiols by reaction with monobromobimane and fluorescence detection. Anal Biochem 2013; 435:74-82. [PMID: 23296042 DOI: 10.1016/j.ab.2012.12.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/10/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022]
Abstract
A method based on the differential reactivity of thiol and thiolate with monobromobimane (mBBr) has been developed to measure nucleophilicity and acidity of protein and low-molecular-weight thiols. Nucleophilicity of the thiolate is measured as the pH-independent second-order rate constant of its reaction with mBBr. The ionization constants of the thiols are obtained through the pH dependence of either second-order rate constant or initial rate of reaction. For readily available thiols, the apparent second-order rate constant is measured at different pHs and then plotted and fitted to an appropriate pH function describing the observed number of ionization equilibria. For less available thiols, such as protein thiols, the initial rate of reaction is determined in a wide range of pHs and fitted to the appropriate pH function. The method presented here shows excellent sensitivity, allowing the use of nanomolar concentrations of reagents. The method is suitable for scaling and high-throughput screening. Example determinations of nucleophilicity and pK(a) are presented for captopril and cysteine as low-molecular-weight thiols and for human peroxiredoxin 5 and Trypanosoma brucei monothiol glutaredoxin 1 as protein thiols.
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Affiliation(s)
- Florencia Sardi
- Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
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27
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Cappiello M, Peroni E, Lepore A, Moschini R, Del Corso A, Balestri F, Mura U. Rapid colorimetric determination of reduced and oxidized glutathione using an end point coupled enzymatic assay. Anal Bioanal Chem 2012. [DOI: 10.1007/s00216-012-6577-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Joe-Wong C, Shoenfelt E, Hauser EJ, Crompton N, Myneni SCB. Estimation of reactive thiol concentrations in dissolved organic matter and bacterial cell membranes in aquatic systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:9854-61. [PMID: 22916681 DOI: 10.1021/es301381n] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Organic thiols are highly reactive ligands and play an important role in the speciation of several metals and organic pollutants in the environment. Although small thiols can be isolated and their concentrations can be estimated using chromatographic and derivatization techniques, estimating concentrations of thiols associated with biomacromolecules and humic substances has been difficult. Here we present a fluorescence-spectroscopy-based method for estimating thiol concentrations in biomacromolecules and cell membranes using one of the soluble bromobimanes, monobromo(trimethylammonio)bimane (qBBr). The fluorescence of this molecule increases significantly when it binds to a thiol. The change in the sample fluorescence due to thiols reacting with qBBr is used to determine thiol concentration in a sample. Using this method, small thiols such as cysteine and glutathione can be detected in clean solutions down to ~50 nM without their separation and prior concentration. Thiols associated with dissolved organic matter (DOM) can be detected down to low micromolar concentration, depending on the DOM background fluorescence. The charge on qBBr prevents its rapid diffusion across cell membranes, so qBBr is ideal for estimating thiol concentration at the cell membrane-water interface. This method was successfully used to determine the thiol concentration on the cell envelope of intact Bacillus subtilis to nanomolar concentration without any special sample preparation. Among the chemical species tested for potential interferences (other reduced sulfides methionine and cystine, carboxylate, salt (MgCl(2))), carboxylates significantly influenced the absolute fluorescence signal of the thiol-qBBr complex. However, this does not affect the detection of thiols in heterogeneous mixtures using the presented method.
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Affiliation(s)
- Claresta Joe-Wong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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29
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Vasicek L, O'Brien JP, Browning KS, Tao Z, Liu HW, Brodbelt JS. Mapping protein surface accessibility via an electron transfer dissociation selectively cleavable hydrazone probe. Mol Cell Proteomics 2012; 11:O111.015826. [PMID: 22393264 DOI: 10.1074/mcp.o111.015826] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A protein's surface influences its role in protein-protein interactions and protein-ligand binding. Mass spectrometry can be used to give low resolution structural information about protein surfaces and conformations when used in combination with derivatization methods that target surface accessible amino acid residues. However, pinpointing the resulting modified peptides upon enzymatic digestion of the surface-modified protein is challenging because of the complexity of the peptide mixture and low abundance of modified peptides. Here a novel hydrazone reagent (NN) is presented that allows facile identification of all modified surface residues through a preferential cleavage upon activation by electron transfer dissociation coupled with a collision activation scan to pinpoint the modified residue in the peptide sequence. Using this approach, the correlation between percent reactivity and surface accessibility is demonstrated for two biologically active proteins, wheat eIF4E and PARP-1 Domain C.
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Affiliation(s)
- Lisa Vasicek
- Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA
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30
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Kim SG, Chung JS, Sutton RB, Lee JS, López-Maury L, Lee SY, Florencio FJ, Lin T, Zabet-Moghaddam M, Wood MJ, Nayak K, Madem V, Tripathy JN, Kim SK, Knaff DB. Redox, mutagenic and structural studies of the glutaredoxin/arsenate reductase couple from the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1824:392-403. [PMID: 22155275 DOI: 10.1016/j.bbapap.2011.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/12/2011] [Accepted: 10/17/2011] [Indexed: 10/15/2022]
Abstract
The arsenate reductase from the cyanobacterium Synechocystis sp. PCC 6803 has been characterized in terms of the redox properties of its cysteine residues and their role in the reaction catalyzed by the enzyme. Of the five cysteines present in the enzyme, two (Cys13 and Cys35) have been shown not to be required for catalysis, while Cys8, Cys80 and Cys82 have been shown to be essential. The as-isolated enzyme contains a single disulfide, formed between Cys80 and Cys82, with an oxidation-reduction midpoint potential (E(m)) value of -165mV at pH 7.0. It has been shown that Cys15 is the only one of the four cysteines present in Synechocystis sp. PCC 6803 glutaredoxin A required for its ability to serve as an electron donor to arsenate reductase, while the other three cysteines (Cys18, Cys36 and Cys70) play no role. Glutaredoxin A has been shown to contain a single redox-active disulfide/dithiol couple, with a two-electron, E(m) value of -220mV at pH 7.0. One cysteine in this disulfide/dithiol couple has been shown to undergo glutathionylation. An X-ray crystal structure, at 1.8Å resolution, has been obtained for glutaredoxin A. The probable orientations of arsenate reductase disulfide bonds present in the resting enzyme and in a likely reaction intermediate of the enzyme have been examined by in silico modeling, as has the surface environment of arsenate reductase in the vicinity of Cys8, the likely site for the initial reaction between arsenate and the enzyme.
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Affiliation(s)
- Sang Gon Kim
- Department of Chemistry and Biochemistry and the Institute of Biomedical Studies, Baylor University, Waco, TX 76798-7348, USA
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31
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Yoshida S, Hong S, Suzuki T, Nada S, Mannan AM, Wang J, Okada M, Guan KL, Inoki K. Redox regulates mammalian target of rapamycin complex 1 (mTORC1) activity by modulating the TSC1/TSC2-Rheb GTPase pathway. J Biol Chem 2011; 286:32651-60. [PMID: 21784859 PMCID: PMC3173157 DOI: 10.1074/jbc.m111.238014] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is a kinase that plays a key role in a wide array of cellular processes and exists in two distinct functional complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Although mTORC2 is primarily activated by growth factors, mTORC1 is regulated by numerous extracellular and intracellular signals such as nutrients, growth factors, and cellular redox. Previous study has shown that cysteine oxidants sufficiently activate mTORC1 activity under amino acid-depleted conditions and that a reducing agent effectively suppresses amino acid-induced mTORC1 activity, thereby raising the possibility that redox-sensitive mechanisms underlie amino acid-dependent mTORC1 regulation. However, the molecular mechanism by which redox regulates mTORC1 activity is not well understood. In this study, we show that the redox-sensitive regulation of mTORC1 occurs via Rheb but not the Rag small GTPase. Enhancing cellular redox potential with cysteine oxidants significantly increases Rheb GTP levels. Importantly, modulation of the cellular redox potential with a cysteine oxidant or reducing agent failed to alter mTORC1 activity in TSC1(-/-) or TSC2(-/-) mouse embryonic fibroblast cells. Furthermore, a cysteine oxidant has little effect on mTOR localization but sufficiently activates mTORC1 activity in both p18(-/-) and control mouse embryonic fibroblast cells, suggesting that the redox-sensitive regulation of mTORC1 occurs independent of the Ragulator·Rag complex. Taken together, our results suggest that the TSC complex plays an important role in redox-sensitive mTORC1 regulation and argues for the activation of mTORC1 in places other than the lysosome upon inhibition of the TSC complex.
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Affiliation(s)
| | | | | | - Shigeyuki Nada
- the Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan, and
| | | | | | - Masato Okada
- the Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan, and
| | - Kun-Liang Guan
- the Department of Pharmacology, Moores Cancer Center, University of California, San Diego, La Jolla, California 92093-0815
| | - Ken Inoki
- From the Life Sciences Institute and ,Departments of Molecular and Integrative Physiology and ,Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, , To whom correspondence should be addressed: 210 Washtenaw Ave., Ann Arbor, MI 48109-2216. Fax: 734-647-9702; E-mail:
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Lindahl M, Mata-Cabana A, Kieselbach T. The disulfide proteome and other reactive cysteine proteomes: analysis and functional significance. Antioxid Redox Signal 2011; 14:2581-642. [PMID: 21275844 DOI: 10.1089/ars.2010.3551] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Ten years ago, proteomics techniques designed for large-scale investigations of redox-sensitive proteins started to emerge. The proteomes, defined as sets of proteins containing reactive cysteines that undergo oxidative post-translational modifications, have had a particular impact on research concerning the redox regulation of cellular processes. These proteomes, which are hereafter termed "disulfide proteomes," have been studied in nearly all kingdoms of life, including animals, plants, fungi, and bacteria. Disulfide proteomics has been applied to the identification of proteins modified by reactive oxygen and nitrogen species under stress conditions. Other studies involving disulfide proteomics have addressed the functions of thioredoxins and glutaredoxins. Hence, there is a steadily growing number of proteins containing reactive cysteines, which are probable targets for redox regulation. The disulfide proteomes have provided evidence that entire pathways, such as glycolysis, the tricarboxylic acid cycle, and the Calvin-Benson cycle, are controlled by mechanisms involving changes in the cysteine redox state of each enzyme implicated. Synthesis and degradation of proteins are processes highly represented in disulfide proteomes and additional biochemical data have established some mechanisms for their redox regulation. Thus, combined with biochemistry and genetics, disulfide proteomics has a significant potential to contribute to new discoveries on redox regulation and signaling.
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Affiliation(s)
- Marika Lindahl
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Centro de Investigaciones Científicas Isla de la Cartuja, Seville, Spain
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Izigov N, Farzam N, Savion N. S-allylmercapto-N-acetylcysteine up-regulates cellular glutathione and protects vascular endothelial cells from oxidative stress. Free Radic Biol Med 2011; 50:1131-9. [PMID: 21281712 DOI: 10.1016/j.freeradbiomed.2011.01.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/10/2011] [Accepted: 01/21/2011] [Indexed: 10/18/2022]
Abstract
Oxidative stress and/or low cellular glutathione (GSH) levels are associated with the development and progression of numerous pathological conditions. Cells possess various antioxidant protection mechanisms, including GSH and phase II detoxifying enzymes. N-acetylcysteine (NAC) supplies cells with cysteine to increase GSH level but its efficacy is relatively low because of its limited tissue penetration. Allicin (diallyl thiosulfinate), a reactive sulfaorganic compound, increases cellular GSH and phase II detoxifying enzymes in vascular endothelial cells (EC). A novel compound was designed: S-allylmercapto-N-acetylcysteine (ASSNAC), a conjugate of S-allyl mercaptan (a component of allicin) and NAC. Both ASSNAC and NAC increased cellular GSH of ECs, reaching a maximum of up to four- and threefold increase after exposure for 24 or 6 h at a concentration of 0.2 or 1 mM, respectively. ASSNAC induced nuclear translocation of the activated transcription factor Nrf2 and expression of phase II detoxifying enzymes. EC exposure to tBuOOH resulted in 75% cytotoxicity, and pretreatment of cultures with 0.2 mM ASSNAC or 2mM NAC reduced cytotoxicity to 20 and 42%, respectively. In conclusion, ASSNAC is superior to NAC in protecting cells from oxidative stress because of its ability to up-regulate both GSH and the expression of phase II detoxifying enzymes.
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Affiliation(s)
- Nira Izigov
- Goldschleger Eye Research Institute, Tel Hashomer 52621, Israel
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34
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Shankar BS, Pandey R, Amin P, Misra HS, Sainis KB. Role of glutathione in augmenting the anticancer activity of pyrroloquinoline quinone (PQQ). Redox Rep 2010; 15:146-54. [PMID: 20663290 DOI: 10.1179/174329210x12650506623762] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Pyrroloquinoline quinone (PQQ), a bacterial redox co-factor and antioxidant, is highly reactive with nucleophilic compounds present in biological fluids. PQQ induced apoptosis in human promonocytic leukemia U937 cells and this was accompanied by depletion of the major cellular antioxidant glutathione and increase in intracellular reactive oxygen species (ROS). Treatment with glutathione (GSH) or N-acetyl-L-cysteine (NAC) did not spare PQQ toxicity but resulted in a 2-5-fold increase in PQQ-induced apoptosis in U937 cells. Cellular GSH levels increased following treatment by NAC alone but were severely depleted by co-treatment with NAC and PQQ. This was accompanied by an increase in intracellular ROS. Alternatively, depletion of glutathione also resulted in increased PQQ cytotoxicity. However, the cells underwent necrosis as evidenced by dual labeling with annexin V and propidium iodide. PQQ-induced cytotoxicity is thus critically regulated by the cellular redox status. An increase in GSH can augment apoptosis and its depletion can switch the mode of cell death to necrosis in the presence of PQQ. Our data suggest that modulation of intracellular GSH can be used as an effective strategy to potentiate cytotoxicity of quinones like PQQ.
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Affiliation(s)
- Bhavani S Shankar
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
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35
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Frassa MV, Ceolín M, Dreon MS, Heras H. Structure and stability of the neurotoxin PV2 from the eggs of the apple snail Pomacea canaliculata. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1492-9. [PMID: 20215051 DOI: 10.1016/j.bbapap.2010.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2009] [Revised: 02/01/2010] [Accepted: 02/24/2010] [Indexed: 10/19/2022]
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36
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Response of the oxygen sensor NreB to air in vivo: Fe-S-containing NreB and apo-NreB in aerobically and anaerobically growing Staphylococcus carnosus. J Bacteriol 2010; 192:86-93. [PMID: 19854899 DOI: 10.1128/jb.01248-09] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The sensor kinase NreB from Staphylococcus carnosus contains an O(2)-sensitive [4Fe-4S](2+) cluster which is converted by O(2) to a [2Fe-2S](2+) cluster, followed by complete degradation and formation of Fe-S-less apo-NreB. NreB.[2Fe-2S](2+) and apoNreB are devoid of kinase activity. NreB contains four Cys residues which ligate the Fe-S clusters. The accessibility of the Cys residues to alkylating agents was tested and used to differentiate Fe-S-containing and Fe-S-less NreB. In a two-step labeling procedure, accessible Cys residues in the native protein were first labeled by iodoacetate. In the second step, Cys residues not labeled in the first step were alkylated with the fluorescent monobromobimane (mBBr) after denaturing of the protein. In purified (aerobic) apoNreB, most (96%) of the Cys residues were alkylated in the first step, but in anaerobic (Fe-S-containing) NreB only a small portion (23%) were alkylated. In anaerobic bacteria, a very small portion of the Cys residues of NreB (9%) were accessible to alkylation in the native state, whereas most (89%) of the Cys residues from aerobic bacteria were accessible. The change in accessibility allowed determination of the half-time (6 min) for the conversion of NreB x [4Fe-4S](2+) to apoNreB after the addition of air in vitro. Overall, in anaerobic bacteria most of the NreB exists as NreB x [4Fe-4S](2+), whereas in aerobic bacteria the (Fe-S-less) apoNreB is predominant and represents the physiological form. The number of accessible Cys residues was also determined by iodoacetate alkylation followed by mass spectrometry of Cys-containing peptides. The pattern of mass increases confirmed the results from the two-step labeling experiments.
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Hansen RE, Winther JR. An introduction to methods for analyzing thiols and disulfides: Reactions, reagents, and practical considerations. Anal Biochem 2009; 394:147-58. [DOI: 10.1016/j.ab.2009.07.051] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 07/31/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022]
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Fluman N, Cohen-Karni D, Weiss T, Bibi E. A promiscuous conformational switch in the secondary multidrug transporter MdfA. J Biol Chem 2009; 284:32296-304. [PMID: 19808670 DOI: 10.1074/jbc.m109.050658] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Multidrug (Mdr) transporters are membrane proteins that actively export structurally dissimilar drugs from the cell, thereby rendering the cell resistant to toxic compounds. Similar to substrate-specific transporters, Mdr transporters also undergo substrate-induced conformational changes. However, the mechanism by which a variety of dissimilar substrates are able to induce similar transport-compatible conformational responses in a single transporter remains unclear. To address this major aspect of Mdr transport, we studied the conformational behavior of the Escherichia coli Mdr transporter MdfA. Our results show that indeed, different substrates induce similar conformational changes in the transporter. Intriguingly, in addition, we observed that compounds other than substrates are able to confer similar conformational changes when covalently attached at the putative Mdr recognition pocket of MdfA. Taken together, the results suggest that the Mdr-binding pocket of MdfA is conformationally sensitive. We speculate that the same conformational switch that usually drives active transport is triggered promiscuously by merely occupying the Mdr-binding site.
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Affiliation(s)
- Nir Fluman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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Toyo’oka T. Recent advances in separation and detection methods for thiol compounds in biological samples. J Chromatogr B Analyt Technol Biomed Life Sci 2009; 877:3318-30. [DOI: 10.1016/j.jchromb.2009.03.034] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 03/19/2009] [Accepted: 03/23/2009] [Indexed: 11/28/2022]
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Abstract
Thiol alkylation is a powerful technique for the labeling of proteins. We report a new class of highly reactive, selective, and fluorogenic probes for thiols in aqueous solution at neutral pH, based on the 7-oxanorbornadiene (OND) framework. The maleate moiety in 7-oxabicyclo[2.2.1]hept-2,5-diene-2,3-dicarboxylic acid esters serves as both a tunable electrophile and an intramolecular quencher of an attached dansyl fluorophore. Thiols have been found to add with high rates (second-order rate constants of 40-200 M(-1) s(-1)) to give adducts that exhibit enhancements of fluorescence intensity up to 180-fold. The resulting adducts are also versatile with respect to cleavage (release) reactions by two mechanisms. First, retro-Diels-Alder fragmentation occurs with half-lives from days to weeks at room temperature, and an epoxide derivative is also reported that is incapable of cycloreversion cleavage. Second, monoamide OND derivatives undergo rapid closure to succinimides upon thiol addition, providing a thiol-triggered mechanism for immediate alcohol release. Peptides and proteins containing free thiol groups were labeled with OND electrophiles with high chemoselectivity. Since the system is so easily assembled from readily accessible modules, various functional groups can be added to OND linkers to allow the attachment of other molecules of interest.
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Affiliation(s)
- Vu Hong
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - Alexander Kislukhin
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
| | - M.G. Finn
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037
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Müller MQ, de Koning LJ, Schmidt A, Ihling C, Syha Y, Rau O, Mechtler K, Schubert-Zsilavecz M, Sinz A. An Innovative Method To Study Target Protein−Drug Interactions by Mass Spectrometry. J Med Chem 2009; 52:2875-9. [DOI: 10.1021/jm9000665] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mathias Q. Müller
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Leo J. de Koning
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Andreas Schmidt
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Christian Ihling
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Yvonne Syha
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Oliver Rau
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Karl Mechtler
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Manfred Schubert-Zsilavecz
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
| | - Andrea Sinz
- Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther-Universität Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle/Saale, Germany, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, NL-1018 WV Amsterdam, The Netherlands, Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, A-1030 Wien, Austria, and Department of Biochemistry, Chemistry and Pharmacy, Institute of Pharmaceutical Chemistry, Johann-Wolfgang
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Liu YD, Chen X, Enk JZV, Plant M, Dillon TM, Flynn GC. Human IgG2 antibody disulfide rearrangement in vivo. J Biol Chem 2008; 283:29266-72. [PMID: 18713741 PMCID: PMC2662016 DOI: 10.1074/jbc.m804787200] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 08/12/2008] [Indexed: 11/06/2022] Open
Abstract
Proteins destined to circulate in the blood are first folded and assembled in the endoplasmic reticulum of secretory cells. For antibodies, like many other serum proteins, the folding and assembly steps involve the formation of disulfide bonds. Such bonds have been thought to be static features of proteins, stabilizing domains, and linking polypeptide chains, although some cases of extracellular disulfide bond cleavage have been noted. Recently, the human IgG2 antibody subclass was found to possess multiple structures differing in specific disulfide linkages. These structures are naturally occurring and can, in some cases, affect the activity of the antibody. Here we show that these IgG2 disulfide linkages interconvert while circulating in humans. Secretory cells initially produce primarily one form (IgG2-A), which is rapidly converted to a second form (IgG2-A/B) while circulating in the blood, followed by a slower conversion to a third form (IgG2-B). This work demonstrates that the disulfide structure of the IgG2 antibody is dynamic in vivo, on a time scale similar to that of the protein's lifetime. Thus, changes to the IgG2 disulfide structure provide a marker of the protein's age and may alter its activity over its lifetime.
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Affiliation(s)
- Y Diana Liu
- Department of Analytical and Formulation Sciences, Amgen, Incorporated, Thousand Oaks, California 91320, USA
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43
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Lieberman I, Shemer G, Fried T, Kosower EM, Markovich G. Plasmon-resonance-enhanced absorption and circular dichroism. Angew Chem Int Ed Engl 2008; 47:4855-7. [PMID: 18496800 DOI: 10.1002/anie.200800231] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Itai Lieberman
- School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
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Selective and sensitive determination of lipoyllysine (protein-bound α-lipoic acid) in biological specimens by high-performance liquid chromatography with fluorescence detection. Anal Chim Acta 2008; 618:210-7. [DOI: 10.1016/j.aca.2008.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 04/30/2008] [Accepted: 05/01/2008] [Indexed: 11/21/2022]
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46
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Reduced apo-fumarate nitrate reductase regulator (apoFNR) as the major form of FNR in aerobically growing Escherichia coli. J Bacteriol 2007; 190:879-86. [PMID: 18055593 DOI: 10.1128/jb.01374-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Under anoxic conditions, the Escherichia coli oxygen sensor FNR (fumarate nitrate reductase regulator) is in the active state and contains a [4Fe-4S] cluster. Oxygen converts [4Fe-4S]FNR to inactive [2Fe-2S]FNR. After prolonged exposure to air in vitro, apoFNR lacking a Fe-S cluster is formed. ApoFNR can be differentiated from Fe-S-containing forms by the accessibility of the five Cys thiol residues, four of which serve as ligands for the Fe-S cluster. The presence of apoFNR in aerobically and anaerobically grown E. coli was analyzed in situ using thiol reagents. In anaerobically and aerobically grown cells, the membrane-permeable monobromobimane labeled one to two and four Cys residues, respectively; the same labeling pattern was found with impermeable thiol reagents after cell permeabilization. Alkylation of FNR in aerobic bacteria and counting the labeled residues by mass spectrometry showed a form of FNR with five accessible Cys residues, corresponding to apoFNR with all Cys residues in the thiol state. Therefore, aerobically growing cells contain apoFNR, whereas a significant amount of Fe-S-containing FNR was not detected under these conditions. Exposure of anaerobic bacteria to oxygen caused conversion of Fe-S-containing FNR to apoFNR within 6 min. ApoFNR from aerobic bacteria contained no disulfide, in contrast to apoFNR formed in vitro by air inactivation, and all Cys residues were in the thiol form.
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47
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Satoh S, Toyo'oka T, Fukushima T, Inagaki S. Simultaneous determination of α-lipoic acid and its reduced form by high-performance liquid chromatography with fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 854:109-15. [PMID: 17462965 DOI: 10.1016/j.jchromb.2007.04.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 03/16/2007] [Accepted: 04/03/2007] [Indexed: 11/30/2022]
Abstract
The simultaneous determination of alpha-lipoic acid (LA) and DHLA (reduced form of LA) was carried out by HPLC with fluorescence detection. DHLA in the sample was first labeled with ABD-F at room temperature for 10 min and then the LA was labeled with SBD-F at 50 degrees C for 1 h after conversion to DHLA using the reducing agent, TCEP. The resulting fluorophores, ABD-DHLA and SBD-DHLA, were separated by reversed-phase chromatography and detected at 510 nm (excitation at 380 nm). Both fluorophors were completely separated without any interference of endogenous thiols and disulfides in the sample and sensitively detected by fluorimetry. The proposed method was applied to the assay of the LA supplement and the determination in human plasma after the oral administration of LA tablets. The concentration (%) of LA in the tablet was reasonable to the stated amount. Furthermore, the result of a time course study in the plasma after the administration of LA did not differ from a previous report. Thus, the present method seems to be applicable to the simultaneous determination of LA and DHLA in various biological specimens.
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Affiliation(s)
- Soichiro Satoh
- Division of Bio-Analytical Chemistry, School of Pharmaceutical Sciences, and COE Program in the 21st Century, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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48
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Raththagala M, Root PD, Spence DM. Dynamic Monitoring of Glutathione in Erythrocytes, without a Separation Step, in the Presence of an Oxidant Insult. Anal Chem 2006; 78:8556-60. [PMID: 17165853 DOI: 10.1021/ac061163u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A method for the quantitative determination of the antioxidant form of glutathione (GSH) in red blood cells (RBCs) is described that does not require separation of the analyte of interest from the complex cellular matrix. The measurement portion of the analysis is performed using fluorescence spectrophotometry after monochlorobimane (a recognized probe for GSH) is added to a mixture containing RBCs and glutathione transferase (GST). This method was employed to determine the GSH concentration (0.042 +/- 0.002 mM) in a solution of 1% RBCs obtained from rabbits (n = 6). When spiked with authentic GSH (0.50 micromol), 99.8% of the GSH was recovered. Addition of GST to the sample mixture enabled most measurements to be made after 5-10 min of reaction time. Importantly, a decrease in GSH was measured upon the addition of a recognized oxidant (diamide) to the RBC sample followed by a subsequent return to normal levels of GSH. The ability of the GSH to recover from the oxidant attack occurred in a dose-dependent manner, requiring 30 and 90 min to recover from oxidant insults of 20 and 40 microM diamide, respectively. The antioxidant capabilities of the GSH were able to be monitored in real time, thus providing a method to dynamically monitor the ability of the RBC to maintain homeostasis in a complex matrix.
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Affiliation(s)
- Madushi Raththagala
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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49
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Sinz A. Chemical cross-linking and mass spectrometry to map three-dimensional protein structures and protein-protein interactions. MASS SPECTROMETRY REVIEWS 2006; 25:663-82. [PMID: 16477643 DOI: 10.1002/mas.20082] [Citation(s) in RCA: 514] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Closely related to studying the function of a protein is the analysis of its three-dimensional structure and the identification of interaction sites with its binding partners. An alternative approach to the high-resolution methods for three-dimensional protein structure analysis, such as X-ray crystallography and NMR spectroscopy, consists of covalently connecting two functional groups of the protein(s) under investigation. The location of the created cross-links imposes a distance constraint on the location of the respective side chains and allows one to draw conclusions on the three-dimensional structure of the protein or a protein complex. Recently, chemical cross-linking of proteins has been combined with a mass spectrometric analysis of the created cross-linked products. This review article describes the most popular cross-linking reagents for protein structure analysis and gives an overview of the different available strategies that employ chemical cross-linking and different mass spectrometric techniques. The challenges for mass spectrometry caused by the enormous complexity of the cross-linking reaction mixtures are emphasized. The various approaches described in the literature to facilitate the mass spectrometric detection of cross-linked products as well as computer software for data analyses are reviewed.
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Affiliation(s)
- Andrea Sinz
- Biotechnological-Biomedical Center, Faculty of Chemistry and Mineralogy, University of Leipzig, D-04103 Leipzig, Germany.
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Giustarini D, Dalle-Donne I, Cavarra E, Fineschi S, Lungarella G, Milzani A, Rossi R. Metabolism of oxidants by blood from different mouse strains. Biochem Pharmacol 2006; 71:1753-64. [PMID: 16624256 DOI: 10.1016/j.bcp.2006.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 03/15/2006] [Accepted: 03/15/2006] [Indexed: 11/21/2022]
Abstract
Haemoglobins bearing reactive sulfhydryl groups have been shown to be able to interplay with glutathione in some detoxification processes. Blood from different mouse strains commonly used as experimental animal models, i.e., C57, DBA and ICR, was treated with oxidants with the aim of evaluating: (i) the involvement of protein SH groups in oxido-reductive reactions that are commonly carried out by glutathione and (ii) the impact of this phenomenon on blood-mediated metabolism of thiol reactants. All the main forms of glutathione (reduced, disulfide, and mixed disulfide with haemoglobin) were measured after oxidant treatment. Significant differences were found among the studied strains: DBA mice formed preferably mixed disulfides instead of glutathione disulfide, whereas the opposite behaviour was shown by C57 mice. Unexpectedly, the ICR strain resulted to be composed of three different subgroups (ICRa, ICRb, and ICRc), with the ICRa behaving similarly to the DBA strain, ICRc to the C57 strain, and ICRc showing an intermediate behaviour. These results are due to the different number of haemoglobin SH groups in the studied mouse strains. In particular, additional fast-reacting SH groups were found in haemoglobin from DBA, ICRa, and ICRb mice, but not in the C57 and ICRc strain. These differences were also reflected in the susceptibility of haemoglobin to dimerize and in its ability to react with S-nitrosocysteine. Because of the widely different reactivity of haemoglobin cysteinyl residues, the mouse strains examined are an interesting but complicated model in which to study the pharmacological and toxicological action of some drugs.
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Affiliation(s)
- Daniela Giustarini
- Department of Neurosciences, Pharmacology Unit, University of Siena, Via A. Moro 4, 53100 Siena, Italy.
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