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Bou-Abdallah F, Flint N, Wilkinson T, Salim S, Srivastava AK, Poli M, Arosio P, Melman A. Ferritin exhibits Michaelis-Menten behavior with oxygen but not with iron during iron oxidation and core mineralization. Metallomics 2020; 11:774-783. [PMID: 30720039 DOI: 10.1039/c9mt00001a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The excessively high and inconsistent literature values for Km,Fe and Km,O2 prompted us to examine the iron oxidation kinetics in ferritin, the major iron storage protein in mammals, and to determine whether a traditional Michaelis-Menten enzymatic behavior is obeyed. The kinetics of Fe(ii) oxidation and mineralization catalyzed by three different types of ferritins (recombinant human homopolymer 24H, HuHF, human heteropolymer ∼21H:3L, HL, and horse spleen heteropolymer ∼3.3H:20.7L, HosF) were therefore studied under physiologically relevant O2 concentrations, but also in the presence of excess Fe(ii) and O2 concentrations. The observed iron oxidation kinetics exhibited two distinct phases (phase I and phase II), neither of which obeyed Michaelis-Menten kinetics. While phase I was very rapid and corresponded to the oxidation of approximately 2 Fe(ii) ions per H-subunit, phase II was much slower and varied linearly with the concentration of iron(ii) cations in solution, independent of the size of the iron core. Under low oxygen concentration close to physiological, the iron uptake kinetics revealed a Michaelis-Menten behavior with Km,O2 values in the low μM range (i.e. ∼1-2 μM range). Our experimental Km,O2 values are significantly lower than typical cellular oxygen concentration, indicating that iron oxidation and mineralization in ferritin should not be affected by the oxygenation level of cells, and should proceed even under hypoxic events. A kinetic model is proposed in which the inhibition of the protein's activity is caused by bound iron(iii) cations at the ferroxidase center, with the rate limiting step corresponding to an exchange or a displacement reaction between incoming Fe(ii) cations and bound Fe(iii) cations.
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Affiliation(s)
- Fadi Bou-Abdallah
- Department of Chemistry, State University of New York, Potsdam, NY 13676, USA.
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Iron Absorption in Celiac Disease and Nutraceutical Effect of 7-Hydroxymatairesinol. Mini-Review. Molecules 2020; 25:molecules25092041. [PMID: 32349426 PMCID: PMC7249079 DOI: 10.3390/molecules25092041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/19/2020] [Accepted: 04/23/2020] [Indexed: 12/23/2022] Open
Abstract
Anemia is the main extra-gastrointestinal symptom in inflammatory bowel diseases (IBDs). Interleukin-6 (IL-6) and other cytokines are secreted and act in the microenvironment of the small intestine mucous membrane of IBD patients. Iron is essential for multiple cell functions and its homeostasis is regulated by the hepcidin–ferroportin axis. Hepcidin (HEPC) is mainly produced by the liver in response to iron needs but is also an acute phase protein. During inflammation, hepcidin is upregulated by IL-6 and is responsible for iron compartmentalization within cells, in turn causing anemia of inflammation. Tissues other than liver can produce hepcidin in response to inflammatory stimuli, in order to decrease iron efflux at a local level, then acting in an autocrine–paracrine manner. In IBDs and, in particular, in celiac disease (CeD), IL-6 might trigger the expression, upregulation and secretion of hepcidin in the small intestine, reducing iron efflux and exacerbating defective iron absorption. 7-Hydroxymatairesinol (7-HMR) belongs to the family of lignans, polyphenolic compounds produced by plants, and has nutraceutical antioxidant, anti-inflammatory and estrogenic properties. In this mini-review we revise the role of inflammation in IBDs and in particular in CeD, focusing our attention on the close link among inflammation, anemia and iron metabolism. We also briefly describe the anti-inflammatory and estrogenic activity of 7-HMR contained in foods that are often consumed by CeD patients. Finally, considering that HEPC expression is regulated by iron needs, inflammation and estrogens, we explored the hypothesis that 7-HMR consumption could ameliorate anemia in CeD using Caco-2 cells as bowel model. Further studies are needed to verify the regulation pathway through which 7-HMR may interfere with the local production of HEPC in bowel.
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Kang W, Zheng J, Bao J, Wang Z, Zheng Y, He JZ, Hu HW. Characterization of the copper resistance mechanism and bioremediation potential of an Acinetobacter calcoaceticus strain isolated from copper mine sludge. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:7922-7933. [PMID: 31893366 DOI: 10.1007/s11356-019-07303-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 12/04/2019] [Indexed: 06/10/2023]
Abstract
Bioremediation is one of the most effective ways for removal of heavy metals and restoration of contaminated sites. This study investigated the copper (Cu) resistance mechanism and bioremediation potential of an Acinetobacter calcoaceticus strain KW3 isolated from sludge of Cu mine. The effect of Cu concentrations on the bacterial growth, biomass, and adsorption capacity, as well as the effect of contact time on the adsorption process was evaluated in a batch biosorption test. The strain exhibited strong tolerance of Cu, and the minimal inhibitory concentration was around 400 mg Cu2+ L-1, at which the maximum adsorption capacity was 14.1 mg g-1 dry cell mass. Cell walls and intracellular soluble components adsorbed 51.2% and 46.6% of Cu2+, respectively, suggesting that the strain not only adsorbed Cu2+ on the surface but also metastasized ions into cells. The adsorption and kinetic data were well fitted with Freundlich isotherm and Pseudo-second-order models, suggesting that cell surface had a high affinity for Cu2+ and the chemisorption could be the main adsorption mechanism. Scanning electron microscope and Fourier transform infrared spectroscopy analysis revealed that hydroxyl, carboxylic, amide, sulfate, and phosphate on cell walls might be involved in the biosorption process. Two-dimensional gel electrophoresis and MALDI-TOF/TOF mass spectrometry revealed that some oxidoreductases, in particular Cu resistance protein A (CopA) expression levels, were upregulated. Antioxidant defense and P1B-type ATPases CopA efflux might play a crucial role in maintaining cellular homeostasis and intracellular detoxification. To our knowledge, this is the first time that Cu resistance mechanisms, especially intracellular enzymatic mechanisms, were identified in an A. calcoaceticus KW3 strain.
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Affiliation(s)
- Wei Kang
- School of Environmental Science and Engineering, Hubei Key Laboratory of Mine Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
- Hubei Provincial Key Laboratory of Mining Area Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
| | - Jin Zheng
- Hubei Provincial Key Laboratory of Mining Area Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
| | - Jianguo Bao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430070, China
| | - Zhen Wang
- Hubei Provincial Key Laboratory of Mining Area Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430070, China
| | - Yong Zheng
- Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China
| | - Ji-Zheng He
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Hang-Wei Hu
- Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China.
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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54
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Parida A, Mohanty A, Kansara BT, Behera RK. Impact of Phosphate on Iron Mineralization and Mobilization in Nonheme Bacterioferritin B from Mycobacterium tuberculosis. Inorg Chem 2019; 59:629-641. [DOI: 10.1021/acs.inorgchem.9b02894] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Akankshika Parida
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Abhinav Mohanty
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Bharat T. Kansara
- Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Rabindra K. Behera
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
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55
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Pernil R, Schleiff E. Metalloproteins in the Biology of Heterocysts. Life (Basel) 2019; 9:E32. [PMID: 30987221 PMCID: PMC6616624 DOI: 10.3390/life9020032] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/18/2019] [Accepted: 03/28/2019] [Indexed: 12/15/2022] Open
Abstract
Cyanobacteria are photoautotrophic microorganisms present in almost all ecologically niches on Earth. They exist as single-cell or filamentous forms and the latter often contain specialized cells for N₂ fixation known as heterocysts. Heterocysts arise from photosynthetic active vegetative cells by multiple morphological and physiological rearrangements including the absence of O₂ evolution and CO₂ fixation. The key function of this cell type is carried out by the metalloprotein complex known as nitrogenase. Additionally, many other important processes in heterocysts also depend on metalloproteins. This leads to a high metal demand exceeding the one of other bacteria in content and concentration during heterocyst development and in mature heterocysts. This review provides an overview on the current knowledge of the transition metals and metalloproteins required by heterocysts in heterocyst-forming cyanobacteria. It discusses the molecular, physiological, and physicochemical properties of metalloproteins involved in N₂ fixation, H₂ metabolism, electron transport chains, oxidative stress management, storage, energy metabolism, and metabolic networks in the diazotrophic filament. This provides a detailed and comprehensive picture on the heterocyst demands for Fe, Cu, Mo, Ni, Mn, V, and Zn as cofactors for metalloproteins and highlights the importance of such metalloproteins for the biology of cyanobacterial heterocysts.
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Affiliation(s)
- Rafael Pernil
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Straβe 9, 60438 Frankfurt am Main, Germany.
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Straβe 9, 60438 Frankfurt am Main, Germany.
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Straβe 15, 60438 Frankfurt am Main, Germany.
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56
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Mohanty A, Subhadarshanee B, Barman P, Mahapatra C, Aishwarya B, Behera RK. Iron Mineralizing Bacterioferritin A from Mycobacterium tuberculosis Exhibits Unique Catalase-Dps-like Dual Activities. Inorg Chem 2019; 58:4741-4752. [DOI: 10.1021/acs.inorgchem.8b02758] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Abhinav Mohanty
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Biswamaitree Subhadarshanee
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Bhubaneswar 751024, Odisha, India
| | - Pallavi Barman
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Chinmayee Mahapatra
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - B. Aishwarya
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Rabindra K. Behera
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
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57
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Bin S, Pu X, Shu B, Kang C, Luo S, Tang Y, Wu Z, Lin J. Selection of Reference Genes for Optimal Normalization of Quantitative Real-Time Polymerase Chain Reaction Results for Diaphorina citri Adults. JOURNAL OF ECONOMIC ENTOMOLOGY 2019; 112:355-363. [PMID: 30289505 DOI: 10.1093/jee/toy297] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Indexed: 06/08/2023]
Abstract
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), can cause direct damage to citrus trees and is the main vector for the devastating disease, citrus greening disease or huanglongbing. Most molecular studies on this important insect pest use real-time reverse-transcription quantitative polymerase chain reaction (RT-qPCR) to quantify gene expression, including analyzing molecular basis for insecticide resistance in field populations. One critical factor to cause inaccuracy in RT-qPCR results is the lack of appropriate internal reference genes for optimal data normalization. In this study, the expression levels of 10 selected reference genes were evaluated in different tissue samples of psyllid adults and in the insects treated with different temperatures and insecticides. Data were analyzed using different computational algorithms, including Delta Ct, BestKeeper, NormFinder, geNorm, and RefFinder. According to our results, at least two reference genes should be used for the normalization of RT-qPCR data in this insect. The best choices of reference genes for different samples are as follows: ACT1 and Ferritin for different tissue samples, RPS20 and Ferritin for samples treated with different temperatures, TBP and EF1α for samples treated with imidacloprid, and Ferritin and TBP for samples treated with beta-cypermethrin. The reference genes identified in this study should be useful for future studies to analyze the expression patterns of target genes, especially for genes linked with temperature adaptability and insecticide resistance in this insect species in the future.
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Affiliation(s)
- Shuying Bin
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Xinhua Pu
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Benshui Shu
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Cong Kang
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Shaoming Luo
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Yu Tang
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Zhongzhen Wu
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
| | - Jintian Lin
- Guangzhou City Key Laboratory of Subtropical Fruit Trees Outbreak Control, Institute for Management of Invasive Alien Species, Zhongkai University of Agriculture and Engineering, Yingdong Teaching Building, Guangzhou, China
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58
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Koochana PK, Mohanty A, Subhadarshanee B, Satpati S, Naskar R, Dixit A, Behera RK. Phenothiazines and phenoxazines: as electron transfer mediators for ferritin iron release. Dalton Trans 2019; 48:3314-3326. [DOI: 10.1039/c8dt04383c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Redox active phenothiazine and phenoxazine dyes facilitate ferritin iron release by acting as electron transfer (ET) mediators following Marcus theory.
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Affiliation(s)
| | - Abhinav Mohanty
- Department of Chemistry
- National Institute of Technology
- Rourkela-769008
- India
| | | | - Suresh Satpati
- Institute of Life Sciences
- Bhubaneswar-751023
- India
- Indian Institute of Science
- Bangalore-560012
| | - Rajat Naskar
- Department of Chemistry
- National Institute of Technology
- Rourkela-769008
- India
| | | | - Rabindra K. Behera
- Department of Chemistry
- National Institute of Technology
- Rourkela-769008
- India
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59
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Emerging and Dynamic Biomedical Uses of Ferritin. Pharmaceuticals (Basel) 2018; 11:ph11040124. [PMID: 30428583 PMCID: PMC6316788 DOI: 10.3390/ph11040124] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/11/2018] [Accepted: 11/12/2018] [Indexed: 12/14/2022] Open
Abstract
Ferritin, a ubiquitously expressed protein, has classically been considered the main iron cellular storage molecule in the body. Owing to the ferroxidase activity of the H-subunit and the nucleation ability of the L-subunit, ferritin can store a large amount of iron within its mineral core. However, recent evidence has demonstrated a range of abilities of ferritin that extends well beyond the scope of iron storage. This review aims to discuss novel functions and biomedical uses of ferritin in the processes of iron delivery, delivery of biologics such as chemotherapies and contrast agents, and the utility of ferritin as a biomarker in a number of neurological diseases.
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60
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Wofford JD, Bolaji N, Dziuba N, Outten FW, Lindahl PA. Evidence that a respiratory shield in Escherichia coli protects a low-molecular-mass Fe II pool from O 2-dependent oxidation. J Biol Chem 2018; 294:50-62. [PMID: 30337367 DOI: 10.1074/jbc.ra118.005233] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/16/2018] [Indexed: 11/06/2022] Open
Abstract
Iron is critical for virtually all organisms, yet major questions remain regarding the systems-level understanding of iron in whole cells. Here, we obtained Mössbauer and EPR spectra of Escherichia coli cells prepared under different nutrient iron concentrations, carbon sources, growth phases, and O2 concentrations to better understand their global iron content. We investigated WT cells and those lacking Fur, FtnA, Bfr, and Dps proteins. The coarse-grain iron content of exponentially growing cells consisted of iron-sulfur clusters, variable amounts of nonheme high-spin FeII species, and an unassigned residual quadrupole doublet. The iron in stationary-phase cells was dominated by magnetically ordered FeIII ions due to oxyhydroxide nanoparticles. Analysis of cytosolic extracts by size-exclusion chromatography detected by an online inductively coupled plasma mass spectrometer revealed a low-molecular-mass (LMM) FeII pool consisting of two iron complexes with masses of ∼500 (major) and ∼1300 (minor) Da. They appeared to be high-spin FeII species with mostly oxygen donor ligands, perhaps a few nitrogen donors, and probably no sulfur donors. Surprisingly, the iron content of E. coli and its reactivity with O2 were remarkably similar to those of mitochondria. In both cases, a "respiratory shield" composed of membrane-bound iron-rich respiratory complexes may protect the LMM FeII pool from reacting with O2 When exponentially growing cells transition to stationary phase, the shield deactivates as metabolic activity declines. Given the universality of oxidative phosphorylation in aerobic biology, the iron content and respiratory shield in other aerobic prokaryotes might be similar to those of E. coli and mitochondria.
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Affiliation(s)
- Joshua D Wofford
- Department of Chemistry, Texas A&M University, College Station, Texas 77843
| | - Naimah Bolaji
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Nathaniel Dziuba
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - F Wayne Outten
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Paul A Lindahl
- Department of Chemistry, Texas A&M University, College Station, Texas 77843; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843.
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61
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Sala D, Musiani F, Rosato A. Application of Molecular Dynamics to the Investigation of Metalloproteins Involved in Metal Homeostasis. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800602] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Davide Sala
- Magnetic Resonance Center (CERM); University of Florence; Via Luigi Sacconi 6 50019 Sesto Fiorentino Italy
| | - Francesco Musiani
- Laboratory of Bioinorganic Chemistry; Department of Pharmacy and Biotechnology; University of Bologna; Viale Giuseppe Fanin 40, I 40127 Bologna Italy
| | - Antonio Rosato
- Magnetic Resonance Center (CERM); University of Florence; Via Luigi Sacconi 6 50019 Sesto Fiorentino Italy
- Consorzio Interuniversitario di Risonanze Magnetiche di Metallo Proteine; Via Luigi Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
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62
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Gitz JC, Sadot N, Zaccai M, Zarivach R. A Colorimetric Method for Measuring Iron Content in Plants. J Vis Exp 2018:57408. [PMID: 30247485 PMCID: PMC6235139 DOI: 10.3791/57408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Iron, one of the most important micronutrients in living organisms, is involved in basic processes, such as respiration and photosynthesis. Iron content is rather low in all organisms, amounting in plants to about 0.009% of dry weight. To date, one of the most accurate methods for measuring iron concentration in plant tissues is flame absorption atomic spectroscopy. However, this approach is time-consuming and expensive and requires specific equipment not commonly found in plant laboratories. Therefore, a simpler, yet accurate method that can be routinely used is needed. The colorimetric Prussian Blue method is regularly used for qualitative iron staining in animal and plant histological sections. In this study, we adapted the Prussian Blue method for quantitative measurements of iron in tobacco leaves. We validated the accuracy of this method using both atomic spectroscopy and Prussian Blue staining to measure iron content in the same samples and found a linear regression (R2 = 0.988) between the two procedures. We conclude that the Prussian Blue method for quantitative iron measurement in plant tissues is precise, simple, and inexpensive. However, the linear regression presented here may not be appropriate for other plant species, due to potential interactions between the sample and the reagent. Establishment of a regression curve is thus needed for different plant species.
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Affiliation(s)
- Jonas C Gitz
- Department of Life Sciences, Ben-Gurion University of the Negev; National Institute for Biotechnology in the Negev (NIBN);
| | - Noy Sadot
- Department of Life Sciences, Ben-Gurion University of the Negev
| | - Michele Zaccai
- Department of Life Sciences, Ben-Gurion University of the Negev
| | - Raz Zarivach
- Department of Life Sciences, Ben-Gurion University of the Negev; National Institute for Biotechnology in the Negev (NIBN)
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63
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Pietra F. New Vistas on the Recruiting of Ferrous Iron and Dioxygen by Ferritins: A Case Study of the Escherichia coli 24-mer Ferritin by All-Atom Molecular Dynamics in Aqueous Medium. Chem Biodivers 2018; 15:e1800197. [PMID: 29873188 DOI: 10.1002/cbdv.201800197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/04/2018] [Indexed: 12/31/2022]
Abstract
It is shown here that Fe2+ and O2 ligands are displaced from the ferroxidase center of the C1 four-helix bundle of E. coli 24-mer ferritin under molecular dynamics (MD) aided by a randomly oriented external force applied to the ligand. Under these conditions, ligand egress toward the external aqueous medium occurs preferentially from the same four-helix bundle, in the case of O2 , or other bundle, in the case of Fe2 . Viewing ligand egress from the protein as the microscopic reverse of ligand influx into the protein under unbiased MD, these findings challenge current views that preferential gates for recruitment of Fe2+ are 3-fold channels with human ferritin, or the short path from the ferroxidase center to H93 with bacterial ferritins.
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Affiliation(s)
- Francesco Pietra
- Accademia Lucchese di Scienze, Lettere e Arti, Classe di Scienze, Palazzo Pretorio, via Vittorio Veneto 1, 55100, Lucca, Italy
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64
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Feng Y, Wang Q, Chen G, Ye D, Xu W. Impaired renal function and abnormal level of ferritin are independent risk factors of left ventricular aneurysm after acute myocardial infarction: A hospital-based case-control study. Medicine (Baltimore) 2018; 97:e12109. [PMID: 30170438 PMCID: PMC6393115 DOI: 10.1097/md.0000000000012109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study was performed to determine the prognostic value of glomerular filtration rate (GFR) and ferritin compromised in left ventricular aneurysm (LVA) patients who suffered acute myocardial infarction (AMI) beforehand.A hospital-based case-control study was conducted in the Department of Cardiology, First Affiliated Hospital, Zhejiang University in 2013 and 2014. Patients were divided into 3 groups according to kidney function and ferritin level. Observation outcomes include age, sex, C-reaction protein (CRP), medical history including major risk factors for CAD, ferritin and GFR, previous angina, time between MI and coronary angiography or time to rescue (TTR), and prior treatment.Around 60 patients were included in the case group (AMI with LVA) and 133 matched patients (AMI without LVA) in the control group. The prevalence of single-vessel disease (odd ratio [OR] = 2.490; 95% confidential interval [95% CI] = 1.376-4.506; P = .002), total LAD occlusion (OR = 1.897; 95% CI = 1.024-3.515; P = .041), absence of previous angina (OR = 1.930; 95% CI = 1.035-3.600; P = .037), time between myocardial infraction (MI) and coronary angiography more than 12 h (OR = 1.970; 95% CI = 1.044-3.719; P = .035), GFR less than 60 mL/min (OR = 2.933; 95% CI = 1.564-5.503; P = .001), and ferritin levels (P = .0003) were all higher in the aneurysm group compared with those in the control group. After adjustments for other variables, single-vessel disease (OR = 1.211; 95% CI = 1.080-1.342; P = .02), GFR lower than 60 mL/min (OR = 1.651; 95% CI = 1.250-2.172; P = .013), and high or low levels of ferritin (OR = 1.151; 95% CI = 1.050-1.252; P = .042) remained the independent determinants of LVA formation after AMI.Decreased GFR and abnormal ferritin levels are independent risk factors of LVA formation after AMI.
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Affiliation(s)
- Yunfei Feng
- The Department of Endocrinology and Metabolism
| | - Qiqi Wang
- the Department of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | | | - Dan Ye
- The Department of Endocrinology and Metabolism
| | - Weiwei Xu
- The Department of Endocrinology and Metabolism
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Hagen WR, Hagedoorn PL, Honarmand Ebrahimi K. The workings of ferritin: a crossroad of opinions. Metallomics 2018; 9:595-605. [PMID: 28573266 DOI: 10.1039/c7mt00124j] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Biochemistry of the essential element iron is complicated by radical chemistry associated with Fe(ii) ions and by the extremely low solubility of the Fe(iii) ion in near-neutral water. To mitigate these problems cells from all domains of life synthesize the protein ferritin to take up and oxidize Fe(ii) and to form a soluble storage of Fe(iii) from which iron can be made available for physiology. A long history of studies on ferritin has not yet resulted in a generally accepted mechanism of action of this enzyme. In fact strong disagreement exists between extant ideas on several key steps in the workings of ferritin. The scope of this review is to explain the experimental background of these controversies and to indicate directions towards their possible resolution.
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Affiliation(s)
- Wilfred R Hagen
- Delft University of Technology, Department of Biotechnology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
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Eshelman K, Yao H, Punchi Hewage AND, Deay JJ, Chandler JR, Rivera M. Inhibiting the BfrB:Bfd interaction in Pseudomonas aeruginosa causes irreversible iron accumulation in bacterioferritin and iron deficiency in the bacterial cytosol. Metallomics 2018; 9:646-659. [PMID: 28318006 DOI: 10.1039/c7mt00042a] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron is an essential nutrient for bacteria but the reactivity of Fe2+ and the insolubility of Fe3+ present significant challenges to bacterial cells. Iron storage proteins contribute to ameliorating these challenges by oxidizing Fe2+ using O2 and H2O2 as electron acceptors, and by compartmentalizing Fe3+. Two types of iron-storage proteins coexist in bacteria, the ferritins (Ftn) and the heme-containing bacterioferritins (Bfr), but the reasons for their coexistence are largely unknown. P. aeruginosa cells harbor two iron storage proteins (FtnA and BfrB), but nothing is known about their relative contributions to iron homeostasis. Prior studies in vitro have shown that iron mobilization from BfrB requires specific interactions with a ferredoxin (Bfd), but the relevance of the BfrB:Bfd interaction to iron homeostasis in P. aeruginosa is unknown. In this work we explore the repercussions of (i) deleting the bfrB gene, and (ii) perturbing the BfrB:Bfd interaction in P. aeruginosa cells by either deleting the bfd gene or by replacing the wild type bfrB gene with a L68A/E81A double mutant allele in the P. aeruginosa chromosome. The effects of the mutations were evaluated by following the accumulation of iron in BfrB, analyzing levels of free and total intracellular iron, and by characterizing the ensuing iron homeostasis dysregulation phenotypes. The results reveal that P. aeruginosa accumulates iron mainly in BfrB, and that the nutrient does not accumulate in FtnA to detectable levels, even after deletion of the bfrB gene. Perturbing the BfrB:Bfd interaction causes irreversible flow of iron into BfrB, which leads to the accumulation of unusable intracellular iron while severely depleting the levels of free intracellular iron, which drives the cells to an acute iron starvation response despite harboring "normal" levels of total intracellular iron. These results are discussed in the context of a dynamic equilibrium between free cytosolic Fe2+ and Fe3+ compartmentalized in BfrB, which functions as a buffer to oppose rapid changes of free cytosolic iron. Finally, we also show that P. aeruginosa cells utilize iron stored in BfrB for growth in iron-limiting conditions, and that the utilization of BfrB-iron requires a functional BfrB:Bfd interaction.
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Affiliation(s)
- Kate Eshelman
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr, Lawrence, KS 66047, USA.
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López P, Castro A, Flórez M, Miranda K, Aranda P, Sánchez-González C, Llopis J, Arredondo M. miR-155 and miR-122 Expression of Spermatozoa in Obese Subjects. Front Genet 2018; 9:175. [PMID: 29896216 PMCID: PMC5986881 DOI: 10.3389/fgene.2018.00175] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/27/2018] [Indexed: 01/20/2023] Open
Abstract
Obesity is characterized by mild chronic inflammation that is linked with impaired iron homeostasis. Studies in human and murine show that there is a transgenerational epigenetic inheritance via the gametes in obesity; however, there is little information on changes in the expression of microRNAs related to inflammation and iron homeostasis in spermatozoa from obese subjects. The present study investigated the expression of microRNAs related to inflammation (miR-21 y miR-155) and iron nutrition (miR-122 and miR-200b) in plasma, peripheral blood mononuclear cells (PBMC) and spermatozoa from normozoospermic controls (Cn; n = 17; BMI: 24.6 ± 2.0) and obese (Ob; n = 17; BMI: 32.6 ± 4.4) men. To determine the inflammation levels, we measured IL-6, TNF-α, and monocyte chemoattractant protein-1 (MCP1) by Magnetic Luminex® Assay. mRNA expression of IL6, TNF-α, and hepcidin (HAMP) in PBMC were evaluated by RT-qPCR. The analysis of microRNAs was performed using the Taqman® assays. The iron content in PBMC, seminal plasma, and spermatozoa was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). High serum IL6, TNF-α, and MCP1 levels were observed in Ob group (p < 0.05). Gene expression analysis showed an increased abundance relative of TNF-α (p = 0.018), HAMP (p = 0.03), and IL6 (p = 0.02) in PBMC from obese subjects. Also, we observed high levels of serum ferritin (p = 0.03), iron content in seminal plasma (p = 0.04), and spermatozoa (p = 0.002), but lower serum Fe (p = 0.007) in obese subjects. In the Ob group, a high expression of miR-155 (p = 0.02) and miR-21 (p = 0.03) was observed in PBMC and miR-122 (p = 0.03) in plasma. In sperm, both miR-155 (p = 0.004) and miR-122 (p = 0.028) were high in the Ob group. Our results showed that obese subjects have increased expressions of miR-155 and miR-122, two microRNAs that were previously related with inflammation and iron metabolism, respectively, at both the systemic and sperm levels.
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Affiliation(s)
- Paulina López
- Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile
| | - Andrea Castro
- Institute of Maternal and Child Research, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Martha Flórez
- Institute of Maternal and Child Research, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Karen Miranda
- Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile
| | - Pilar Aranda
- CIBM, INYTA, IMUDS, Department of Physiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Cristina Sánchez-González
- CIBM, INYTA, IMUDS, Department of Physiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Juan Llopis
- CIBM, INYTA, IMUDS, Department of Physiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Miguel Arredondo
- Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile
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Ferritin from the haemolymph of adult ants: an extraction method for characterization and a ferromagnetic study. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:641-653. [DOI: 10.1007/s00249-018-1293-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/05/2018] [Accepted: 03/13/2018] [Indexed: 01/03/2023]
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69
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Koochana PK, Mohanty A, Das S, Subhadarshanee B, Satpati S, Dixit A, Sabat SC, Behera RK. Releasing iron from ferritin protein nanocage by reductive method: The role of electron transfer mediator. Biochim Biophys Acta Gen Subj 2018; 1862:1190-1198. [PMID: 29471025 DOI: 10.1016/j.bbagen.2018.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Ferritin detoxifies excess of free Fe(II) and concentrates it in the form of ferrihydrite (Fe2O3·xH2O) mineral. When in need, ferritin iron is released for cellular metabolic activities. However, the low solubility of Fe(III) at neutral pH, its encapsulation by stable protein nanocage and presence of dissolved O2 limits in vitro ferritin iron release. METHODS Physiological reducing agent, NADH (E1/2 = -330 mV) was inefficient in releasing the ferritin iron (E1/2 = +183 mV), when used alone. Thus, current work investigates the role of low concentration (5-50 μM) of phenazine based electron transfer (ET) mediators such as FMN, PYO - a redox active virulence factor secreted by Pseudomonas aeruginosa and PMS towards iron mobilization from recombinant frog M ferritin. RESULTS The presence of dissolved O2, resulting in initial lag phase and low iron release in FMN, had little impact in case of PMS and PYO, reflecting their better ET relay ability that facilitates iron mobilization. The molecular modeling as well as fluorescence studies provided further structural insight towards interaction of redox mediators on ferritin surface for electron relay. CONCLUSIONS Reductive mobilization of iron from ferritin is dependent on the relative rate of NADH oxidation, dissolved O2 consumption and mineral core reduction, which in turn depends on E1/2 of these mediators and their interaction with ferritin. GENERAL SIGNIFICANCE The current mechanism of in vitro iron mobilization from ferritin by using redox mediators involves different ET steps, which may help to understand the iron release pathway in vivo and to check microbial growth.
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Affiliation(s)
| | - Abhinav Mohanty
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Suman Das
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Biswamaitree Subhadarshanee
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India; KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Suresh Satpati
- Institute of Life Sciences, Bhubaneswar 751023, Odisha, India
| | - Anshuman Dixit
- Institute of Life Sciences, Bhubaneswar 751023, Odisha, India
| | | | - Rabindra K Behera
- Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India.
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70
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Kamnev AA, Tugarova AV. Sample treatment in Mössbauer spectroscopy for protein-related analyses: Nondestructive possibilities to look inside metal-containing biosystems. Talanta 2017; 174:819-837. [PMID: 28738659 DOI: 10.1016/j.talanta.2017.06.057] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/01/2017] [Accepted: 06/19/2017] [Indexed: 01/07/2023]
Abstract
In this review, the unique possibilities are considered of the 57Fe transmission (TMS) and 57Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues. Recent representative examples of analyses of Fe-containing proteins by 57Fe TMS are briefly discussed, along with the newly emerging data on using 57Co EMS for probing the structural organisation of 57Co-doped cation-binding sites in sophisticated biocomplexes including metalloenzymes. Finally, some rare or exotic applications of Mössbauer spectroscopy (including the synchrotron-based methodology) in protein-related studies are outlined.
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Affiliation(s)
- Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia.
| | - Anna V Tugarova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia
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71
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Blaby-Haas CE, Merchant SS. Regulating cellular trace metal economy in algae. CURRENT OPINION IN PLANT BIOLOGY 2017; 39:88-96. [PMID: 28672168 PMCID: PMC5595633 DOI: 10.1016/j.pbi.2017.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/09/2017] [Accepted: 06/12/2017] [Indexed: 05/05/2023]
Abstract
As indispensable protein cofactors, Fe, Mn, Cu and Zn are at the center of multifaceted acclimation mechanisms that have evolved to ensure extracellular supply meets intracellular demand. Starting with selective transport at the plasma membrane and ending in protein metalation, metal homeostasis in algae involves regulated trafficking of metal ions across membranes, intracellular compartmentalization by proteins and organelles, and metal-sparing/recycling mechanisms to optimize metal-use efficiency. Overlaid on these processes are additional circuits that respond to the metabolic state as well as to the prior metal status of the cell. In this review, we focus on recent progress made toward understanding the pathways by which the single-celled, green alga Chlamydomonas reinhardtii controls its cellular trace metal economy. We also compare these mechanisms to characterized and putative processes in other algal lineages. Photosynthetic microbes continue to provide insight into cellular regulation and handling of Cu, Fe, Zn and Mn as a function of the nutritional supply and cellular demand for metal cofactors. New experimental tools such as RNA-Seq and subcellular metal imaging are bringing us closer to a molecular understanding of acclimation to supply dynamics in algae and beyond.
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Affiliation(s)
- Crysten E Blaby-Haas
- Biology Department, Brookhaven National Laboratory, 50 Bell Avenue, Building 463, Upton, NY 11973, USA.
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, USA; Institute for Genomics and Proteomics, University of California, Los Angeles, 611 Charles E. Young Drive East, Los Angeles, USA
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72
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Nanoscale iron particles formed from the metalloprotein-like structures prepared using ferrous ions in the presence of sodium glutamate and bovine serum albumin. MONATSHEFTE FUR CHEMIE 2017. [DOI: 10.1007/s00706-017-2030-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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73
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Sala D, Ciambellotti S, Giachetti A, Turano P, Rosato A. Investigation of the Iron(II) Release Mechanism of Human H-Ferritin as a Function of pH. J Chem Inf Model 2017; 57:2112-2118. [DOI: 10.1021/acs.jcim.7b00306] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Davide Sala
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Silvia Ciambellotti
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Andrea Giachetti
- Consorzio Interuniversitario di Risonanze Magnetiche di Metallo Proteine, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Paola Turano
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Department
of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Antonio Rosato
- Magnetic
Resonance Center (CERM), University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Department
of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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74
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Soldatova AV, Tao L, Romano CA, Stich TA, Casey WH, Britt RD, Tebo BM, Spiro TG. Mn(II) Oxidation by the Multicopper Oxidase Complex Mnx: A Binuclear Activation Mechanism. J Am Chem Soc 2017; 139:11369-11380. [PMID: 28712284 DOI: 10.1021/jacs.7b02771] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The bacterial protein complex Mnx contains a multicopper oxidase (MCO) MnxG that, unusually, catalyzes the two-electron oxidation of Mn(II) to MnO2 biomineral, via a Mn(III) intermediate. Although Mn(III)/Mn(II) and Mn(IV)/Mn(III) reduction potentials are expected to be high, we find a low reduction potential, 0.38 V (vs Normal Hydrogen Electrode, pH 7.8), for the MnxG type 1 Cu2+, the electron acceptor. Indeed the type 1 Cu2+ is not reduced by Mn(II) in the absence of molecular oxygen, indicating that substrate oxidation requires an activation step. We have investigated the enzyme mechanism via electronic absorption spectroscopy, using chemometric analysis to separate enzyme-catalyzed MnO2 formation from MnO2 nanoparticle aging. The nanoparticle aging time course is characteristic of nucleation and particle growth; rates for these processes followed expected dependencies on Mn(II) concentration and temperature, but exhibited different pH optima. The enzymatic time course is sigmoidal, signaling an activation step, prior to turnover. The Mn(II) concentration and pH dependence of a preceding lag phase indicates weak Mn(II) binding. The activation step is enabled by a pKa > 8.6 deprotonation, which is assigned to Mn(II)-bound H2O; it induces a conformation change (consistent with a high activation energy, 106 kJ/mol) that increases Mn(II) affinity. Mnx activation is proposed to decrease the Mn(III/II) reduction potential below that of type 1 Cu(II/I) by formation of a hydroxide-bridged binuclear complex, Mn(II)(μ-OH)Mn(II), at the substrate site. Turnover is found to depend cooperatively on two Mn(II) and is enabled by a pKa 7.6 double deprotonation. It is proposed that turnover produces a Mn(III)(μ-OH)2Mn(III) intermediate that proceeds to the enzyme product, likely Mn(IV)(μ-O)2Mn(IV) or an oligomer, which subsequently nucleates MnO2 nanoparticles. We conclude that Mnx exploits manganese polynuclear chemistry in order to facilitate an otherwise difficult oxidation reaction, as well as biomineralization. The mechanism of the Mn(III/IV) conversion step is elucidated in an accompanying paper .
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Affiliation(s)
- Alexandra V Soldatova
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
| | | | - Christine A Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | | | | | | | - Bradley M Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | - Thomas G Spiro
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
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75
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Vaccaro BJ, Clarkson SM, Holden JF, Lee DW, Wu CH, Poole Ii FL, Cotelesage JJH, Hackett MJ, Mohebbi S, Sun J, Li H, Johnson MK, George GN, Adams MWW. Biological iron-sulfur storage in a thioferrate-protein nanoparticle. Nat Commun 2017; 8:16110. [PMID: 28726794 PMCID: PMC5524996 DOI: 10.1038/ncomms16110] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
Iron–sulfur clusters are ubiquitous in biology and function in electron transfer and catalysis. They are assembled from iron and cysteine sulfur on protein scaffolds. Iron is typically stored as iron oxyhydroxide, ferrihydrite, encapsulated in 12 nm shells of ferritin, which buffers cellular iron availability. Here we have characterized IssA, a protein that stores iron and sulfur as thioferrate, an inorganic anionic polymer previously unknown in biology. IssA forms nanoparticles reaching 300 nm in diameter and is the largest natural metalloprotein complex known. It is a member of a widely distributed protein family that includes nitrogenase maturation factors, NifB and NifX. IssA nanoparticles are visible by electron microscopy as electron-dense bodies in the cytoplasm. Purified nanoparticles appear to be generated from 20 nm units containing ∼6,400 Fe atoms and ∼170 IssA monomers. In support of roles in both iron–sulfur storage and cluster biosynthesis, IssA reconstitutes the [4Fe-4S] cluster in ferredoxin in vitro. The biosynthesis of iron-sulfur clusters in anaerobic organisms has not been extensively investigated. Here, the authors identify and characterize a multi-subunit protein that stores iron and sulfur in thioferrate for the assembly of the clusters in Pyrococcus furiosus.
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Affiliation(s)
- Brian J Vaccaro
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Sonya M Clarkson
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - James F Holden
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Dong-Woo Lee
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Farris L Poole Ii
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Julien J H Cotelesage
- Department of Geological Sciences and Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C5, Canada
| | - Mark J Hackett
- Department of Geological Sciences and Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C5, Canada
| | - Sahel Mohebbi
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Jingchuan Sun
- Cryo-EM Structural Biology Laboratory, Center for Epigenetics, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - Huilin Li
- Cryo-EM Structural Biology Laboratory, Center for Epigenetics, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | - Michael K Johnson
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Graham N George
- Department of Geological Sciences and Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C5, Canada
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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Chen R, Chen G. Tumor-induced disorder of iron metabolism in major organs: a new insight from chemical speciation of iron. J Int Med Res 2017; 46:70-78. [PMID: 28718696 PMCID: PMC6011321 DOI: 10.1177/0300060517718711] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Objective To investigate the evolution of iron speciation in major organs of tumor-bearing mice and its role in cancer formation and cancer-associated complications. Methods The concentration and chemical speciation of iron in the spleen, liver, lung, kidney, heart, blood, muscle, and tumor tissue of healthy mice and tumor-bearing mice were studied by synchrotron radiation-based total reflection X-ray fluorescence spectrometry (SR-TXRF) coupled with X-ray absorption spectroscopy (XAS). Results The TXRF and XAS results showed that the iron content, especially the ferritin content, significantly decreased in the blood and spleen but significantly increased in the liver, lung, and muscle of mice after tumor implantation. The chemical speciation of iron in the tumor mainly comprised ferrous-sulfide-like iron and ferritin. Conclusion The tumors disturbed the iron metabolism in major organs, and the evolution of iron may be involved in iron deficiency anemia, cancer growth, and immunity. Additionally, iron speciation-based markers may be further developed as clinical indicators for cancer and cancer-associated complications.
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Affiliation(s)
- Rujie Chen
- 1 Department of Anesthesiology, Critical Care, and Pain Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Guangcun Chen
- 2 Division of Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China
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77
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Diversity of Fe 2+ entry and oxidation in ferritins. Curr Opin Chem Biol 2017; 37:122-128. [DOI: 10.1016/j.cbpa.2017.02.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 01/08/2023]
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78
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Meinert C, Brandt U, Heine V, Beyert J, Schmidl S, Wübbeler JH, Voigt B, Riedel K, Steinbüchel A. Proteomic analysis of organic sulfur compound utilisation in Advenella mimigardefordensis strain DPN7T. PLoS One 2017; 12:e0174256. [PMID: 28358882 PMCID: PMC5373536 DOI: 10.1371/journal.pone.0174256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/06/2017] [Indexed: 01/07/2023] Open
Abstract
2-Mercaptosuccinate (MS) and 3,3´-ditiodipropionate (DTDP) were discussed as precursor substance for production of polythioesters (PTE). Therefore, degradation of MS and DTDP was investigated in Advenella mimigardefordensis strain DPN7T, applying differential proteomic analysis, gene deletion and enzyme assays. Protein extracts of cells cultivated with MS, DTDP or 3-sulfinopropionic acid (SP) were compared with those cultivated with propionate (P) and/or succinate (S). The chaperone DnaK (ratio DTDP/P 9.2, 3SP/P 4.0, MS/S 6.1, DTDP/S 6.2) and a Do-like serine protease (DegP) were increased during utilization of all organic sulfur compounds. Furthermore, a putative bacterioferritin (locus tag MIM_c12960) showed high abundance (ratio DTDP/P 5.3, 3SP/P 3.2, MS/S 4.8, DTDP/S 3.9) and is probably involved in a thiol-specific stress response. The deletion of two genes encoding transcriptional regulators (LysR (MIM_c31370) and Xre (MIM_c31360)) in the close proximity of the relevant genes of DTDP catabolism (acdA, mdo and the genes encoding the enzymes of the methylcitric acid cycle; prpC,acnD, prpF and prpB) showed that these two regulators are essential for growth of A. mimigardefordensis strain DPN7T with DTDP and that they most probably regulate transcription of genes mandatory for this catabolic pathway. Furthermore, proteome analysis revealed a high abundance (ratio MS/S 10.9) of a hypothetical cupin-2-domain containing protein (MIM_c37420). This protein shows an amino acid sequence similarity of 60% to a newly identified MS dioxygenase from Variovorax paradoxus strain B4. Deletion of the gene and the adjacently located transcriptional regulator LysR, as well as heterologous expression of MIM_c37420, the putative mercaptosuccinate dioxygenase (Msdo) from A. mimigardefordensis, showed that this protein is the key enzyme of MS degradation in A. mimigardefordensis strain DPN7T (KM 0.2 mM, specific activity 17.1 μmol mg-1 min-1) and is controlled by LysR (MIM_c37410).
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Affiliation(s)
- Christina Meinert
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Ulrike Brandt
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Viktoria Heine
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Jessica Beyert
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Sina Schmidl
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Jan Hendrik Wübbeler
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Birgit Voigt
- Institut für Mikrobiologie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany
| | - Katharina Riedel
- Institut für Mikrobiologie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
- Environmental Science Department, King Abdulaziz University, Jeddah, Saudi Arabia
- * E-mail:
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79
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Rivera M. Bacterioferritin: Structure, Dynamics, and Protein-Protein Interactions at Play in Iron Storage and Mobilization. Acc Chem Res 2017; 50:331-340. [PMID: 28177216 PMCID: PMC5358871 DOI: 10.1021/acs.accounts.6b00514] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite its essentiality to life, iron presents significant challenges to cells: the exceedingly low solubility of Fe3+ limits its bioavailability, and the reactivity of Fe2+ toward H2O2 is a source of the toxic hydroxyl radical (HO•). Consequently, cellular levels of free iron are highly regulated to ensure sufficiency while preventing iron-induced toxicity. Relatively little is known about the fate of iron in the bacterial cytosol or how cells balance the need for relatively high cytosolic iron concentrations with the potential toxicity of the nutrient. Iron storage proteins are integral to iron metabolism, and bacteria utilize two types of ferritin-like molecules to store iron, bacterial ferritin (Ftn) and bacterioferritin (Bfr). Ftn and Bfr compartmentalize iron at concentrations far above the solubility of Fe3+ and protect the reducing cell environment from unwanted Fe3+/Fe2+ redox cycling. This Account focuses on our laboratory's efforts to study iron storage proteins in the model bacterium Pseudomonas aeruginosa, an opportunistic pathogen. Prior to our studies, it was thought that P. aeruginosa cells relied on a single Bfr assembled from two distinct subunits coded by the bfrA and bfrB genes. It is now known that, like in most bacteria, two iron storage proteins coexist in P. aeruginosa cells, a bacterial Ftn (FtnA), coded by the ftnA (formerly bfrA) gene and a bacterioferritin (BfrB), coded by the bfrB gene. Studies with BfrB showed that Fe2+ oxidation occurs at ferroxidase centers (FCs), followed by gated translocation of Fe3+ to the interior cavity, a process that is, surprisingly, distinct from that observed with the extensively studied Bfr from Escherichia coli, where the FCs are stable and function only as a catalytic site for O2 reduction. Investigations with BfrB showed that the oxidation of Fe2+ at FCs and the internalization of Fe3+ depend on long-range cooperative motions, extending from 4-fold pores, via B-pores, into FCs. It remains to be seen whether similar studies with E. coli Bfr will reveal distinct cooperative motions contributing to the stability of its FCs. Mobilization of Fe3+ stored in BfrB requires interaction with a ferredoxin (Bfd), which transfers electrons to reduce Fe3+ in the internal cavity of BfrB for subsequent release of Fe2+. The structure of the BfrB/Bfd complex furnished the only known structure of a ferritin molecule in complex with a physiological protein partner. The BfrB/Bfd complex is stabilized by hot-spot residues in both proteins, which interweave into a highly complementary hot region. The hot-spot residues are conserved in the sequences of Bfr and Bfd proteins from a number of bacteria, indicating that the BfrB/Bfd interaction is of widespread significance in bacterial iron metabolism. The BfrB/Bfd structure also furnished the only known structure of a Bfd, which revealed a novel helix-turn-helix fold different from the β-strand and α-helix fold of plant and vertebrate [2Fe-2S]-ferredoxins. Bfds seem to be unique to bacteria; consequently, although mobilization of iron from eukaryotic ferritins may also be facilitated by protein-protein interactions, the nature of the protein that delivers electrons to the ferric core of eukaryotic ferritins remains unknown.
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Affiliation(s)
- Mario Rivera
- Department of Chemistry and Ralph N. Adams
Institute for Bioanalytical Chemistry, University of Kansas, 2030 Becker
Dr., Lawrence, Kansas 66047, United States
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80
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Bradley JM, Svistunenko DA, Moore GR, Le Brun NE. Tyr25, Tyr58 and Trp133 ofEscherichia colibacterioferritin transfer electrons between iron in the central cavity and the ferroxidase centre. Metallomics 2017; 9:1421-1428. [DOI: 10.1039/c7mt00187h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tyr58 and Trp133 play key roles in the formation and decay of the Tyr25 radical species ofE. coliBFR.
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Affiliation(s)
- Justin M. Bradley
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
| | | | - Geoffrey R. Moore
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
| | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
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81
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Theil EC, Tosha T, Behera RK. Solving Biology's Iron Chemistry Problem with Ferritin Protein Nanocages. Acc Chem Res 2016; 49:784-91. [PMID: 27136423 DOI: 10.1021/ar500469e] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ferritins reversibly synthesize iron-oxy(ferrihydrite) biominerals inside large, hollow protein nanocages (10-12 nm, ∼480 000 g/mol); the iron biominerals are metabolic iron concentrates for iron protein biosyntheses. Protein cages of 12- or 24-folded ferritin subunits (4-α-helix polypeptide bundles) self-assemble, experimentally. Ferritin biomineral structures differ among animals and plants or bacteria. The basic ferritin mineral structure is ferrihydrite (Fe2O3·H2O) with either low phosphate in the highly ordered animal ferritin biominerals, Fe/PO4 ∼ 8:1, or Fe/PO4 ∼ 1:1 in the more amorphous ferritin biominerals of plants and bacteria. While different ferritin environments, plant bacterial-like plastid organelles and animal cytoplasm, might explain ferritin biomineral differences, investigation is required. Currently, the physiological significance of plant-specific and animal-specific ferritin iron minerals is unknown. The iron content of ferritin in living tissues ranges from zero in "apoferritin" to as high as ∼4500 iron atoms. Ferritin biomineralization begins with the reaction of Fe(2+) with O2 at ferritin enzyme (Fe(2+)/O oxidoreductase) sites. The product of ferritin enzyme activity, diferric oxy complexes, is also the precursor of ferritin biomineral. Concentrations of Fe(3+) equivalent to 2.0 × 10(-1) M are maintained in ferritin solutions, contrasting with the Fe(3+) Ks ∼ 10(-18) M. Iron ions move into, through, and out of ferritin protein cages in structural subdomains containing conserved amino acids. Cage subdomains include (1) ion channels for Fe(2+) entry/exit, (2) enzyme (oxidoreductase) site for coupling Fe(2+) and O yielding diferric oxy biomineral precursors, and (3) ferric oxy nucleation channels, where diferric oxy products from up to three enzyme sites interact while moving toward the central, biomineral growth cavity (12 nm diameter) where ferric oxy species, now 48-mers, grow in ferric oxy biomineral. High ferritin protein cage symmetry (3-fold and 4-fold axes) and amino acid conservation coincide with function, shown by amino acid substitution effects. 3-Fold symmetry axes control Fe(2+) entry (enzyme catalysis of Fe(2+)/O2 oxidoreduction) and Fe(2+) exit (reductive ferritin mineral dissolution); 3-fold symmetry axes influence Fe(2+)exit from dissolved mineral; bacterial ferritins diverge slightly in Fe/O2 reaction mechanisms and intracage paths of iron-oxy complexes. Biosynthesis rates of ferritin protein change with Fe(2+) and O2 concentrations, dependent on DNA-binding, and heme binding protein, Bach 1. Increased cellular O2 indirectly stabilizes ferritin DNA/Bach 1 interactions. Heme, Fe-protoporphyrin IX, decreases ferritin DNA-Bach 1 binding, causing increased ferritin mRNA biosynthesis (transcription). Direct Fe(2+) binding to ferritin mRNA decreases binding of an inhibitory protein, IRP, causing increased ferritin mRNA translation (protein biosynthesis). Newly synthesized ferritin protein consumes Fe(2+) in biomineral, decreasing Fe(2)(+) and creating a regulatory feedback loop. Ferritin without iron is "apoferritin". Iron removal from ferritin, experimentally, uses biological reductants, for example, NADH + FMN, or chemical reductants, for example, thioglycolic acid, with Fe(2+) chelators; physiological mechanism(s) are murky. Clear, however, is the necessity of ferritin for terrestrial life by conferring oxidant protection (plants, animals, and bacteria), virulence (bacteria), and embryonic survival (mammals). Future studies of ferritin structure/function and Fe(2+)/O2 chemistry will lead to new ferritin uses in medicine, nutrition, and nanochemistry.
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Affiliation(s)
- Elizabeth C. Theil
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
| | - Takehiko Tosha
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
| | - Rabindra K. Behera
- Children’s Hospital Oakland Research Institute, Oakland, California 94609, United States
- Department of Structural
and Molecular Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7313, United States
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