101
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Yang Y, Wang X, Cui Q, Cao Q, Li L. Self-Assembly of Fluorescent Organic Nanoparticles for Iron(III) Sensing and Cellular Imaging. ACS APPLIED MATERIALS & INTERFACES 2016; 8:7440-8. [PMID: 26950776 DOI: 10.1021/acsami.6b00065] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fluorescent organic nanoparticles have attracted increasing attentions for chemical or biological sensing and imaging due to their low-toxicity, facile fabrication and surface functionalization. In this work, we report novel fluorescent organic nanoparticles via facile self-assembly method in aqueous solution. First, the designed water-soluble fluorophore shows a weak and negligible intrinsic fluorescence in water. Upon binding with adenosine-5'-triphosphate (ATP), fluorescent nanoparticles were formed immediately with strongly enhanced fluorescence. These fluorescent nanoparticles exhibit high sensitivity and selectivity toward Fe(3+) sensing with detection limit of 0.1 nM. In addition, after incubation with HeLa cells, the fluorophore shows excellent imaging performance by interaction with entogenous ATP in cells. Finally, this fluorescent system is also demonstrated to be capable of Fe(3+) sensing via fluorescence quenching in cellular environment.
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Affiliation(s)
- Yu Yang
- School of Materials Science and Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Xiaoyu Wang
- School of Materials Science and Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Qianling Cui
- School of Materials Science and Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Qian Cao
- School of Materials Science and Engineering, University of Science and Technology Beijing , Beijing 100083, China
| | - Lidong Li
- School of Materials Science and Engineering, University of Science and Technology Beijing , Beijing 100083, China
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102
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Surmik D, Boczarowski A, Balin K, Dulski M, Szade J, Kremer B, Pawlicki R. Spectroscopic Studies on Organic Matter from Triassic Reptile Bones, Upper Silesia, Poland. PLoS One 2016; 11:e0151143. [PMID: 26977600 PMCID: PMC4792425 DOI: 10.1371/journal.pone.0151143] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/24/2016] [Indexed: 11/19/2022] Open
Abstract
Fossil biomolecules from an endogenous source were previously identified in Cretaceous to Pleistocene fossilized bones, the evidence coming from molecular analyses. These findings, however, were called into question and an alternative hypothesis of the invasion of the bone by bacterial biofilm was proposed. Herewith we report a new finding of morphologically preserved blood-vessel-like structures enclosing organic molecules preserved in iron-oxide-mineralized vessel walls from the cortical region of nothosaurid and tanystropheid (aquatic and terrestrial diapsid reptiles) bones. These findings are from the Early/Middle Triassic boundary (Upper Roetian/Lowermost Muschelkalk) strata of Upper Silesia, Poland. Multiple spectroscopic analyses (FTIR, ToF-SIMS, and XPS) of the extracted "blood vessels" showed the presence of organic compounds, including fragments of various amino acids such as hydroxyproline and hydroxylysine as well as amides, that may suggest the presence of collagen protein residues. Because these amino acids are absent from most proteins other than collagen, we infer that the proteinaceous molecules may originate from endogenous collagen. The preservation of molecular signals of proteins within the "blood vessels" was most likely made possible through the process of early diagenetic iron oxide mineralization. This discovery provides the oldest evidence of in situ preservation of complex organic molecules in vertebrate remains in a marine environment.
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Affiliation(s)
- Dawid Surmik
- Faculty of Earth Science, University of Silesia, Będzińska 60, 41–200, Sosnowiec, Poland
- Park of Science & Human Evolution, 1 Maja 10, 46–040, Krasiejów, Poland
| | - Andrzej Boczarowski
- Faculty of Earth Science, University of Silesia, Będzińska 60, 41–200, Sosnowiec, Poland
- Park of Science & Human Evolution, 1 Maja 10, 46–040, Krasiejów, Poland
| | - Katarzyna Balin
- A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40–007, Katowice, Poland
- Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland
| | - Mateusz Dulski
- Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland
- Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland
| | - Jacek Szade
- A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40–007, Katowice, Poland
- Silesian Centre for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41–500, Chorzow, Poland
| | - Barbara Kremer
- Institute of Paleobiology, Polish Academy of Science, Twarda 51/55, 00–818, Warszawa, Poland
| | - Roman Pawlicki
- Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31–034, Kraków, Poland
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103
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Wei TB, Chen JF, Cheng XB, Li H, Lin Q, Yao H, Zhang YM. A novel functionalized pillar[5]arene for forming a fluorescent switch and a molecular keypad. RSC Adv 2016. [DOI: 10.1039/c6ra14899a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The sensing mechanism of the sensor PC5 to Fe3+.
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Affiliation(s)
- Tai-Bao Wei
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - Jin-Fa Chen
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - Xiao-Bin Cheng
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - Hui Li
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - Qi Lin
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - Hong Yao
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
| | - You-Ming Zhang
- Key Laboratory of Eco-Environment-Related Polymer Materials
- Ministry of Education of China
- Key Laboratory of Polymer Materials of Gansu Province
- College of Chemistry and Chemical Engineering
- Northwest Normal University
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104
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Shen BX, Qian Y. A novel triphenylamine-BODIPY dendron: click synthesis, near-infrared emission and a multi-channel chemodosimeter for Hg2+ and Fe3+. J Mater Chem B 2016; 4:7549-7559. [DOI: 10.1039/c6tb02469f] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel near-infrared emission triphenylamine-BODIPY dendron for Hg2+ and Fe3+ detection, fluorescent nanoparticle and living cell imaging.
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Affiliation(s)
- Bao-xing Shen
- School of Chemistry and Chemical Engineering
- Southeast University
- Nanjing 211189
- China
| | - Ying Qian
- School of Chemistry and Chemical Engineering
- Southeast University
- Nanjing 211189
- China
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105
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Tian Y, Cao H, Qiao Y, Liu X. Antimicrobial and osteogenic properties of iron-doped titanium. RSC Adv 2016. [DOI: 10.1039/c6ra08359e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Iron doped modification layer formed on titanium achieved antibacterial effect as well as bioactivity by regulating the production of ROS.
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Affiliation(s)
- Yaxin Tian
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Huiliang Cao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Yuqin Qiao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 200050
- People's Republic of China
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106
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Santhoshkumar S, Velmurugan K, Prabhu J, Radhakrishnan G, Nandhakumar R. A naphthalene derived Schiff base as a selective fluorescent probe for Fe2+. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2015.09.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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107
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Mei J, Leung NLC, Kwok RTK, Lam JWY, Tang BZ. Aggregation-Induced Emission: Together We Shine, United We Soar! Chem Rev 2015; 115:11718-940. [DOI: 10.1021/acs.chemrev.5b00263] [Citation(s) in RCA: 5139] [Impact Index Per Article: 571.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ju Mei
- HKUST-Shenzhen Research Institute, Hi-Tech
Park, Nanshan, Shenzhen 518057, China
- Department of Chemistry,
HKUST Jockey Club Institute for Advanced Study, Institute of Molecular
Functional Materials, Division of Biomedical Engineering, State Key
Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Nelson L. C. Leung
- HKUST-Shenzhen Research Institute, Hi-Tech
Park, Nanshan, Shenzhen 518057, China
- Department of Chemistry,
HKUST Jockey Club Institute for Advanced Study, Institute of Molecular
Functional Materials, Division of Biomedical Engineering, State Key
Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ryan T. K. Kwok
- HKUST-Shenzhen Research Institute, Hi-Tech
Park, Nanshan, Shenzhen 518057, China
- Department of Chemistry,
HKUST Jockey Club Institute for Advanced Study, Institute of Molecular
Functional Materials, Division of Biomedical Engineering, State Key
Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Jacky W. Y. Lam
- HKUST-Shenzhen Research Institute, Hi-Tech
Park, Nanshan, Shenzhen 518057, China
- Department of Chemistry,
HKUST Jockey Club Institute for Advanced Study, Institute of Molecular
Functional Materials, Division of Biomedical Engineering, State Key
Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ben Zhong Tang
- HKUST-Shenzhen Research Institute, Hi-Tech
Park, Nanshan, Shenzhen 518057, China
- Department of Chemistry,
HKUST Jockey Club Institute for Advanced Study, Institute of Molecular
Functional Materials, Division of Biomedical Engineering, State Key
Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Guangdong
Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State
Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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108
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Bruchet M, Melman A. Fabrication of patterned calcium cross-linked alginate hydrogel films and coatings through reductive cation exchange. Carbohydr Polym 2015; 131:57-64. [DOI: 10.1016/j.carbpol.2015.05.021] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 04/29/2015] [Accepted: 05/05/2015] [Indexed: 10/23/2022]
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109
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Saeidi I, Barfi B, Asghari A, Gharahbagh AA, Barfi A, Peyrovi M, Afsharzadeh M, Hojatinasab M. Ionic-liquid-based hollow-fiber liquid-phase microextraction method combined with hybrid artificial neural network-genetic algorithm for speciation and optimized determination of ferro and ferric in environmental water samples. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:631. [PMID: 26383736 DOI: 10.1007/s10661-015-4860-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
A novel and environmentally friendly ionic-liquid-based hollow-fiber liquid-phase microextraction method combined with a hybrid artificial neural network (ANN)-genetic algorithm (GA) strategy was developed for ferro and ferric ions speciation as model analytes. Different parameters such as type and volume of extraction solvent, amounts of chelating agent, volume and pH of sample, ionic strength, stirring rate, and extraction time were investigated. Much more effective parameters were firstly examined based on one-variable-at-a-time design, and obtained results were used to construct an independent model for each parameter. The models were then applied to achieve the best and minimum numbers of candidate points as inputs for the ANN process. The maximum extraction efficiencies were achieved after 9 min using 22.0 μL of 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) as the acceptor phase and 10 mL of sample at pH = 7.0 containing 64.0 μg L(-1) of benzohydroxamic acid (BHA) as the complexing agent, after the GA process. Once optimized, analytical performance of the method was studied in terms of linearity (1.3-316 μg L(-1), R (2) = 0.999), accuracy (recovery = 90.1-92.3%), and precision (relative standard deviation (RSD) <3.1). Finally, the method was successfully applied to speciate the iron species in the environmental and wastewater samples.
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Affiliation(s)
- Iman Saeidi
- Iranian National Standards Organization, Khorasan-e-Razavi, Mashhad, Iran
| | - Behruz Barfi
- Department of Chemistry, Semnan University, Semnan, 35195-363, Iran.
| | - Alireza Asghari
- Department of Chemistry, Semnan University, Semnan, 35195-363, Iran
| | - Abdorreza Alavi Gharahbagh
- Department of Electrical and Computer Engineering, Islamic Azad University, Shahrood Branch, Shahrood, Iran
| | - Azadeh Barfi
- Department of Biology, School of Science, Isfahan Payam-e Noor University, Isfahan, Iran
| | - Moazameh Peyrovi
- Department of Chemistry, University of Mazandaran, Babolsar, Iran
| | - Maryam Afsharzadeh
- Department of Research and Development of Samen Pharmaceutical Company, Mashhad, Iran
| | - Mostafa Hojatinasab
- Department of Research and Development of Samen Pharmaceutical Company, Mashhad, Iran
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110
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Xuan W, Pan R, Wei Y, Cao Y, Li H, Liang FS, Liu KJ, Wang W. Reaction-Based “Off–On” Fluorescent Probe Enabling Detection of Endogenous Labile Fe2+ and Imaging of Zn2+-induced Fe2+ Flux in Living Cells and Elevated Fe2+ in Ischemic Stroke. Bioconjug Chem 2015; 27:302-8. [DOI: 10.1021/acs.bioconjchem.5b00259] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Weimin Xuan
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Rong Pan
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Yongyi Wei
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Yanting Cao
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Huanqiu Li
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
- College
of Pharmaceutical Science, Soochow University, Suzhou 215123, P. R. China
| | - Fu-Sen Liang
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Ke-Jian Liu
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Wei Wang
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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111
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Iron management and production of electricity by microorganisms. Appl Microbiol Biotechnol 2015; 99:8329-36. [DOI: 10.1007/s00253-015-6897-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/27/2015] [Accepted: 07/30/2015] [Indexed: 10/23/2022]
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112
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Niwa M, Hirayama T, Okuda K, Nagasawa H. A new class of high-contrast Fe(II) selective fluorescent probes based on spirocyclized scaffolds for visualization of intracellular labile iron delivered by transferrin. Org Biomol Chem 2015; 12:6590-7. [PMID: 24953684 DOI: 10.1039/c4ob00935e] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Iron is an essential metal nutrient that plays physiologically and pathologically important roles in biological systems. However, studies on the trafficking, storage, and functions of iron itself in living samples have remained challenging due to the lack of efficient methods for monitoring labile intracellular iron. Herein, we report a new class of Fe(2+)-selective fluorescent probes based on the spirocyclization of hydroxymethylrhodamine and hydroxymethylrhodol scaffolds controlled by using our recently established N-oxide chemistry as a Fe(2+)-selective switch of fluorescence response. By suppressing the background signal, the spirocyclization strategy improved the turn-on rate dramatically, and reducing the size of the substituents of the N-oxide group enhanced the reaction rate against Fe(2+), compared with the first generation N-oxide based Fe(2+) probe, RhoNox-1. These new probes showed significant enhancements in the fluorescence signal against not only the exogenously loaded Fe(2+) but also the endogenous Fe(2+) levels. Furthermore, we succeeded in monitoring the accumulation of labile iron in the lysosome induced by transferrin-mediated endocytosis with a turn-on fluorescence response.
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Affiliation(s)
- Masato Niwa
- Laboratory of Pharmaceutical & Medicinal Chemistry, Gifu Pharmaceutical University, 1-25-4, Daigakunishi, Gifu, Japan.
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113
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Kanaujia PK, Bajaj P, Kumar S, Singhal N, Virdi JS. Proteomic analysis of Yersinia enterocolitica biovar 1A under iron-rich and iron-poor conditions indicate existence of efficiently regulated mechanisms of iron homeostasis. J Proteomics 2015; 124:39-49. [PMID: 25913300 DOI: 10.1016/j.jprot.2015.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 03/30/2015] [Accepted: 04/13/2015] [Indexed: 01/30/2023]
Abstract
UNLABELLED The pathogenicity of Yersinia enterocolitica biovar 1A strains is controversial as these lack most of the known virulence factors. Acquisition of iron and presence of well-regulated iron homeostasis in bacteria represents an important virulence trait. Differential abundance of proteins was examined under iron-rich and iron-poor conditions in a clinical Y. enterocolitica biovar 1A strain IP27407. Whole cell protein profiles were analysed by 2D gel electrophoresis (2D-GE). Following statistical and MALDI-TOF MS analyses, 28 differentially abundant proteins were identified. Significant iron-responsive changes were observed in the proteins involved in iron acquisition or storage namely, hemin receptor (HemR), periplasmic Fe(2+) transport protein (Tpd), periplasmic chelated iron-binding protein (YfeA) and bacterioferritin (Bfr). Quantitative real-time PCR (qRT-PCR) of eight mRNA transcripts revalidated the differential protein abundance. In silico analysis of iron homeostasis mediated by the bacterioferritin and bacterioferritin-associated ferredoxin (Bfr-Bfd) complex suggested two pathways for the release of reserve iron which might be operating under conditions of different iron availability. The study, for the first time, showed the existence of highly competent iron homeostasis mechanisms in Y. enterocolitica biovar 1A and identified the key proteins involved thereof. Such mechanisms might have implications for the pathogenicity of Y. enterocolitica biovar 1A strains. BIOLOGICAL SIGNIFICANCE Although, a few studies have identified the differentially abundant bacterial proteins in response to iron starvation, little information is available in this regard for Y. enterocolitica (especially, the biovar 1A strains). In the present study, differential abundance of several proteins was identified under iron-rich and iron-poor conditions by 2D-GE and MALDI-TOF/MS analysis. These included proteins which may not only be directly implicated in iron acquisition or storage but also play crucial role in cellular metabolism. Given the absence of most known virulence factors in Y. enterocolitica biovar 1A strains, demonstration of well-regulated mechanisms for efficient iron homeostasis constitutes an important observation. The proteins, as identified in the present study, provide useful insights to further unravel the potential pathogenicity of the biovar 1A strains.
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Affiliation(s)
- Pawan Kumar Kanaujia
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
| | - Priyanka Bajaj
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
| | - Shakti Kumar
- Parasitology Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793022, India.
| | - Neelja Singhal
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
| | - Jugsharan Singh Virdi
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
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114
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El-Gendy N, Qian J, Eshelman K, Rivera M, Berkland C. Antibiotic activity of iron-sequestering polymers. Biomacromolecules 2015; 16:1480-8. [PMID: 25872681 DOI: 10.1021/bm5016392] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Increasing antibiotic resistance has compelled the development of novel antibiotics and adjuvant therapies that enhance the efficacy of existing antibiotics. Iron plays a critical role in bacterial infections, yet the use of iron chelators as adjuvant therapy with antibiotics has yielded highly variable outcomes. Multivalent polymeric materials offer an alternative approach to bind and sequester iron via high avidity interactions. Here, a biomimetic iron-sequestering polymer (PAI-DHBA) was synthesized by modifying side chains of cross-linked polyallylamine (cPAI) with 2,3-dihydroxybenzoic acid (DHBA). PAI-DHBA polymer gels with various DHBA contents showed high iron affinity indices and high selectivity for iron. The polymers showed mild antibiotic properties when used to treat established bacterial cultures. Pretreating culture media with PAI-DHBA polymer, however, removed all detectable iron from media and effectively inhibited the growth of Pseudomonas aeruginosa. In addition, bacterial growth was more susceptible to antibiotics combined with PAI-DHBA. Multivalent polymers that bind and sequester iron, such as PAI-DHBA, offer a promising early intervention or adjuvant to antibiotics.
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Affiliation(s)
- Nashwa El-Gendy
- ∥Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | | | | | | | - Cory Berkland
- §Department of Chemical and Petroleum Engineering, The University of Kansas, Learned Hall, 1530 West 15th, Lawrence, Kansas 66045, United States
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115
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Cheng HR, Qian Y. A novel BODIPY-Schiff base-based colorimetric and fluorometric dosimeter for Hg2+, Fe3+ and Au3+. RSC Adv 2015. [DOI: 10.1039/c5ra15546k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
A simple Schiff base-based multi-targets dosimeter for Hg2+, Fe3+ and Au3+ has been reported.
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Affiliation(s)
- Huan-ren Cheng
- School of Chemistry and Chemical Engineering
- Southeast University
- Nanjing
- China
| | - Ying Qian
- School of Chemistry and Chemical Engineering
- Southeast University
- Nanjing
- China
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116
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Dong L, Sun Y, Zhang C, Han D, Bai Y, Chen M. Efficient CO2 capture by metallo-supramolecular polymers as fillers to fabricate a polymeric blend membrane. RSC Adv 2015. [DOI: 10.1039/c5ra12913c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Novel fillers based on metallo-supramolecular polymers were incorporated into PEBA2533 to obtain blend membranes, showing excellent CO2 permeability and CO2/N2 selectivity.
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Affiliation(s)
- Liangliang Dong
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
| | - Yuping Sun
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
| | - Chunfang Zhang
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
| | - Dan Han
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
| | - Yunxiang Bai
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
| | - Mingqing Chen
- Key Laboratory of Food Colloids and Biotechnology
- Ministry of Education
- School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
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117
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Haslinger S, Lindhorst AC, Kück JW, Cokoja M, Pöthig A, Kühn FE. Isocyanide substitution reactions at the trans labile sites of an iron(ii) N-heterocyclic carbene complex. RSC Adv 2015. [DOI: 10.1039/c5ra18270k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A variety of isocyanide-substituted Fe(ii) N-heterocyclic carbene (NHC) complexes has been synthesized, starting from an Fe(ii) NHC complex with an equatorial, tetradentate bis(pyridyl-NHC) ligand (NCCN).
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Affiliation(s)
- S. Haslinger
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
| | - A. C. Lindhorst
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
| | - J. W. Kück
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
| | - M. Cokoja
- Chair of Inorganic and Organometallic Chemistry
- Technische Universität München (TUM)
- D-85747 Garching bei München
- Germany
| | - A. Pöthig
- Catalysis Research Center
- Technische Universität München (TUM)
- D-85747 Garching bei München
- Germany
| | - F. E. Kühn
- Chair of Inorganic Chemistry/Molecular Catalysis
- Technische Universität München (TUM)
- Department of Chemistry/Catalysis Research Center
- D-85747 Garching bei München
- Germany
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118
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Kumar P, Kumar V, Gupta R. Arene-based fluorescent probes for the selective detection of iron. RSC Adv 2015. [DOI: 10.1039/c5ra20760f] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Amide based probes containing phenyl (L1), naphthyl (L2) and anthracenyl (L3) groups were screened towards metal ions. Probes L2 and L3 display sensing for Fe2+ and Fe3+ ions. The L3–Fe3+ system is shown to have potential applications in logic gates and cell imaging.
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Affiliation(s)
- Pramod Kumar
- Department of Chemistry
- University of Delhi
- Delhi-110007
- India
| | - Vijay Kumar
- Department of Chemistry
- University of Delhi
- Delhi-110007
- India
| | - Rajeev Gupta
- Department of Chemistry
- University of Delhi
- Delhi-110007
- India
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119
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Buer B, Paul B, Das D, Stuckey JA, Marsh ENG. Insights into substrate and metal binding from the crystal structure of cyanobacterial aldehyde deformylating oxygenase with substrate bound. ACS Chem Biol 2014; 9:2584-93. [PMID: 25222710 PMCID: PMC4245163 DOI: 10.1021/cb500343j] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/02/2014] [Indexed: 11/28/2022]
Abstract
The nonheme diiron enzyme cyanobacterial aldehyde deformylating oxygenase, cADO, catalyzes the highly unusual deformylation of aliphatic aldehydes to alkanes and formate. We have determined crystal structures for the enzyme with a long-chain water-soluble aldehyde and medium-chain carboxylic acid bound to the active site. These structures delineate a hydrophobic channel that connects the solvent with the deeply buried active site and reveal a mode of substrate binding that is different from previously determined structures with long-chain fatty acids bound. The structures also identify a water channel leading to the active site that could facilitate the entry of protons required in the reaction. NMR studies examining 1-[(13)C]-octanal binding to cADO indicate that the enzyme binds the aldehyde form rather than the hydrated form. Lastly, the fortuitous cocrystallization of the metal-free form of the protein with aldehyde bound has revealed protein conformation changes that are involved in binding iron.
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Affiliation(s)
- Benjamin
C. Buer
- Department of Chemistry, Life Sciences Institute, and Department of Biological
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Bishwajit Paul
- Department of Chemistry, Life Sciences Institute, and Department of Biological
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Debasis Das
- Department of Chemistry, Life Sciences Institute, and Department of Biological
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jeanne A. Stuckey
- Department of Chemistry, Life Sciences Institute, and Department of Biological
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - E. Neil G. Marsh
- Department of Chemistry, Life Sciences Institute, and Department of Biological
Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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120
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Gu Z, Lei W, Shi W, Hao Q, Si W, Xia X, Wang F. Studies on the interaction between 9-fluorenylmethyl chloroformate and Fe3+ and Cu2+ ions: spectroscopic and theoretical calculation approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 132:361-368. [PMID: 24887497 DOI: 10.1016/j.saa.2014.05.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 05/12/2014] [Indexed: 06/03/2023]
Abstract
The interaction between 9-fluorenylmethyl chloroformate (FMOC-Cl) and Fe3+ and Cu2+ ions was investigated using fluorescence, UV/Vis absorption spectroscopies and theoretical calculation. The optical property of FMOC-Cl was studied in detail in absence and presence of various transition metal ions with particular affinity to Fe3+ and Cu2+ ions. With the fluorescence characteristic band centered at 307 and 315 nm for FMOC-Cl, the introduction of Fe3+ or Cu2+ ions leads to the fluorescence quenching of FMOC-Cl with different shift and intensities of two fluorescent bands. It allows us to differentiate between FMOC-Cl and Fe3+ and Cu2+ ions interaction behavior. The study on fluorescent kinetics confirms that the fluorescence quenching of FMOC-Cl with Fe3+ and Cu2+ ions is based on the formation of non-fluorescent material, that is, static quenching. Further analyses of bond lengths, Mulliken atomic charges and the frontier orbital compositions for FMOC-Cl and its complexes with Fe3+ and Cu2+ ions were carried out. The theoretical calculations prove the fluorescence quenching originates from the formation of coordination bonds between the oxygen atom of the carbonyl group of FMOC-Cl and Fe3+ and Cu2+ ions. The commercially available FMOC-Cl can be used as excellent fluorescent probe toward Fe3+ and Cu2+ ions with high sensitivity.
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Affiliation(s)
- Zhenyan Gu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Wu Lei
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Wenyan Shi
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Qingli Hao
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Weimeng Si
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Xifeng Xia
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Fengxiang Wang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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121
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Ishimori K, Watanabe Y. Unique Heme Environmental Structures in Heme-regulated Proteins Using Heme as the Signaling Molecule. CHEM LETT 2014. [DOI: 10.1246/cl.140787] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | - Yuta Watanabe
- Department of Chemistry, Faculty of Science, Hokkaido University
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122
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Sui B, Tang S, Liu T, Kim B, Belfield KD. Novel BODIPY-based fluorescence turn-on sensor for Fe3+ and its bioimaging application in living cells. ACS APPLIED MATERIALS & INTERFACES 2014; 6:18408-18412. [PMID: 25337695 DOI: 10.1021/am506262u] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A novel boron-dipyrromethene (BODIPY) based fluorescence turn-on sensor for detecting Fe(3+) in aqueous media is reported with 23-fold fluorescence enhancement. The sensor is comprised of a combination of BODIPY fluorophore and a new Fe(3+)-recognizing cryptand that exhibits high selectivity, sensitivity, and reversibility toward Fe(3+) detection. Cell imaging studies demonstrate that this sensor is capable of sensing Fe(3+) in living cells.
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Affiliation(s)
- Binglin Sui
- Department of Chemistry and ‡CREOL, The College of Optics and Photonics, University of Central Florida , Orlando, Florida 32816, United States
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123
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Antibacterial activity and cytocompatibility of titanium oxide coating modified by iron ion implantation. Acta Biomater 2014; 10:4505-17. [PMID: 24914826 DOI: 10.1016/j.actbio.2014.06.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 05/31/2014] [Accepted: 06/01/2014] [Indexed: 11/20/2022]
Abstract
In this work, zero valent iron nanoparticles (Fezero-NPs) and iron oxide nanoparticles (Feox-NPs) were synthesized at the subsurface and surface regions of titanium oxide coatings (TOCs) by plasma immersion ion implantation. This novel Fe-NPs/TOC system showed negligible iron releasing, great electron storage capability and excellent cytocompatibility in vitro. Importantly, the system showed selective antibacterial ability which can kill Staphylococcus aureus under dark conditions but has no obvious antibacterial effect against Escherichia coli. Owing to a bipolar Schottky barrier between Fezero-NPs/TOC and Fezero-NPs/Feox-NPs, electrons could be captured by the Fezero-NPs bounded at the subsurface region of the coating. This electron storage capability of the Fe-NPs/TOC system induced extracellular electron transportation and accumulation of adequate valence-band holes (h(+)) at the external side, which caused oxidation damage to S. aureus cells in the dark. No obvious biocide effect against E. coli resulted from lack of electron transfer ability between E. coli and substrate materials. This work may open up a novel and controlled strategy to design coatings of implants with antibacterial ability and cytocompatibility for medical applications.
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124
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Theil EC. IRE mRNA riboregulators use metabolic iron (Fe(2+)) to control mRNA activity and iron chemistry in animals. Metallomics 2014; 7:15-24. [PMID: 25209685 DOI: 10.1039/c4mt00136b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A family of noncoding RNAs bind Fe(2+) to increase protein synthesis. The structures occur in messenger RNAs encoding animal proteins for iron metabolism. Each mRNA regulatory sequence, ∼30 ribonucleotides long, is called an IRE (Iron Responsive Element), and folds into a bent, A-RNA helix with a terminal loop. Riboregulatory RNAs, like t-RNAs, r-RNAs micro-RNAs, etc. contrast with DNA, since single-stranded RNA can fold into a variety of complex, three-dimensional structures. IRE-RNAs bind two types of proteins: (1) IRPs which are protein repressors, sequence-related to mitochondrial aconitases. (2) eIF-4F, which bind ribosomes and enhances general protein biosynthesis. The competition between IRP and eIF-4F binding to IRE-RNA is controlled by Fe(2+)-induced changes in the IRE-RNA conformation. Mn(2+), which also binds to IRE-RNA in solution, is a convenient experimental proxy for air-sensitive Fe(2+) studies of in vitro protein biosynthesis and protein binding. However, only Fe(2+) has physiological effects on protein biosynthesis directed by IRE-mRNAs. The structures of the IRE-RNA riboregulators is known indirectly from effects of base substitutions on function, from solution NMR of the free RNA, and of X-ray crystallography of the IRE-RNA-IRP repressor complex. However, the inability to date, to crystallize the free IRE-RNA, and the dissociation of the IRE-RNA-IRP complex when metal binds, have hampered direct identification and characterization of the RNA-metal binding sites. The high conservation of the primary sequence in IRE-mRNA control elements has facilitated their identification and analysis of metal-assisted riboregulator function. Expansion of RNA search analyses beyond primary will likely reveal other, metal-dependent families of mRNA riboregulators.
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Affiliation(s)
- Elizabeth C Theil
- The Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA.
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125
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Iron-rich ferritin in the hypoxia-tolerant rodent Spalax ehrenbergi: a naturally-occurring biomarker confirms the internalization and pathways of intracellular macromolecules. J Struct Biol 2014; 187:254-265. [PMID: 25050761 DOI: 10.1016/j.jsb.2014.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 06/20/2014] [Accepted: 07/11/2014] [Indexed: 02/08/2023]
Abstract
The discovery of pits/caveolae in the plasmalemma advanced the study of macromolecule internalization. "Transcytosis" describes the transport of macromolecular cargo from one front of a polarized cell to the other within membrane-bounded carrier(s), via endocytosis, intracellular trafficking and exocytosis. Clathrin-mediated transcytosis is used extensively by epithelial cells, while caveolae-mediated transcytosis mostly occurs in endothelial cells. The internalization pathways were monitored by various markers, including radioisotopes, nanoparticles, enzymes, immunostains, and fluorophores. We describe an internalization pathway identified using a naturally-occurring biomarker, in vivo assembled ferritin, containing electron-dense iron cores. Iron, an essential trace metal for most living species and iron homeostasis, is crucial for cellular life. Ferritin is a ubiquitous and highly conserved archeoprotein whose main function is to store a reserve iron supply inside the cytoplasm in a non-toxic form. Ferritin is present in all organisms which have a metabolic requirement for iron and in even in organisms whose taxonomic rank is very low. The newborns of the blind mole, Spalax ehrenbergi, are born and live in a hypoxic environment and have significant iron overload in their liver and heart, but their iron metabolism has not been previously studied. These newborns, which are evolutionarily adapted to fluctuations in the environmental oxygen, have a unique ability to sequester transplacental iron and store it in ferritin without any signs of iron toxicity. Using the ferrihydrite cores of ferritin, we were able to monitor the ferritin internalization from portals of its entry into the cytosol of hepatocytes and cardiomyocytes and into the lysosomes.
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126
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Novel role of the Candida albicans ferric reductase gene CFL1 in iron acquisition, oxidative stress tolerance, morphogenesis and virulence. Res Microbiol 2014; 165:252-61. [PMID: 24631590 DOI: 10.1016/j.resmic.2014.03.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 03/02/2014] [Indexed: 01/28/2023]
Abstract
Ferric reductase catalyzes the reduction of ferric iron into ferrous iron and plays an essential role in high-affinity iron acquisition. In this study, we found that the cfl1Δ/Δ (orf19.1263) mutant was not defective in iron acquisition. However, deletion of CFL1 increased cellular iron accumulation by elevating surface ferric reductase activity in Candida albicans, revealing that there existed functional redundancy and/or a compensatory upregulation mechanism among ferric reductase genes. The absence of CFL1 resulted in increased expression levels of other alternative ferric reductase genes, including FRP1, CFL2 and FRE10. In addition, CFL1 played an important role in the response to different oxidative stresses. Further research revealed that the cfl1Δ/Δ mutant exhibited higher levels of both ROS production and SOD activity under oxidative conditions. Moreover, deletion of CFL1 led to a profound defect in filamentous development in an iron-independent manner at both 30 and 37 °C. The cfl1Δ/Δ mutant exhibited highly attenuated virulence and reduced fungal burdens in the mouse systemic infection model, indicating that CFL1 might be a potential target for antifungal drug development. In summary, our results provide new insights into the roles of ferric reductase gene in C. albicans.
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127
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Zhang Y, Li X, Gao L, Qiu J, Heng L, Tang BZ, Jiang L. Silole-Infiltrated Photonic Crystal Films as Effective Fluorescence Sensor for Fe3+and Hg2+. Chemphyschem 2014; 15:507-13. [DOI: 10.1002/cphc.201300949] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/18/2013] [Indexed: 11/08/2022]
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128
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Schweitzer MH, Zheng W, Cleland TP, Goodwin MB, Boatman E, Theil E, Marcus MA, Fakra SC. A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time. Proc Biol Sci 2014; 281:20132741. [PMID: 24285202 PMCID: PMC3866414 DOI: 10.1098/rspb.2013.2741] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 10/29/2013] [Indexed: 01/15/2023] Open
Abstract
The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-αFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25°C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O2 > HB - O2 > -O2 >> +O2. The well-known O2/haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O2/haeme interactions in the preservation of fossil soft tissues.
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Affiliation(s)
- Mary H. Schweitzer
- Marine, Earth, and Atmospheric Sciences, North Carolina State University, Campus Box 8208, Raleigh, NC 27695, USA
- North Carolina Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC 27601, USA
| | - Wenxia Zheng
- Marine, Earth, and Atmospheric Sciences, North Carolina State University, Campus Box 8208, Raleigh, NC 27695, USA
| | - Timothy P. Cleland
- Marine, Earth, and Atmospheric Sciences, North Carolina State University, Campus Box 8208, Raleigh, NC 27695, USA
| | - Mark B. Goodwin
- Museum of Paleontology, University of California, Berkeley, CA 94720, USA
| | - Elizabeth Boatman
- Department of Material Sciences and Engineering, University of California, Berkeley, CA 94720, USA
| | - Elizabeth Theil
- CHORI (Children's Hospital Oakland Research Institute), 5700 Martin Luther King, Jr. Way, Oakland, CA 94609, USA
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
| | - Matthew A. Marcus
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Sirine C. Fakra
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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129
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Abstract
At the center of iron and oxidant metabolism is the ferritin superfamily: protein cages with Fe(2+) ion channels and two catalytic Fe/O redox centers that initiate the formation of caged Fe2O3·H2O. Ferritin nanominerals, initiated within the protein cage, grow inside the cage cavity (5 or 8 nm in diameter). Ferritins contribute to normal iron flow, maintenance of iron concentrates for iron cofactor syntheses, sequestration of iron from invading pathogens, oxidant protection, oxidative stress recovery, and, in diseases where iron accumulates excessively, iron chelation strategies. In eukaryotic ferritins, biomineral order/crystallinity is influenced by nucleation channels between active sites and the mineral growth cavity. Animal ferritin cages contain, uniquely, mixtures of catalytically active (H) and inactive (L) polypeptide subunits with varied rates of Fe(2+)/O2 catalysis and mineral crystallinity. The relatively low mineral order in liver ferritin, for example, coincides with a high percentage of L subunits and, thus, a low percentage of catalytic sites and nucleation channels. Low mineral order facilitates rapid iron turnover and the physiological role of liver ferritin as a general iron source for other tissues. Here, current concepts of ferritin structure/function/genetic regulation are discussed and related to possible therapeutic targets such as mini-ferritin/Dps protein active sites (selective pathogen inhibition in infection), nanocage pores (iron chelation in therapeutic hypertransfusion), mRNA noncoding, IRE riboregulator (normalizing the ferritin iron content after therapeutic hypertransfusion), and protein nanovessels to deliver medicinal or sensor cargo.
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Affiliation(s)
- Elizabeth C Theil
- Children's Hospital Oakland Research Institute (CHORI) , 5700 Martin Luther King Jr. Way, Oakland, California 94609, United States , and Department of Molecular and Structural Biochemistry, North Carolina State University , Raleigh, North Carolina 2765-7622, United States
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130
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Au-Yeung HY, Chan J, Chantarojsiri T, Chang CJ. Molecular imaging of labile iron(II) pools in living cells with a turn-on fluorescent probe. J Am Chem Soc 2013; 135:15165-73. [PMID: 24063668 DOI: 10.1021/ja4072964] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Iron is an essential metal for living organisms, but misregulation of its homeostasis at the cellular level can trigger detrimental oxidative and/or nitrosative stress and damage events. Motivated to help study the physiological and pathological consequences of biological iron regulation, we now report a reaction-based strategy for monitoring labile Fe(2+) pools in aqueous solution and living cells. Iron Probe 1 (IP1) exploits a bioinspired, iron-mediated oxidative C-O bond cleavage reaction to achieve a selective turn-on response to Fe(2+) over a range of cellular metal ions in their bioavailable forms. We show that this first-generation chemical tool for fluorescence Fe(2+) detection can visualize changes in exchangeable iron stores in living cells upon iron supplementation or depletion, including labile iron pools at endogenous, basal levels. Moreover, IP1 can be used to identify reversible expansion of labile iron pools by stimulation with vitamin C or the iron regulatory hormone hepcidin, providing a starting point for further investigations of iron signaling and stress events in living systems as well as future probe development.
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Affiliation(s)
- Ho Yu Au-Yeung
- Departments of Chemistry and ‡Molecular and Cell Biology and §Howard Hughes Medical Institute, University of California , Berkeley, California 94720, United States
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131
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Lawen A, Lane DJR. Mammalian iron homeostasis in health and disease: uptake, storage, transport, and molecular mechanisms of action. Antioxid Redox Signal 2013. [PMID: 23199217 DOI: 10.1089/ars.2011.4271] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron is a crucial factor for life. However, it also has the potential to cause the formation of noxious free radicals. These double-edged sword characteristics demand a tight regulation of cellular iron metabolism. In this review, we discuss the various pathways of cellular iron uptake, cellular iron storage, and transport. Recent advances in understanding the reduction and uptake of non-transferrin-bound iron are discussed. We also discuss the recent progress in the understanding of transcriptional and translational regulation by iron. Furthermore, we discuss recent advances in the understanding of the regulation of cellular and systemic iron homeostasis and several key diseases resulting from iron deficiency and overload. We also discuss the knockout mice available for studying iron metabolism and the related human conditions.
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Affiliation(s)
- Alfons Lawen
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Melbourne, Australia.
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132
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Xu N, Cheng X, Yu Q, Qian K, Ding X, Liu R, Zhang B, Xing L, Li M. Aft2, a novel transcription regulator, is required for iron metabolism, oxidative stress, surface adhesion and hyphal development in Candida albicans. PLoS One 2013; 8:e62367. [PMID: 23626810 PMCID: PMC3633901 DOI: 10.1371/journal.pone.0062367] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 03/20/2013] [Indexed: 12/11/2022] Open
Abstract
Morphological transition and iron metabolism are closely relevant to Candida albicans pathogenicity and virulence. In our previous study, we demonstrated that C. albicans Aft2 plays an important role in ferric reductase activity and virulence. Here, we further explored the roles of C. albicans Aft2 in numerous cellular processes. We found that C. albicans Aft2 exhibited an important role in iron metabolism through bi-directional regulation effects on iron-regulon expression. Deletion of AFT2 reduced cellular iron accumulation under iron-deficient conditions. Furthermore, both reactive oxygen species (ROS) generation and superoxide dismutase (SOD) activity were remarkably increased in the aft2Δ/Δ mutant, which were thought to be responsible for the defective responses to oxidative stress. However, we found that over-expression of C. albicans AFT2 under the regulation of the strong PGK1 promoter could not effectively rescue Saccharomyces cerevisiae aft1Δ mutant defects in some cellular processes, such as cell-wall assembly, ion homeostasis and alkaline resistance, suggesting a possibility that C. albicans Aft2 weakened its functional role of regulating some cellular metabolism during the evolutionary process. Interestingly, deletion of AFT2 in C. albicans increased cell surface hydrophobicity, cell flocculation and the ability of adhesion to polystyrene surfaces. In addition, our results also revealed that C. albicans Aft2 played a dual role in regulating hypha-specific genes under solid and liquid hyphal inducing conditions. Deletion of AFT2 caused an impaired invasive growth in solid medium, but an increased filamentous aggregation and growth in liquid conditions. Moreover, iron deficiency and environmental cues induced nuclear import of Aft2, providing additional evidence for the roles of Aft2 in transcriptional regulation.
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Affiliation(s)
- Ning Xu
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Xinxin Cheng
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Kefan Qian
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaohui Ding
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Ruming Liu
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Biao Zhang
- Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Laijun Xing
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology for Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
- * E-mail:
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133
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Chen WD, Gong WT, Ye ZQ, Lin Y, Ning GL. FRET-based ratiometric fluorescent probes for selective Fe3+ sensing and their applications in mitochondria. Dalton Trans 2013; 42:10093-6. [DOI: 10.1039/c3dt50832c] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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134
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Zappa S, Bauer CE. Iron homeostasis in the Rhodobacter genus. ADVANCES IN BOTANICAL RESEARCH 2013; 66:10.1016/B978-0-12-397923-0.00010-2. [PMID: 24382933 PMCID: PMC3875232 DOI: 10.1016/b978-0-12-397923-0.00010-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Metals are utilized for a variety of critical cellular functions and are essential for survival. However cells are faced with the conundrum of needing metals coupled with e fact that some metals, iron in particular are toxic if present in excess. Maintaining metal homeostasis is therefore of critical importance to cells. In this review we have systematically analyzed sequenced genomes of three members of the Rhodobacter genus, R. capsulatus SB1003, R. sphaeroides 2.4.1 and R. ferroxidans SW2 to determine how these species undertake iron homeostasis. We focused our analysis on elemental ferrous and ferric iron uptake genes as well as genes involved in the utilization of iron from heme. We also discuss how Rhodobacter species manage iron toxicity through export and sequestration of iron. Finally we discuss the various putative strategies set up by these Rhodobacter species to regulate iron homeostasis and the potential novel means of regulation. Overall, this genomic analysis highlights surprisingly diverse features involved in iron homeostasis in the Rhodobacter genus.
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Affiliation(s)
- Sébastien Zappa
- Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall, 212 S Hawthorne Dr, Bloomington, IN 47405, U. S. A
| | - Carl E. Bauer
- Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall, 212 S Hawthorne Dr, Bloomington, IN 47405, U. S. A
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135
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Wysokinski D, Danisz K, Blasiak J, Dorecka M, Romaniuk D, Szaflik J, Szaflik JP. An association of transferrin gene polymorphism and serum transferrin levels with age-related macular degeneration. Exp Eye Res 2013; 106:14-23. [DOI: 10.1016/j.exer.2012.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 09/18/2012] [Accepted: 10/08/2012] [Indexed: 12/16/2022]
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136
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Xu H, Liu Z, Sheng L, Chen M, Huang D, Zhang H, Song C, Chen S. A novel “turn-on” fluorescent probe for Fe3+in aqueous media based on CN isomerization. NEW J CHEM 2013. [DOI: 10.1039/c2nj40767a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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137
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An efficient and selective flourescent chemical sensor based on 5-(8-hydroxy-2-quinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane as a new fluoroionophore for determination of iron(III) ions. A novel probe for iron speciation. Anal Chim Acta 2012; 761:169-77. [PMID: 23312328 DOI: 10.1016/j.aca.2012.11.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 11/13/2012] [Accepted: 11/16/2012] [Indexed: 11/20/2022]
Abstract
A novel fluorescent chemical sensor for the highly sensitive and selective determination of Fe(3+) ions in aqueous solutions is prepared. The iron sensing system was prepared by incorporating 5-(8-hydroxy-2-quinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L) as a neutral Fe(3+)-selective fluoroionophore in the plasticized PVC membrane containing sodium tetraphenylborate as a liphophilic anionic additive. The response of the sensor is based on the strong fluorescence quenching of L by Fe(3+) ions. At pH 5.5, the proposed sensor displays a calibration curve over a wide concentration range from 6.0 × 10(-4) to 1.0 × 10(-7) M, with a relatively fast response time of less than 2 min. In addition to a high stability and reproducibility, the sensor shows a unique selectivity toward Fe(3+) ion with respect to common coexisting cations. The proposed fluorescence optode was applied to the determination of iron(III) content of straw of rice, spinach and different water samples. The fluorescent sensor was also used as a novel probe for Fe(3+)/Fe(2+) speciation in aqueous solution.
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138
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The reactivity of macrocyclic Fe(II) paraCEST MRI contrast agents towards biologically relevant anions, cations, oxygen or peroxide. J Inorg Biochem 2012; 117:212-9. [DOI: 10.1016/j.jinorgbio.2012.06.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 06/08/2012] [Accepted: 06/10/2012] [Indexed: 01/10/2023]
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139
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Catalán V, Gómez-Ambrosi J, Rodríguez A, Ramírez B, Rotellar F, Valentí V, Silva C, Gil MJ, Salvador J, Frühbeck G. Six-transmembrane epithelial antigen of prostate 4 and neutrophil gelatinase-associated lipocalin expression in visceral adipose tissue is related to iron status and inflammation in human obesity. Eur J Nutr 2012. [PMID: 23179203 DOI: 10.1007/s00394-012-0464-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE Six-transmembrane epithelial antigen of prostate (STEAP)-4 and neutrophil gelatinase-associated lipocalin (NGAL) are novel adipokines related to iron homeostasis with potential roles in insulin resistance and inflammation. The aim of the present work was to evaluate the effect of obesity and iron status on gene expression levels of STEAP-4 and NGAL in visceral adipose tissue (VAT) and its implication in inflammation. METHODS VAT biopsies obtained from 53 subjects were used in the study. Real-time PCR and Western-blot were performed to quantify the levels of STEAP4 and NGAL in VAT as well as the association with other genes implicated in inflammatory pathways. Circulating ferritin and free iron concentrations were also determined. RESULTS Obese patients exhibited significantly increased STEAP4 and NGAL mRNA expression levels (P < 0.001) compared to lean subjects. Protein expression levels of NGAL (P < 0.05) and STEAP4 were also higher in the visceral fat depot of obese patients, although protein levels of STEAP4 did not reach statistical significance. A negative correlation (P < 0.05) between free iron concentrations and gene expression levels of both STEAP4 and NGAL was found, while circulating ferritin concentrations were positively correlated (P < 0.05) with NGAL mRNA after body fat (BF) adjustment. Furthermore, a significant positive association between STEAP4 and NGAL gene expression levels with inflammatory markers was also detected (P < 0.01). CONCLUSION These findings represent the first observation that STEAP4 and NGAL mRNA and protein levels in human VAT are related to iron status. Moreover, STEAP4 and NGAL are associated with pro-inflammatory markers suggesting their potential involvement in the low-grade chronic inflammation accompanying obesity.
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Affiliation(s)
- Victoria Catalán
- Metabolic Research Laboratory, Clínica Universidad de Navarra, Pamplona, Spain.
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140
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Li P, Xiao H, Tang B. A Near-infrared Fluorescent Probe for Selective Simultaneous Detection of Fe2+and Cl−in Living Cells. CHINESE J CHEM 2012. [DOI: 10.1002/cjoc.201200652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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141
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Lill R, Hoffmann B, Molik S, Pierik AJ, Rietzschel N, Stehling O, Uzarska MA, Webert H, Wilbrecht C, Mühlenhoff U. The role of mitochondria in cellular iron-sulfur protein biogenesis and iron metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1823:1491-508. [PMID: 22609301 DOI: 10.1016/j.bbamcr.2012.05.009] [Citation(s) in RCA: 364] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 12/21/2022]
Abstract
Mitochondria play a key role in iron metabolism in that they synthesize heme, assemble iron-sulfur (Fe/S) proteins, and participate in cellular iron regulation. Here, we review the latter two topics and their intimate connection. The mitochondrial Fe/S cluster (ISC) assembly machinery consists of 17 proteins that operate in three major steps of the maturation process. First, the cysteine desulfurase complex Nfs1-Isd11 as the sulfur donor cooperates with ferredoxin-ferredoxin reductase acting as an electron transfer chain, and frataxin to synthesize an [2Fe-2S] cluster on the scaffold protein Isu1. Second, the cluster is released from Isu1 and transferred toward apoproteins with the help of a dedicated Hsp70 chaperone system and the glutaredoxin Grx5. Finally, various specialized ISC components assist in the generation of [4Fe-4S] clusters and cluster insertion into specific target apoproteins. Functional defects of the core ISC assembly machinery are signaled to cytosolic or nuclear iron regulatory systems resulting in increased cellular iron acquisition and mitochondrial iron accumulation. In fungi, regulation is achieved by iron-responsive transcription factors controlling the expression of genes involved in iron uptake and intracellular distribution. They are assisted by cytosolic multidomain glutaredoxins which use a bound Fe/S cluster as iron sensor and additionally perform an essential role in intracellular iron delivery to target metalloproteins. In mammalian cells, the iron regulatory proteins IRP1, an Fe/S protein, and IRP2 act in a post-transcriptional fashion to adjust the cellular needs for iron. Thus, Fe/S protein biogenesis and cellular iron metabolism are tightly linked to coordinate iron supply and utilization. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Affiliation(s)
- Roland Lill
- Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch Str. 6, 35033 Marburg, Germany.
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142
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Xu N, Cheng X, Yu Q, Zhang B, Ding X, Xing L, Li M. Identification and functional characterization of mitochondrial carrier Mrs4 in Candida albicans. FEMS Yeast Res 2012; 12:844-58. [PMID: 22846114 DOI: 10.1111/j.1567-1364.2012.00835.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 07/23/2012] [Accepted: 07/24/2012] [Indexed: 11/30/2022] Open
Abstract
Iron is an essential nutrient required for the growth and metabolism in Candida albicans. Here, we for the first time identified Mrs4 as a new member of mitochondrial carrier family in C. albicans. Our experiments revealed that C. albicans Mrs4 (CaMrs4) is localized to the mitochondria and required for mitochondrial morphology. We found that CaMrs4 is required for cell growth, and the mrs4Δ/Δ mutant showed a more severe growth defect in iron deficiency. Deletion of MRS4 affected cellular iron content by altering the expression of iron regulon genes in C. albicans, such as AFT2, SMF3, FTR1 and ISU1. Candida albicans Aft2 factor functions as a negative regulator of MRS4 expression through the CACCC Aft-type sequence in a gene dose-dependent fashion. In addition, the mrs4Δ/Δ mutant exhibited hypersensitivity to oxidants and most metal ions, but decreased sensitivity to cobalt. Exogenous iron could suppress the sensitivity of the mrs4Δ/Δ mutant to oxidants and most metal ions, suggesting that the role of CaMrs4 is partially mediated by iron availability. Furthermore, deletion of MRS4 resulted in delayed filamentation under tested conditions. Taken together, these findings characterize a new mitochondrial carrier and provide a novel insight into the role of CaMrs4 in mitochondrial function.
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Affiliation(s)
- Ning Xu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, Tianjin, China
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143
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Yao H, Wang Y, Lovell S, Kumar R, Ruvinsky AM, Battaile KP, Vakser IA, Rivera M. The structure of the BfrB-Bfd complex reveals protein-protein interactions enabling iron release from bacterioferritin. J Am Chem Soc 2012; 134:13470-81. [PMID: 22812654 PMCID: PMC3428730 DOI: 10.1021/ja305180n] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ferritin-like molecules are unique to cellular iron homeostasis because they can store iron at concentrations much higher than those dictated by the solubility of Fe(3+). Very little is known about the protein interactions that deliver iron for storage or promote the mobilization of stored iron from ferritin-like molecules. Here, we report the X-ray crystal structure of Pseudomonas aeruginosa bacterioferritin (Pa-BfrB) in complex with bacterioferritin-associated ferredoxin (Pa-Bfd) at 2.0 Å resolution. As the first example of a ferritin-like molecule in complex with a cognate partner, the structure provides unprecedented insight into the complementary interface that enables the [2Fe-2S] cluster of Pa-Bfd to promote heme-mediated electron transfer through the BfrB protein dielectric (~18 Å), a process that is necessary to reduce the core ferric mineral and facilitate mobilization of Fe(2+). The Pa-BfrB-Bfd complex also revealed the first structure of a Bfd, thus providing a first view to what appears to be a versatile metal binding domain ubiquitous to the large Fer2_BFD family of proteins and enzymes with diverse functions. Residues at the Pa-BfrB-Bfd interface are highly conserved in Bfr and Bfd sequences from a number of pathogenic bacteria, suggesting that the specific recognition between Pa-BfrB and Pa-Bfd is of widespread significance to the understanding of bacterial iron homeostasis.
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Affiliation(s)
- Huili Yao
- Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr., Lawrence, KS 66047
| | - Yan Wang
- Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr., Lawrence, KS 66047
| | - Scott Lovell
- Del Shankel Structural Biology Center, University of Kansas, 2034 Becker Dr., Lawrence, KS 66047
| | - Ritesh Kumar
- Center for Bioinformatics, University of Kansas, 2030 Becker Dr., Lawrence, KS 66047
| | - Anatoly M. Ruvinsky
- Center for Bioinformatics, University of Kansas, 2030 Becker Dr., Lawrence, KS 66047
| | - Kevin P. Battaile
- IMCA-CAT, Hauptman Woodward Medical Research Institute, 9700 S. Cass Avenue, Bldg. 435A, Argonne, IL 60439
| | - Ilya A. Vakser
- Center for Bioinformatics, University of Kansas, 2030 Becker Dr., Lawrence, KS 66047
| | - Mario Rivera
- Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr., Lawrence, KS 66047
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144
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Sawai H, Yamanaka M, Sugimoto H, Shiro Y, Aono S. Structural basis for the transcriptional regulation of heme homeostasis in Lactococcus lactis. J Biol Chem 2012; 287:30755-68. [PMID: 22798069 DOI: 10.1074/jbc.m112.370916] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although heme is a crucial element for many biological processes including respiration, heme homeostasis should be regulated strictly due to the cytotoxicity of free heme molecules. Numerous lactic acid bacteria, including Lactococcus lactis, acquire heme molecules exogenously to establish an aerobic respiratory chain. A heme efflux system plays an important role for heme homeostasis to avoid cytotoxicity of acquired free heme, but its regulatory mechanism is not clear. Here, we report that the transcriptional regulator heme-regulated transporter regulator (HrtR) senses and binds a heme molecule as its physiological effector to regulate the expression of the heme-efflux system responsible for heme homeostasis in L. lactis. To elucidate the molecular mechanisms of how HrtR senses a heme molecule and regulates gene expression for the heme efflux system, we determined the crystal structures of the apo-HrtR·DNA complex, apo-HrtR, and holo-HrtR at a resolution of 2.0, 3.1, and 1.9 Å, respectively. These structures revealed that HrtR is a member of the TetR family of transcriptional regulators. The residue pair Arg-46 and Tyr-50 plays a crucial role for specific DNA binding through hydrogen bonding and a CH-π interaction with the DNA bases. HrtR adopts a unique mechanism for its functional regulation upon heme sensing. Heme binding to HrtR causes a coil-to-helix transition of the α4 helix in the heme-sensing domain, which triggers a structural change of HrtR, causing it to dissociate from the target DNA for derepression of the genes encoding the heme efflux system. HrtR uses a unique heme-sensing motif with bis-His (His-72 and His-149) ligation to the heme, which is essential for the coil-to-helix transition of the α4 helix upon heme sensing.
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Affiliation(s)
- Hitomi Sawai
- Okazaki Institute for Integrative Bioscience and Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan
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145
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Feng Q, Migas MC, Waheed A, Britton RS, Fleming RE. Ferritin upregulates hepatic expression of bone morphogenetic protein 6 and hepcidin in mice. Am J Physiol Gastrointest Liver Physiol 2012; 302:G1397-404. [PMID: 22517766 PMCID: PMC3378091 DOI: 10.1152/ajpgi.00020.2012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepcidin is a hepatocellular hormone that inhibits the release of iron from certain cell populations, including enterocytes and reticuloendothelial cells. The regulation of hepcidin (HAMP) gene expression by iron status is mediated in part by the signaling molecule bone morphogenetic protein 6 (BMP6). We took advantage of the low iron status of juvenile mice to characterize the regulation of Bmp6 and Hamp1 expression by iron administered in three forms: 1) ferri-transferrin (Fe-Tf), 2) ferric ammonium citrate (FAC), and 3) liver ferritin. Each of these forms of iron enters cells by distinct mechanisms and chemical forms. Iron was parenterally administered to 10-day-old mice, and hepatic expression of Bmp6 and Hamp1 mRNAs was measured 6 h later. We observed that hepatic Bmp6 expression increased in response to ferritin but was unchanged by Fe-Tf or FAC. Hepatic Hamp1 expression likewise increased in response to ferritin and Fe-Tf but was decreased by FAC. Exogenous ferritin increased Bmp6 and Hamp1 expression in older mice as well. Removing iron from ferritin markedly decreased its effect on Bmp6 expression. Exogenously administered ferritin and the derived iron localized in the liver primarily to sinusoidal lining cells. Moreover, expression of Bmp6 mRNA in isolated adult rodent liver cells was much higher in sinusoidal lining cells than hepatocytes (endothelial >> stellate > Kupffer). We conclude that exogenous iron-containing ferritin upregulates hepatic Bmp6 expression, and we speculate that liver ferritin contributes to regulation of Bmp6 and, thus, Hamp1 genes.
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Affiliation(s)
- Qi Feng
- 1Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri;
| | - Mary C. Migas
- 1Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri;
| | - Abdul Waheed
- 3Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Robert S. Britton
- 2Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, Missouri; and
| | - Robert E. Fleming
- 1Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, Missouri; ,3Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri
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146
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Li Y, Lin L, Li Z, Ye X, Xiong K, Aryal B, Xu Z, Paroo Z, Liu Q, He C, Jin P. Iron homeostasis regulates the activity of the microRNA pathway through poly(C)-binding protein 2. Cell Metab 2012; 15:895-904. [PMID: 22633452 PMCID: PMC3613991 DOI: 10.1016/j.cmet.2012.04.021] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 03/05/2012] [Accepted: 04/27/2012] [Indexed: 12/20/2022]
Abstract
MicroRNAs (miRNAs) control gene expression by promoting degradation or repressing translation of target mRNAs. The components of the miRNA pathway are subject to diverse modifications that can modulate the abundance and function of miRNAs. Iron is essential for fundamental metabolic processes, and its homeostasis is tightly regulated. Here we identified iron chelators as a class of activator of the miRNA pathway that could promote the processing of miRNA precursors. We show that cytosolic iron could regulate the activity of the miRNA pathway through poly(C)-binding protein 2 (PCBP2). PCBP2 is associated with Dicer and promotes the processing of miRNA precursors. Cytosolic iron could modulate the association between PCBP2 and Dicer, as well as the multimerization of PCBP2 and its ability to bind to miRNA precursors, which can alter the processing of miRNA precursors. Our findings reveal a role of iron homeostasis in the regulation of miRNA biogenesis.
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Affiliation(s)
- Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA
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147
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Athavale SS, Petrov AS, Hsiao C, Watkins D, Prickett CD, Gossett JJ, Lie L, Bowman JC, O'Neill E, Bernier CR, Hud NV, Wartell RM, Harvey SC, Williams LD. RNA folding and catalysis mediated by iron (II). PLoS One 2012; 7:e38024. [PMID: 22701543 PMCID: PMC3365117 DOI: 10.1371/journal.pone.0038024] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 04/28/2012] [Indexed: 01/06/2023] Open
Abstract
Mg2+ shares a distinctive relationship with RNA, playing important and specific roles in the folding and function of essentially all large RNAs. Here we use theory and experiment to evaluate Fe2+ in the absence of free oxygen as a replacement for Mg2+ in RNA folding and catalysis. We describe both quantum mechanical calculations and experiments that suggest that the roles of Mg2+ in RNA folding and function can indeed be served by Fe2+. The results of quantum mechanical calculations show that the geometry of coordination of Fe2+ by RNA phosphates is similar to that of Mg2+. Chemical footprinting experiments suggest that the conformation of the Tetrahymena thermophila Group I intron P4–P6 domain RNA is conserved between complexes with Fe2+ or Mg2+. The catalytic activities of both the L1 ribozyme ligase, obtained previously by in vitro selection in the presence of Mg2+, and the hammerhead ribozyme are enhanced in the presence of Fe2+ compared to Mg2+. All chemical footprinting and ribozyme assays in the presence of Fe2+ were performed under anaerobic conditions. The primary motivation of this work is to understand RNA in plausible early earth conditions. Life originated during the early Archean Eon, characterized by a non-oxidative atmosphere and abundant soluble Fe2+. The combined biochemical and paleogeological data are consistent with a role for Fe2+ in an RNA World. RNA and Fe2+ could, in principle, support an array of RNA structures and catalytic functions more diverse than RNA with Mg2+ alone.
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Affiliation(s)
- Shreyas S. Athavale
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Anton S. Petrov
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Chiaolong Hsiao
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Derrick Watkins
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Caitlin D. Prickett
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - J. Jared Gossett
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Lively Lie
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Jessica C. Bowman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Eric O'Neill
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Chad R. Bernier
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Nicholas V. Hud
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Roger M. Wartell
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Stephen C. Harvey
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Loren Dean Williams
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- NAI Center for Ribosomal Origins and Evolution, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- * E-mail:
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148
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Fe2+ binds iron responsive element-RNA, selectively changing protein-binding affinities and regulating mRNA repression and activation. Proc Natl Acad Sci U S A 2012; 109:8417-22. [PMID: 22586079 DOI: 10.1073/pnas.1120045109] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Iron increases synthesis rates of proteins encoded in iron-responsive element (IRE)-mRNAs; metabolic iron ("free," "labile") is Fe(2+). The noncoding IRE-RNA structure, approximately 30 nt, folds into a stem loop to control synthesis of proteins in iron trafficking, cell cycling, and nervous system function. IRE-RNA riboregulators bind specifically to iron-regulatory proteins (IRP) proteins, inhibiting ribosome binding. Deletion of the IRE-RNA from an mRNA decreases both IRP binding and IRP-independent protein synthesis, indicating effects of other "factors." Current models of IRE-mRNA regulation, emphasizing iron-dependent degradation/modification of IRP, lack answers about how iron increases IRE-RNA/IRP protein dissociation or how IRE-RNA, after IRP dissociation, influences protein synthesis rates. However, we observed Fe(2+) (anaerobic) or Mn(2+) selectively increase the IRE-RNA/IRP K(D). Here we show: (i) Fe(2+) binds to the IRE-RNA, altering its conformation (by 2-aminopurine fluorescence and ethidium bromide displacement); (ii) metal ions increase translation of IRE-mRNA in vitro; (iii) eukaryotic initiation factor (eIF)4F binds specifically with high affinity to IRE-RNA; (iv) Fe(2+) increased eIF4F/IRE-RNA binding, which outcompetes IRP binding; (v) exogenous eIF4F rescued metal-dependent IRE-RNA translation in eIF4F-depeleted extracts. The regulation by metabolic iron binding to IRE-RNA to decrease inhibitor protein (IRP) binding and increase activator protein (eIF4F) binding identifies IRE-RNA as a riboregulator.
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149
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Wu H, Bai Y, Yuan J, Wang H, Pan G, Fan X, Kong J. Synthesis, Crystal Structures and DNA-Binding Properties of a Six-Coordinate Ternary Iron (III) Complex Formed with Tris(2-[N-Ethyl]Benzimidazylmethyl)Amine and Salicylate. JOURNAL OF CHEMICAL RESEARCH 2012. [DOI: 10.3184/174751912x13333744940255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A ternary Fe(III) complex with a tripodal ligand tris(2-[ N-ethyl]benzimidazlylmethyl)amine (Etntb) and salicylate, with composition [Fe(Etntb)(salicylate)](NO3)·MeOH, has been synthesised. Its crystal structure shows that the central Fe(III) atom is six-coordinated and forms a distorted octahedral structure. The DNA-binding properties of the Fe(III) complex have been investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Fe(III) complex binds to DNA via an intercalation binding mode. Additionally, the Fe(III) complex scavenges hydroxyl radicals in in vitro studies.
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Affiliation(s)
- Huilu Wu
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Ying Bai
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Jingkun Yuan
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Hua Wang
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Guolong Pan
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Xuyang Fan
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
| | - Jin Kong
- School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, P. R. China
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Correnti C, Strong RK. Mammalian siderophores, siderophore-binding lipocalins, and the labile iron pool. J Biol Chem 2012; 287:13524-31. [PMID: 22389496 PMCID: PMC3340207 DOI: 10.1074/jbc.r111.311829] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Bacteria use tight-binding, ferric-specific chelators called siderophores to acquire iron from the environment and from the host during infection; animals use proteins such as transferrin and ferritin to transport and store iron. Recently, candidate compounds that could serve endogenously as mammalian siderophore equivalents have been identified and characterized through associations with siderocalin, the only mammalian siderophore-binding protein currently known. Siderocalin, an antibacterial protein, acts by sequestering iron away from infecting bacteria as siderophore complexes. Candidate endogenous siderophores include compounds that only effectively transport iron as ternary complexes with siderocalin, explaining pleiotropic activities in normal cellular processes and specific disease states.
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Affiliation(s)
- Colin Correnti
- From the Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
| | - Roland K. Strong
- From the Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
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