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Dang J, Wang N, Atiyeh HK. Review of Dissolved CO and H 2 Measurement Methods for Syngas Fermentation. SENSORS (BASEL, SWITZERLAND) 2021; 21:2165. [PMID: 33808889 PMCID: PMC8003665 DOI: 10.3390/s21062165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/03/2021] [Accepted: 03/12/2021] [Indexed: 11/16/2022]
Abstract
Syngas fermentation is a promising technique to produce biofuels using syngas obtained through gasified biomass and other carbonaceous materials or collected from industrial CO-rich off-gases. The primary components of syngas, carbon monoxide (CO) and hydrogen (H2), are converted to alcohols and other chemicals through an anaerobic fermentation process by acetogenic bacteria. Dissolved CO and H2 concentrations in fermentation media are among the most important parameters for successful and stable operation. However, the difficulties in timely and precise dissolved CO and H2 measurements hinder the industrial-scale commercialization of this technique. The purpose of this article is to provide a comprehensive review of available dissolved CO and H2 measurement methods, focusing on their detection mechanisms, CO and H2 cross interference and operations in syngas fermentation process. This paper further discusses potential novel methods by providing a critical review of gas phase CO and H2 detection methods with regard to their capability to be modified for measuring dissolved CO and H2 in syngas fermentation conditions.
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Affiliation(s)
| | - Ning Wang
- Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA; (J.D.); (H.K.A.)
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2
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Shandilya M, Kumar G, Gomkale R, Singh S, Khan MA, Kateriya S, Kundu S. Multiple putative methemoglobin reductases in C. reinhardtii may support enzymatic functions for its multiple hemoglobins. Int J Biol Macromol 2021; 171:465-479. [PMID: 33428952 DOI: 10.1016/j.ijbiomac.2021.01.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/26/2020] [Accepted: 01/05/2021] [Indexed: 10/22/2022]
Abstract
The ubiquitous nature of hemoglobins, their presence in multiple forms and low cellular expression in organisms suggests alternative physiological functions of hemoglobins in addition to oxygen transport and storage. Previous research has proposed enzymatic function of hemoglobins such as nitric oxide dioxygenase, nitrite reductase and hydroxylamine reductase. In all these enzymatic functions, active ferrous form of hemoglobin is converted to ferric form and reconversion of ferric to ferrous through reduction partners is under active investigation. The model alga C. reinhardtii contains multiple globins and is thus expected to have multiple putative methemoglobin reductases to augment the physiological functions of the novel hemoglobins. In this regard, three putative methemoglobin reductases and three algal hemoglobins were characterized. Our results signify that the identified putative methemoglobin reductases can reduce algal methemoglobins in a nonspecific manner under in vitro conditions. Enzyme kinetics of two putative methemoglobin reductases with methemoglobins as substrates and in silico analysis support interaction between the hemoglobins and the two reduction partners as also observed in vitro. Our investigation on algal methemoglobin reductases underpins the valuable chemistry of nitric oxide with the newly discovered hemoglobins to ensure their physiological relevance, with multiple hemoglobins probably necessitating the presence of multiple reductases.
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Affiliation(s)
- Manish Shandilya
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India; Amity School of Applied Sciences, Amity University Haryana, Gurugram 122413, India
| | - Gaurav Kumar
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India
| | - Ridhima Gomkale
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India
| | - Swati Singh
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India
| | - Mohd Asim Khan
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India
| | - Suneel Kateriya
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India.
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3
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Ovung A, Mavani A, Chatterjee S, Das A, Suresh Kumar G, Bhuiya S, Das S, Bhattacharyya J. On the Biophysical Investigation of Sulfamethazine‐Hemoglobin Binding and the Resulting Adverse Effects of Antibiotics. ChemistrySelect 2020. [DOI: 10.1002/slct.202003256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Aben Ovung
- Department of Chemistry National Institute of Technology Nagaland, Chumukedima, Dimapur Nagalnd 797103 India
| | - A. Mavani
- Department of Chemistry National Institute of Technology Nagaland, Chumukedima, Dimapur Nagalnd 797103 India
| | - Sabyasachi Chatterjee
- Biophysical Chemistry Laboratory CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road Kolkata 700032 India
| | - Abhi Das
- Biophysical Chemistry Laboratory CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road Kolkata 700032 India
| | - Gopinatha Suresh Kumar
- Biophysical Chemistry Laboratory CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road Kolkata 700032 India
| | - Sutanwi Bhuiya
- Department of Chemistry Jadavpur University, Jadavpur Kolkata 700032 India
| | - Suman Das
- Department of Chemistry Jadavpur University, Jadavpur Kolkata 700032 India
| | - Jhimli Bhattacharyya
- Department of Chemistry National Institute of Technology Nagaland, Chumukedima, Dimapur Nagalnd 797103 India
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4
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Mann M, Miebach K, Büchs J. Online measurement of dissolved carbon monoxide concentrations reveals critical operating conditions in gas fermentation experiments. Biotechnol Bioeng 2020; 118:253-264. [PMID: 32940909 DOI: 10.1002/bit.27567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 09/11/2020] [Indexed: 11/07/2022]
Abstract
Syngas fermentation is one possible contributor to the reduction of greenhouse gas emissions. The conversion of industrial waste gas streams containing CO or H2 , which are usually combusted, directly reduces the emission of CO2 into the atmosphere. Additionally, other carbon-containing waste streams can be gasified, making them accessible for microbial conversion into platform chemicals. However, there is still a lack of detailed process understanding, as online monitoring of dissolved gas concentrations is currently not possible. Several studies have demonstrated growth inhibition of Clostridium ljungdahlii at high CO concentrations in the headspace. However, growth is not inhibited by the CO concentration in the headspace, but by the dissolved carbon monoxide tension (DCOT). The DCOT depends on the CO concentration in the headspace, CO transfer rate, and biomass concentration. Hence, the measurement of the DCOT is a superior method to investigate the toxic effects of CO on microbial fermentation. Since CO is a component of syngas, a detailed understanding is crucial. In this study, a newly developed measurement setup is presented that allows sterile online measurement of the DCOT. In an abiotic experiment, the functionality of the measurement principle was demonstrated for various CO concentrations in the gas supply (0%-40%) and various agitation rates (300-1100 min-1 ). In continuous stirred tank reactor fermentation experiments, the measurement showed reliable results. The production of ethanol and 2,3-butanediol increased with increasing DCOT. Moreover, a critical DCOT was identified, leading to the inhibition of the culture. Thus, the reported online measurement method is beneficial for process understanding. In future processes, it can be used for closed-loop fermentation control.
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Affiliation(s)
- Marcel Mann
- AVT, Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Katharina Miebach
- AVT, Biochemical Engineering, RWTH Aachen University, Aachen, Germany
| | - Jochen Büchs
- AVT, Biochemical Engineering, RWTH Aachen University, Aachen, Germany
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5
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Van Hecke W, Bockrath R, De Wever H. Effects of moderately elevated pressure on gas fermentation processes. BIORESOURCE TECHNOLOGY 2019; 293:122129. [PMID: 31558339 DOI: 10.1016/j.biortech.2019.122129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
Industrial biotechnology has a potential to tackle harmful CO2 emissions and turn CO2 into a valuable commodity. However, a major technical obstacle in gas fermentations is the limited gas mass transfer rate. Increasing system pressure is a way to increase the driving force for mass transfer. This review presents critical aspects of gas fermentation at elevated pressure, with a specific focus on results obtained at 5-10 bar. While a solid foundation for high pressure fermentations has already been laid in the past, mainly to enhance oxygen transfer rates, it can be concluded that fermentations at moderately elevated pressures using gases such as CO2, CH4, CO, H2, O2 are still underexplored. Microbial growth rates and product formation can be improved at higher pressures, but in general, titers and productivities need to be increased to allow a further industrialization. Hence, more systematic investigations and techno-economic assessments are required.
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Affiliation(s)
- Wouter Van Hecke
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, Belgium
| | | | - Heleen De Wever
- Separation and Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, Belgium.
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6
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Wierzchowski M, Łażewski D, Tardowski T, Grochocka M, Czajkowski R, Sobiak S, Sobotta L. Nanomolar photodynamic activity of porphyrins bearing 1,4,7-trioxanonyl and 2-methyl-5-nitroimidazole moieties against cancer cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 202:111703. [PMID: 31810036 DOI: 10.1016/j.jphotobiol.2019.111703] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/21/2019] [Accepted: 11/11/2019] [Indexed: 02/02/2023]
Abstract
Despite the continuous development of medicine, there is still a lack of effective and fully safe protocols for the treatment of neoplastic diseases. The drug-drug conjugates approach seems to give a chance to obtain more efficient molecules. New alkoxy and metronidazole substituted porphyrins were synthesized. Novel porphyrins were purified by flash column chromatography and characterized using NMR, MS, UV-Vis and HPLC. The Nuclear Magnetic Resonance study was performed to annotate experimentally observed 1H NMR and 13C NMR signals of new compounds. The 2D NMR techniques such as 1H-1H COSY (Correlation Spectroscopy), 1H-13C HSQC (Heteronuclear Single Quantum Correlation) and 1H-13C HMBC (Heteronuclear Multiple Bond Correlation) were used for the structure elucidation of the new compounds. In the range of 250-450 nm of the absorption spectra, the Soret band was observed, whereas the Q band was noted in the range of 500-650 nm. Compounds revealed a fluorescence quantum yield in the range 0.03-0.12. Singlet oxygen generation quantum yields up to 0.54 were determined. Electrochemical properties has also been studied. It has been noticed electropolymerization of compound bearing 5-nitroimidazole substituents. The photodynamic activity of the studied porphyrins against A549 and HEK001/HPV16 cancer cells were examined. The most active against A549 and HEK 001/HPV16 was light-excited trioxanonylporphyrin with the values of IC50 equal to 0.49 μM and 50 nM respectively.
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Affiliation(s)
- Marcin Wierzchowski
- Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.
| | - Dawid Łażewski
- Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland
| | - Tadeusz Tardowski
- Sexually Transmitted Diseases and Immunodermatology, Collegium Medicum of Nicolaus Copernicus University in Toruń, Curie Skłodowska 9, 85-094 Bydgoszcz, Poland
| | - Małgorzata Grochocka
- Sexually Transmitted Diseases and Immunodermatology, Collegium Medicum of Nicolaus Copernicus University in Toruń, Curie Skłodowska 9, 85-094 Bydgoszcz, Poland
| | - Rafal Czajkowski
- Sexually Transmitted Diseases and Immunodermatology, Collegium Medicum of Nicolaus Copernicus University in Toruń, Curie Skłodowska 9, 85-094 Bydgoszcz, Poland
| | - Stanislaw Sobiak
- Department of Inorganic and Analytical Chemistry, Collegium Medicum of Nicolaus Copernicus University in Toruń, A. Jurasza 2, 85-089 Bydgoszcz, Poland
| | - Lukasz Sobotta
- Department of Inorganic and Analytical Chemistry, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland
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7
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Volumetric mass transfer coefficient for carbon monoxide in a dual impeller stirred tank reactor considering a perfluorocarbon–water mixture as liquid phase. Chem Eng Res Des 2019. [DOI: 10.1016/j.cherd.2019.01.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Riegler P, Chrusciel T, Mayer A, Doll K, Weuster-Botz D. Reversible retrofitting of a stirred-tank bioreactor for gas-lift operation to perform synthesis gas fermentation studies. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2018.09.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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9
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Jang N, Yasin M, Park S, Lovitt RW, Chang IS. Determination of volumetric gas-liquid mass transfer coefficient of carbon monoxide in a batch cultivation system using kinetic simulations. BIORESOURCE TECHNOLOGY 2017; 239:387-393. [PMID: 28531864 DOI: 10.1016/j.biortech.2017.05.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/30/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas-liquid mass transfer coefficient (kLa) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (Cace), headspace gas (Nco and [Formula: see text] ), dissolved CO concentration in the fermentation medium (Cco), and mass transfer rate (R) were simulated using a variety of kLa values. The simulated results showed excellent agreement with the experimental data for a kLa of 13/hr. The Cco values decreased with increase in cultivation times, whereas the maximum mass transfer rate was achieved at the mid-log phase due to vigorous microbial CO consumption rate higher than R. The model suggested in this study may be applied to a variety of microbial systems involving gaseous substrates.
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Affiliation(s)
- Nulee Jang
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Muhammad Yasin
- Department of Chemical Engineering, COMSATS Institute of Information Technology (CIIT), Lahore, Pakistan
| | - Shinyoung Park
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Robert W Lovitt
- College of Engineering, Center of Complex Fluids Processing, Multidisciplinary Nanotechnology Centre, Swansea University, Swansea SA2 8PP, UK
| | - In Seop Chang
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea.
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10
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Residues in the Distal Heme Pocket of Arabidopsis Non-Symbiotic Hemoglobins: Implication for Nitrite Reductase Activity. Int J Mol Sci 2016; 17:ijms17050640. [PMID: 27136534 PMCID: PMC4881466 DOI: 10.3390/ijms17050640] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/13/2016] [Accepted: 04/19/2016] [Indexed: 02/08/2023] Open
Abstract
It is well-established that plant hemoglobins (Hbs) are involved in nitric oxide (NO) metabolism via NO dioxygenase and/or nitrite reductase activity. The ferrous-deoxy Arabidopsis Hb1 and Hb2 (AHb1 and AHb2) have been shown to reduce nitrite to NO under hypoxia. Here, to test the hypothesis that a six- to five-coordinate heme iron transition might mediate the control of the nitrite reduction rate, we examined distal pocket mutants of AHb1 and AHb2 for nitrite reductase activity, NO production and spectroscopic features. Absorption spectra of AHbs distal histidine mutants showed that AHb1 mutant (H69L) is a stable pentacoordinate high-spin species in both ferrous and ferric states, whereas heme iron in AHb2 mutant (H66L) is hexacoordinated low-spin with Lys69 as the sixth ligand. The bimolecular rate constants for nitrite reduction to NO were 13.3 ± 0.40, 7.3 ± 0.5, 10.6 ± 0.8 and 171.90 ± 9.00 M−1·s−1 for AHb1, AHb2, AHb1 H69L and AHb2 H66L, respectively, at pH 7.4 and 25 °C. Consistent with the reductase activity, the amount of NO detected by chemiluminescence was significantly higher in the AHb2 H66L mutant. Our data indicate that nitrite reductase activity is determined not only by heme coordination, but also by a unique distal heme pocket in each AHb.
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11
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Adaptive engineering of a hyperthermophilic archaeon on CO and discovering the underlying mechanism by multi-omics analysis. Sci Rep 2016; 6:22896. [PMID: 26975345 PMCID: PMC4791640 DOI: 10.1038/srep22896] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 02/23/2016] [Indexed: 01/03/2023] Open
Abstract
The hyperthermophilic archaeon Thermococcus onnurineus NA1 can grow and produce H2 on carbon monoxide (CO) and its H2 production rates have been improved through metabolic engineering. In this study, we applied adaptive evolution to enhance H2 productivity. After over 150 serial transfers onto CO medium, cell density, CO consumption rate and H2 production rate increased. The underlying mechanism for those physiological changes could be explained by using multi-omics approaches including genomic, transcriptomic and epigenomic analyses. A putative transcriptional regulator was newly identified to regulate the expression levels of genes related to CO oxidation. Transcriptome analysis revealed significant changes in the transcript levels of genes belonging to the categories of transcription, translation and energy metabolism. Our study presents the first genome-scale methylation pattern of hyperthermophilic archaea. Adaptive evolution led to highly enhanced H2 productivity at high CO flow rates using synthesis gas produced from coal gasification.
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Mira MM, Adel ES, Stasolla C. Ethylene is integrated into the nitric oxide regulation of Arabidopsis somatic embryogenesis. J Genet Eng Biotechnol 2015; 13:7-17. [PMID: 30647561 PMCID: PMC6299816 DOI: 10.1016/j.jgeb.2015.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/18/2014] [Accepted: 01/10/2015] [Indexed: 01/07/2023]
Abstract
The study confirms the role of the two Arabidopsis hemoglobin genes (Glb1 and Glb2) during somatic embryogenesis and proposes the involvement of ethylene in the regulation of embryo development. Suppression of both Glb1 and Glb2 results in accumulation of nitric oxide (NO) and a different embryogenic response. Compared to WT tissue, down-regulation of Glb1 (Glb1 RNAi line) compromises the embryogenic process, while repression of Glb2 (Glb2-/- line) increases the number of embryos. These differences were ascribed to the differential accumulation of NO in the two lines, as Glb1 is a more effective NO scavenger compared to Glb2. A high elevation of NO level [achieved pharmacologically using the NO donor sodium nitroprusside (SNP), or genetically using the Glb1 suppressing line], activated the two ethylene biosynthetic genes 1-aminocyclopropane-1-carboxylate synthase (ACC synthase) and 1-aminocyclopropane-1-carboxylate oxidase (ACC oxidase). Ethylene accumulation repressed embryogenesis, as shown by the decreased embryo number observed in tissue treated with the ethylene releasing agent Ethephon (ETH), as well as by the increased embryo production obtained with the two ethylene insensitive mutant lines (ein2-1 and ein3-1). A repression in ethylene level increased the expression of many auxin biosynthetic genes and favored the accumulation of the auxin indole-acetic acid (IAA) at the sites of the explants where embryogenic tissue will form. Collectively these data reveal that high levels of NO, generated by the Glb1 suppressing line, but not by the Glb2 suppressing line, might increase the level of ethylene, which represses the production of auxin. Auxin is the inductive signal required for the formation of the embryogenic tissue.
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Affiliation(s)
- Mohamed M. Mira
- Department of Botany, Faculty of Science, Tanta University, Tanta 31527, Egypt
| | - El-Shanshory Adel
- Department of Botany, Faculty of Science, Tanta University, Tanta 31527, Egypt
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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13
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Affiliation(s)
- Luisa B. Maia
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - José J. G. Moura
- REQUIMTE/CQFB, Departamento
de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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14
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Syngas fermentation of Clostridium carboxidivoran P7 in a hollow fiber membrane biofilm reactor: Evaluating the mass transfer coefficient and ethanol production performance. Biochem Eng J 2014. [DOI: 10.1016/j.bej.2014.01.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Munasinghe PC, Khanal SK. Evaluation of hydrogen and carbon monoxide mass transfer and a correlation between the myoglobin-protein bioassay and gas chromatography method for carbon monoxide determination. RSC Adv 2014. [DOI: 10.1039/c4ra04696j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Myoglobin-protein bioassay, which is a much simpler, faster and cheaper method compared well with GC analysis, can be used as a reliable method of determining the volumetric mass transfer coefficient of CO in syngas fermentation studies.
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Affiliation(s)
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering (MBBE)
- University of Hawai'i at Mānoa
- Honolulu, USA
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16
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Wang X, Hargrove MS. Nitric oxide in plants: the roles of ascorbate and hemoglobin. PLoS One 2013; 8:e82611. [PMID: 24376554 PMCID: PMC3869716 DOI: 10.1371/journal.pone.0082611] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/04/2013] [Indexed: 11/18/2022] Open
Abstract
Ascorbic acid and hemoglobins have been linked to nitric oxide metabolism in plants. It has been hypothesized that ascorbic acid directly reduces plant hemoglobin in support of NO scavenging, producing nitrate and monodehydroascorbate. In this scenario, monodehydroascorbate reductase uses NADH to reduce monodehydroascorbate back to ascorbate to sustain the cycle. To test this hypothesis, rates of rice nonsymbiotic hemoglobin reduction by ascorbate were measured directly, in the presence and absence of purified rice monodehydroascorbate reductase and NADH. Solution NO scavenging was also measured methodically in the presence and absence of rice nonsymbiotic hemoglobin and monodehydroascorbate reductase, under hypoxic and normoxic conditions, in an effort to gauge the likelihood of these proteins affecting NO metabolism in plant tissues. Our results indicate that ascorbic acid slowly reduces rice nonsymbiotic hemoglobin at a rate identical to myoglobin reduction. The product of the reaction is monodehydroascorbate, which can be efficiently reduced back to ascorbate in the presence of monodehydroascorbate reductase and NADH. However, our NO scavenging results suggest that the direct reduction of plant hemoglobin by ascorbic acid is unlikely to serve as a significant factor in NO metabolism, even in the presence of monodehydroascorbate reductase. Finally, the possibility that the direct reaction of nitrite/nitrous acid and ascorbic acid produces NO was measured at various pH values mimicking hypoxic plant cells. Our results suggest that this reaction is a likely source of NO as the plant cell pH drops below 7, and as nitrite concentrations rise to mM levels during hypoxia.
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Affiliation(s)
- Xiaoguang Wang
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Mark S. Hargrove
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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17
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Royo B, Sosna M, Asensio AC, Moran JF, Ferapontova EE. Direct electrochemistry and environmental sensing of rice hemoglobin immobilized at graphite electrodes. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2013.06.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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18
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Morzan UN, Capece L, Marti MA, Estrin DA. Quaternary structure effects on the hexacoordination equilibrium in rice hemoglobin rHb1: Insights from molecular dynamics simulations. Proteins 2013; 81:863-73. [DOI: 10.1002/prot.24245] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 12/11/2012] [Accepted: 12/14/2012] [Indexed: 11/09/2022]
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19
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Abstract
Approximately, 20 years ago, a haemoglobin gene was identified within the genome of the cyanobacterium Nostoc commune. Haemoglobins have now been confirmed in multiple species of photosynthetic microbes beyond N. commune, and the diversity of these proteins has recently come under increased scrutiny. This chapter summarizes the state of knowledge concerning the phylogeny, physiology and chemistry of globins in cyanobacteria and green algae. Sequence information is by far the best developed and the most rapidly expanding aspect of the field. Structural and ligand-binding properties have been described for just a few proteins. Physiological data are available for even fewer. Although activities such as nitric oxide dioxygenation and oxygen scavenging are strong candidates for cellular function, dedicated studies will be required to complete the story on this intriguing and ancient group of proteins.
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20
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Munasinghe PC, Khanal SK. Syngas fermentation to biofuel: evaluation of carbon monoxide mass transfer and analytical modeling using a composite hollow fiber (CHF) membrane bioreactor. BIORESOURCE TECHNOLOGY 2012; 122:130-136. [PMID: 22494572 DOI: 10.1016/j.biortech.2012.03.053] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/15/2012] [Accepted: 03/16/2012] [Indexed: 05/31/2023]
Abstract
In this study, the volumetric mass transfer coefficients (Ka) for CO were examined in a composite hollow fiber (CHF) membrane bioreactor. The mass transfer experiments were conducted at various inlet gas pressures (from 5 to 30 psig (34.5-206.8 kPa(g))) and recirculation flow rates (300, 600, 900, 1200 and 1500 mL/min) through CHF module. The highest Ka value of 946.6 1/h was observed at a recirculation rate of 1500 mL/min and at an inlet gas pressure of 30 psig(206.8 kPa(g)). The findings of this study confirm that the use of CHF membranes is effective and improves the efficiency CO mass transfer into the aqueous phase.
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Affiliation(s)
- Pradeep Chaminda Munasinghe
- Department of Molecular Biosciences and Bioengineering (MBBE), University of Hawai'i at Mānoa, Agricultural Science Building 218, 1955 East-West Road, Honolulu, HI 96822, USA
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Tiedemann MT, Stillman MJ. Heme binding to the IsdE(M78A; H229A) double mutant: challenging unidirectional heme transfer in the iron-regulated surface determinant protein heme transfer pathway of Staphylococcus aureus. J Biol Inorg Chem 2012; 17:995-1007. [DOI: 10.1007/s00775-012-0914-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 06/07/2012] [Indexed: 10/28/2022]
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22
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Tiso M, Tejero J, Kenney C, Frizzell S, Gladwin MT. Nitrite reductase activity of nonsymbiotic hemoglobins from Arabidopsis thaliana. Biochemistry 2012; 51:5285-92. [PMID: 22620259 DOI: 10.1021/bi300570v] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Plant nonsymbiotic hemoglobins possess hexacoordinate heme geometry similar to that of the heme protein neuroglobin. We recently discovered that deoxygenated neuroglobin converts nitrite to nitric oxide (NO), an important signaling molecule involved in many processes in plants. We sought to determine whether Arabidopsis thaliana nonsymbiotic hemoglobins classes 1 and 2 (AHb1 and AHb2, respectively) might function as nitrite reductases. We found that the reaction of nitrite with deoxygenated AHb1 and AHb2 generates NO gas and iron-nitrosyl-hemoglobin species. The bimolecular rate constants for reduction of nitrite to NO are 19.8 ± 3.2 and 4.9 ± 0.2 M(-1) s(-1), respectively, at pH 7.4 and 25 °C. We determined the pH dependence of these bimolecular rate constants and found a linear correlation with the concentration of protons, indicating the requirement for one proton in the reaction. The release of free NO gas during the reaction under anoxic and hypoxic (2% oxygen) conditions was confirmed by chemiluminescence detection. These results demonstrate that deoxygenated AHb1 and AHb2 reduce nitrite to form NO via a mechanism analogous to that observed for hemoglobin, myoglobin, and neuroglobin. Our findings suggest that during severe hypoxia and in the anaerobic plant roots, especially in species submerged in water, nonsymbiotic hemoglobins provide a viable pathway for NO generation via nitrite reduction.
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Affiliation(s)
- Mauro Tiso
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Bandow N, Gilles VS, Freesmeier B, Semrau JD, Krentz B, Gallagher W, McEllistrem MT, Hartsel SC, Choi DW, Hargrove MS, Heard TM, Chesner LN, Braunreiter KM, Cao BV, Gavitt MM, Hoopes JZ, Johnson JM, Polster EM, Schoenick BD, Umlauf AM, DiSpirito AA. Spectral and copper binding properties of methanobactin from the facultative methanotroph Methylocystis strain SB2. J Inorg Biochem 2012; 110:72-82. [DOI: 10.1016/j.jinorgbio.2012.02.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 01/06/2012] [Accepted: 02/01/2012] [Indexed: 11/25/2022]
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Parent C, Crèvecoeur M, Capelli N, Dat JF. Contrasting growth and adaptive responses of two oak species to flooding stress: role of non-symbiotic haemoglobin. PLANT, CELL & ENVIRONMENT 2011; 34:1113-1126. [PMID: 21410709 DOI: 10.1111/j.1365-3040.2011.02309.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Soil flooding is an environmental constraint that is increasingly important for forest ecosystems, affecting tree growth and regeneration. As a result, selection pressure will alter forest diversity and distribution by favouring tree species tolerant of soil oxygen deprivation. Sessile and pedunculate oaks are the most abundant oak species and they exhibit a strong differential tolerance to waterlogging. In order to gain some understanding of the mechanisms of tolerance of both species to hypoxia, we undertook the characterization of the physiological, morphological, cellular and molecular responses of both species to flooding stress. Our results indicate that pedunculate oak, the more tolerant species, succeeded in maintaining its growth, water status and photosynthetic activity at a higher level than sessile oak. Furthermore, pedunculate oak developed aerenchyma in its root cortex as well as adventitious roots. The later exhibited a strong accumulation of class1 non-symbiotic haemoglobin localized by in situ hybridization in the protoderm and in some cortical cells. In conclusion, the higher tolerance of pedunculate oak to flooding was associated with an enhanced capacity to maintain photosynthesis and water homeostasis, coupled with the development of adaptive features (aerenchyma, adventitious roots) and with a higher expression of non-symbiotic haemoglobin in the roots.
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Affiliation(s)
- Claire Parent
- Laboratoire de Chrono-Environnement,,Université de Franche-Comté, Besançon Cedex, France
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25
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Munasinghe PC, Khanal SK. Syngas fermentation to biofuel: evaluation of carbon monoxide mass transfer coefficient (kLa) in different reactor configurations. Biotechnol Prog 2011; 26:1616-21. [PMID: 20677226 DOI: 10.1002/btpr.473] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lignocellulosic biomass such as agri-residues, agri-processing by-products, and energy crops do not compete with food and feed, and is considered to be the ideal renewable feedstocks for biofuel production. Gasification of biomass produces synthesis gas (syngas), a mixture primarily consisting of CO and H(2). The produced syngas can be converted to ethanol by anaerobic microbial catalysts especially acetogenic bacteria such as various clostridia species.One of the major drawbacks associated with syngas fermentation is the mass transfer limitation of these sparingly soluble gases in the aqueous phase. One way of addressing this issue is the improvement in reactor design to achieve a higher volumetric mass transfer coefficient (k(L)a). In this study, different reactor configurations such as a column diffuser, a 20-μm bulb diffuser, gas sparger, gas sparger with mechanical mixing, air-lift reactor combined with a 20-μm bulb diffuser, air-lift reactor combined with a single gas entry point, and a submerged composite hollow fiber membrane (CHFM) module were employed to examine the k(L) a values. The k(L) a values reported in this study ranged from 0.4 to 91.08 h(-1). The highest k(L) a of 91.08 h(-1) was obtained in the air-lift reactor combined with a 20-μm bulb diffuser, whereas the reactor with the CHFM showed the lowest k(L) a of 0.4 h(-1). By considering both the k(L) a value and the statistical significance of each configuration, the air-lift reactor combined with a 20-μm bulb diffuser was found to be the ideal reactor configuration for carbon monoxide mass transfer in an aqueous phase.
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Affiliation(s)
- Pradeep Chaminda Munasinghe
- Dept. of Molecular Biosciences and Bioengineering, University of Hawai'i at Mānoa, Agricultural Science Building 218, Honolulu, HI 96822, USA
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26
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Kosmachevskaya OV, Topunov AF. Formation of glycated recombinant leghemoglobin in Escherichia coli cells. APPL BIOCHEM MICRO+ 2010. [DOI: 10.1134/s0003683810030087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Smagghe BJ, Hoy JA, Percifield R, Kundu S, Hargrove MS, Sarath G, Hilbert JL, Watts RA, Dennis ES, Peacock WJ, Dewilde S, Moens L, Blouin GC, Olson JS, Appleby CA. Review: correlations between oxygen affinity and sequence classifications of plant hemoglobins. Biopolymers 2010; 91:1083-96. [PMID: 19441024 DOI: 10.1002/bip.21256] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Plants express three phylogenetic classes of hemoglobins (Hb) based on sequence analyses. Class 1 and 2 Hbs are full-length globins with the classical eight helix Mb-like fold, whereas Class 3 plant Hbs resemble the truncated globins found in bacteria. With the exception of the specialized leghemoglobins, the physiological functions of these plant hemoglobins remain unknown. We have reviewed and, in some cases, measured new oxygen binding properties of a large number of Class 1 and 2 plant nonsymbiotic Hbs and leghemoglobins. We found that sequence classification correlates with distinct extents of hexacoordination with the distal histidine and markedly different overall oxygen affinities and association and dissociation rate constants. These results suggest strong selective pressure for the evolution of distinct physiological functions. The leghemoglobins evolved from the Class 2 globins and show no hexacoordination, very high rates of O(2) binding ( approximately 250 muM(-1) s(-1)), moderately high rates of O(2) dissociation ( approximately 5-15 s(-1)), and high oxygen affinity (K(d) or P(50) approximately 50 nM). These properties both facilitate O(2) diffusion to respiring N(2) fixing bacteria and reduce O(2) tension in the root nodules of legumes. The Class 1 plant Hbs show weak hexacoordination (K(HisE7) approximately 2), moderate rates of O(2) binding ( approximately 25 muM(-1) s(-1)), very small rates of O(2) dissociation ( approximately 0.16 s(-1)), and remarkably high O(2) affinities (P(50) approximately 2 nM), suggesting a function involving O(2) and nitric oxide (NO) scavenging. The Class 2 Hbs exhibit strong hexacoordination (K(HisE7) approximately 100), low rates of O(2) binding ( approximately 1 muM(-1) s(-1)), moderately low O(2) dissociation rate constants ( approximately 1 s(-1)), and moderate, Mb-like O(2) affinities (P(50) approximately 340 nM), perhaps suggesting a sensing role for sustained low, micromolar levels of oxygen.
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Affiliation(s)
- Benoit J Smagghe
- Department of Biochemistry, Iowa State University, Ames, IA 50011, USA
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Dordas C. Nonsymbiotic hemoglobins and stress tolerance in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2009; 176:433-40. [PMID: 26493132 DOI: 10.1016/j.plantsci.2009.01.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 01/09/2009] [Accepted: 01/09/2009] [Indexed: 05/24/2023]
Abstract
Hemoglobins (Hbs) are heme containing proteins found in most organisms including animals, bacteria, and plants. Their structure, size, and function are quite diverse among the different organisms. There are three different types of hemoglobins in plants: symbiotic (sHb), nonsymbiotic (nsHb), and truncated hemoglobins (trHb). The nonsymbiotic hemoglobins are divided into: class 1 hemoglobins (nsHb-1s), which have a very high affinity for oxygen: and class 2 hemoglobins (nsHb-2s), which have lower affinity for oxygen, are similar to the sHbs. nsHb-1s are expressed under hypoxia, osmotic stress, nutrient deprivation, cold stress, rhizobial infection, nitric oxide exposure, and fungal infection. Tolerance to stress is very important for the survival of the plant. Hemoglobins are one of many different strategies that plants have evolved to overcome stress conditions and survive. Hbs also react with NO produced under different stress conditions. Class 1 nsHbs are involved in a metabolic pathway involving NO. Those hemoglobins provide an alternative type of respiration to mitochondrial electron transport under limiting oxygen concentrations. Class 1 nsHbs in hypoxic plants act as part of a soluble, terminal, NO dioxygenase system, yielding nitrate from the reaction of oxyHb with NO. The overall reaction sequence, referred to as the nsHb/NO cycle, consumes NADH and maintains ATP levels via an as yet unknown mechanism. Class 2 nsHbs seem to scavenge NO in a similar fashion as class 1 Hbs and are involved in reducing flowering time in Arabidopsis. nsHbs also show peroxidase-like activity and NO metabolism and possibly protect against nitrosative stress in plant-pathogen interaction and in symbiotic interactions. nsHbs may be involved in other stress conditions such as osmotic, nutrient and cold stress together with NO and the function of nsHbs can be in NO metabolism and signal transduction. However, other possible functions cannot be precluded as Hbs have many different functions in other organisms.
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Affiliation(s)
- Christos Dordas
- Aristotle University of Thessaloniki, Faculty of Agriculture, Laboratory of Agronomy, 54124 Thessaloniki, Greece.
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Ungerman AJ, Heindel TJ. Carbon Monoxide Mass Transfer for Syngas Fermentation in a Stirred Tank Reactor with Dual Impeller Configurations. Biotechnol Prog 2008; 23:613-20. [PMID: 17326659 DOI: 10.1021/bp060311z] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study compares the power demand and gas-liquid volumetric mass transfer coefficient, kLa, in a stirred tank reactor (STR) (T = 0.211 m) using different impeller designs and schemes in a carbon monoxide-water system, which is applicable to synthesis gas (syngas) fermentation. Eleven different impeller schemes were tested over a range of operating conditions typically associated with the "after large cavity" region (ALC) of a Rushton-type turbine (D/T = 0.35). It is found that the dual Rushton-type impeller scheme exhibits the highest volumetric mass transfer rates for all operating conditions; however, it also displays the lowest mass transfer performance (defined as the volumetric mass transfer coefficient per unit power input) for all conditions due to its high power consumption. Dual impeller schemes with an axial flow impeller as the top impeller show improved mass transfer rates without dramatic increases in power draw. At high gas flow rates, dual impeller schemes with a lower concave impeller have kLa values similar to those of the Rushton-type dual impeller schemes but show improved mass transfer performance. It is believed that the mass transfer performance can be further enhanced for the bottom concave impeller schemes by operating at conditions beyond the ALC region defined for Rushton-type impellers because the concave impeller can handle higher gas flow rates prior to flooding.
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Affiliation(s)
- Andrew J Ungerman
- Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA
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Smagghe BJ, Halder P, Hargrove MS. Measurement of distal histidine coordination equilibrium and kinetics in hexacoordinate hemoglobins. Methods Enzymol 2008; 436:359-78. [PMID: 18237643 DOI: 10.1016/s0076-6879(08)36020-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
The kinetics of ligand binding to hemoglobins has been measured for decades. Initially, these studies were confined to readily available pentacoordinate oxygen transport proteins like myoglobin, leghemoglobin, and red blood cell hemoglobin. Bimolecular ligand binding to these proteins is relatively simple, as ligand association is largely unimpeded at the heme iron. Although many techniques have been used to examine these reactions in the past, stopped-flow rapid mixing and flash photolysis are the most common ways to measure rate constants for ligand association and dissociation. Expression of recombinant proteins has allowed for examination of many newly discovered hemoglobins. The hexacoordinate hemoglobins are one such group of proteins that exhibit more complex binding kinetics than pentacoordinate hemoglobins due to reversible intramolecular coordination by a histidine side chain. Here, we describe methods for characterizing the kinetics of ligand binding to hexacoordinate hemoglobins with a focus on measurement of histidine coordination and exogenous ligand binding in both the ferrous and the ferric oxidation states.
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Affiliation(s)
- Benoit J Smagghe
- Immune Disease Institute, Harvard Medical School, Boston, Massachusetts
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31
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Hoy JA, Hargrove MS. The structure and function of plant hemoglobins. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2008; 46:371-9. [PMID: 18321722 DOI: 10.1016/j.plaphy.2007.12.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Indexed: 05/24/2023]
Abstract
Plants, like humans, contain hemoglobin. Three distinct types of hemoglobin exist in plants: symbiotic, non-symbiotic, and truncated hemoglobins. Crystal structures and other structural and biophysical techniques have revealed important knowledge about ligand binding and conformational stabilization in all three types. In symbiotic hemoglobins (leghemoglobins), ligand binding regulatory mechanisms have been shown to differ dramatically from myoglobin and red blood cell hemoglobin. In the non-symbiotic hemoglobins found in all plants, crystal structures and vibrational spectroscopy have revealed the nature of the structural transition between the hexacoordinate and ligand-bound states. In truncated hemoglobins, the abbreviated globin is porous, providing tunnels that may assist in ligand binding, and the bound ligand is stabilized by more than one distal pocket residue. Research has implicated these plant hemoglobins in a number of possible functions differing among hemoglobin types, and possibly between plant species.
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Affiliation(s)
- Julie A Hoy
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50014, USA
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32
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Farrés J, Burckhardt-Herold S, Scherrer J, Frey A, Kallio P. Analysis of the contribution of the globin and reductase domains to the ligand-binding properties of bacterial haemoglobins. Biochem J 2007; 407:15-22. [PMID: 17617059 PMCID: PMC2267399 DOI: 10.1042/bj20070668] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacterial Hbs (haemoglobins), like VHb (Vitreoscilla sp. Hb), and flavoHbs (flavohaemoglobins), such as FHP (Ralstonia eutropha flavoHb), have different autoxidation and ligand-binding rates. To determine the influence of each domain of flavoHbs on ligand binding, we have studied the kinetic ligand-binding properties of oxygen, carbon monoxide and nitric oxide to the chimaeric proteins, FHPg (truncated form of FHP comprising the globin domain alone) and VHb-Red (fusion protein between VHb and the C-terminal reductase domain of FHP) and compared them with those of their natural counterparts, FHP and VHb. Moreover, we also analysed polarity and solvent accessibility to the haem pocket of these proteins. The rate constants for the engineered proteins, VHb-Red and FHPg, do not differ significantly from those of their natural counterparts, VHb and FHP respectively. Our results suggest that the globin domain structure controls the reactivity towards oxygen, carbon monoxide and nitric oxide. The presence or absence of a reductase domain does not affect the affinity to these ligands.
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Affiliation(s)
- Judith Farrés
- *Institute of Biotechnology, ETH Zürich, CH 8093 Zürich, Switzerland
| | | | - Jan Scherrer
- *Institute of Biotechnology, ETH Zürich, CH 8093 Zürich, Switzerland
| | | | - Pauli T. Kallio
- ‡Institute of Microbiology, ETH Zürich, CH 8093 Zürich, Switzerland
- To whom correspondence should be addressed (email )
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Yucel MA, Kurnaz IA. An in silico model for HIF-alpha regulation and hypoxia response in tumor cells. Biotechnol Bioeng 2007; 97:588-600. [PMID: 17089387 DOI: 10.1002/bit.21247] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The dependency of the growth and metastasis of tumors on the new blood vessel formation, or angiogenesis, has opened up new potentials to tumor therapy, nevertheless understanding the molecular mechanisms involved in angiogenesis is crucial in the bioengineering of novel anti-angiogenic drugs. The key component in hypoxia sensing in tumor cells is the hypoxia-inducible factor, HIF-1alpha, which is inactivated through proteosome-mediated degradation under normoxic conditions. Two enzymes have been reported to hydroxylate HIF-1alpha, namely prolyl hydroxylase (PH), recruiting the proetasome complex and degrading cytoplasmic HIF-1alpha, and asparaginyl hydroxylase/factor inhibiting HIF-1alpha (FIH-1), downregulating the recruitment of p300 to the promoter, thereby reducing the transcriptional activity of HIF-1alpha. In this study, we have constructed an in silico model of a tumor cell using the GEPASI 3.30 biochemical simulation software (http://www.gepasi.org) and studied the performances of PH and FIH-1 on HIF-1alpha degradation and inactivation, respectively, as monitored by expression of the vascular endothelial growth factor, VEGF, during hypoxia. In our biochemical models, FIH-1 can successfully increase hypoxic transcription of VEGF, however FIH-1 on its own is not sufficient to inactivate HIF-1 completely, leading to background VEGF transcription under normoxic conditions. On the other hand, PH is necessary to increase the hypoxic transcriptional response, and can effectively shut off normoxic transcription. We therefore propose that regulating PH activity can be a primary target for anti-angiogenic bioengineering research.
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Affiliation(s)
- Meryem A Yucel
- Bogazici University, Institute of Biomedical Engineering, Bebek, Istanbul, Turkey
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Hoy JA, Smagghe BJ, Halder P, Hargrove MS. Covalent heme attachment in Synechocystis hemoglobin is required to prevent ferrous heme dissociation. Protein Sci 2007; 16:250-60. [PMID: 17242429 PMCID: PMC2203299 DOI: 10.1110/ps.062572607] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Synechocystis hemoglobin contains an unprecedented covalent bond between a nonaxial histidine side chain (H117) and the heme 2-vinyl. This bond has been previously shown to stabilize the ferric protein against denaturation, and also to affect the kinetics of cyanide association. However, it is unclear why Synechocystis hemoglobin would require the additional degree of stabilization accompanying the His117-heme 2-vinyl bond because it also displays endogenous bis-histidyl axial heme coordination, which should greatly assist heme retention. Furthermore, the mechanism by which the His117-heme 2-vinyl bond affects ligand binding has not been reported, nor has any investigation of the role of this bond on the structure and function of the protein in the ferrous oxidation state. Here we report an investigation of the role of the Synechocystis hemoglobin His117-heme 2-vinyl bond on structure, heme coordination, exogenous ligand binding, and stability in both the ferrous and ferric oxidation states. Our results reveal that hexacoordinate Synechocystis hemoglobin lacking this bond is less stable in the ferrous oxidation state than the ferric, which is surprising in light of our understanding of pentacoordinate Hb stability, in which the ferric protein is always less stable. It is also demonstrated that removal of the His117-heme 2-vinyl bond increases the affinity constant for intramolecular histidine coordination in the ferric oxidation state, thus presenting greater competition for the ligand binding site and lowering the observed rate and affinity constants for exogenous ligands.
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Affiliation(s)
- Julie A Hoy
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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35
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Bonamore A, Attili A, Arenghi F, Catacchio B, Chiancone E, Morea V, Boffi A. A novel chimera: the "truncated hemoglobin-antibiotic monooxygenase" from Streptomyces avermitilis. Gene 2007; 398:52-61. [PMID: 17574781 DOI: 10.1016/j.gene.2007.01.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 01/24/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Novel chimeric proteins made of a globin domain fused with a "cofactor free" monooxygenase domain have been identified within the Streptomyces avermitilis and Frankia sp. genomes by means of bioinformatics methods. Structure based sequence alignments show that the globin domains of both proteins can be unambiguously assigned to the truncated hemoglobin family, in view of the striking similarity to the truncated hemoglobins from Mycobacterium tuberculosis, Thermobifida fusca and Bacillus subtilis. In turn, the non-heme domains belong to a family of small (about 100 aminoacids) homodimeric proteins annotated as antibiotic biosynthesis monooxygenases, despite the lack of a cofactor (e.g., a metal, a flavin or a heme) necessary for oxygen activation. The chimeric protein from S. avermitilis has been cloned, expressed and characterized. The protein is a stable dimer in solution based on analytical ultracentrifugation experiments. The heme ligand binding properties with oxygen and carbonmonoxide resemble those of other Group II truncated hemoglobins. In addition, an oxygen dependent redox activity has been demonstrated towards easily oxidizable substrates such as menadiol and p-aminophenol. These findings suggest novel functional roles of truncated hemoglobins, which might represent a vast class of multipurpose oxygen activating/scavenging proteins whose catalytic action is mediated by the interaction with cofactor free monooxygenases.
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Affiliation(s)
- Alessandra Bonamore
- Department of Biochemical Sciences, University of Rome La Sapienza, P.le Aldo Moro 5, 00185 Rome, Italy
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Halder P, Trent JT, Hargrove MS. Influence of the protein matrix on intramolecular histidine ligation in ferric and ferrous hexacoordinate hemoglobins. Proteins 2007; 66:172-82. [PMID: 17044063 DOI: 10.1002/prot.21210] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Present in most organisms, hexacoordinate hemoglobins (hxHbs) are proteins that have evolved the capacity for reversible bis-histidyl heme coordination. The heme prosthetic group enables diverse protein functionality, such as electron transfer, redox reactions, ligand transport, and enzymatic catalysis. The reactivity of heme is greatly effected by the coordination and noncovalent chemical environment imposed by its connate protein. Of considerable interest is how the hxHb globin fold achieves reversible intramolecular coordination while still enabling high-affinity binding of oxygen, nitric oxide, and other small ligands. Here we explore this question by examining the role of the protein matrix on coordination behavior in a group of hxHbs from animals, plants, and bacteria, including human neuroglobin and cytoglobin, a nonsymbiotic hemoglobin from rice, and a truncated hemoglobin from the cyanobacterium Synechocystis. This is done with a set of experiments measuring the reduction potentials of each wild-type hxHb and its corresponding mutant protein where the reversibly bound histidine (the distal His) has been replaced with a noncoordinating side chain. These reduction potentials, coupled with studies of the mutant proteins saturated with exogenous imidazole, enable us to assess the effects of the protein matrices on histidine coordination. Our results show significant variation among the hxHbs, demonstrating flexibility in the globin moiety's ability to regulate reversible coordination. This regulation is particularly evident in the plant nonsymbiotic hemoglobins, where ferric state histidine coordination affinity is substantially lowered by the protein matrix.
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Affiliation(s)
- Puspita Halder
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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Pavlov VY. Modern aspects of the Chemistry of protoporphyrin IX. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2007. [DOI: 10.1134/s1070428007010010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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38
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Smagghe BJ, Blervacq AS, Blassiau C, Decottignies JP, Jacquot JP, Hargrove MS, Hilbert JL. Immunolocalization of non-symbiotic hemoglobins during somatic embryogenesis in chicory. PLANT SIGNALING & BEHAVIOR 2007; 2:43-9. [PMID: 19516967 PMCID: PMC2633897 DOI: 10.4161/psb.2.1.3812] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Accepted: 12/23/2006] [Indexed: 05/19/2023]
Abstract
Hemoglobins are ancient O(2)-binding proteins, ubiquitously found in eukaryotes. They have been categorized as symbiotic, nonsymbiotic and truncated hemoglobins. We have investigated the cellular localization of nonsymbiotic hemoglobin proteins during somatic embryogenesis in Cichorium hybrid leaves (Cichorium intybus L. var. sativum x C. endivia var. latifolia) using immunolocalization technique. These proteins were detected during the two steps of culture: induction and expression. In leaves, hemoglobins colocalised with plastids, which were dispersed in the parietal cytoplasm as well as in the two guard cells of a stomata, but not in epidermis cells. Upon induction of embryogenesis, in the dark, this pattern disappeared. During the induction phase, where competent cells reinitiate the cell cycle and prepare for mitosis, hemoglobins appeared initially near chloroplasts, and then in the vicinity of vascular vessels especially in the phloem and in cells surrounding the xylem vessels. When leaf fragments were transferred to another medium for the expression phase, hemoglobins were observed in the majority of the leaf blade cells and in small young embryos but not in the older ones. Hemoglobins were also detected in other leaves cells or tissues all along the process. The role of these nonsymbiotic hemoglobins during somatic embryogenesis is discussed.
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Affiliation(s)
- Benoît J Smagghe
- Université des Sciences et Technologies de Lille; “Stress Abiotiques et Différenciation des Végétaux Cultivés”
- Department of Biochemistry; Biophysics and Molecular Biology; Iowa State University; Ames, Iowa USA
| | - Anne-Sophie Blervacq
- Université des Sciences et Technologies de Lille; “Stress Abiotiques et Différenciation des Végétaux Cultivés”
| | - Christelle Blassiau
- Université des Sciences et Technologies de Lille; “Stress Abiotiques et Différenciation des Végétaux Cultivés”
| | | | - Jean-Pierre Jacquot
- Université Henri Poincaré; Laboratoire Interaction Arbres Microorganismes; Vandoeuvre, Cedex, France
| | - Mark S Hargrove
- Department of Biochemistry; Biophysics and Molecular Biology; Iowa State University; Ames, Iowa USA
| | - Jean-Louis Hilbert
- Université des Sciences et Technologies de Lille; “Stress Abiotiques et Différenciation des Végétaux Cultivés”
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39
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Ilari A, Kjelgaard P, von Wachenfeldt C, Catacchio B, Chiancone E, Boffi A. Crystal structure and ligand binding properties of the truncated hemoglobin from Geobacillus stearothermophilus. Arch Biochem Biophys 2007; 457:85-94. [PMID: 17126283 DOI: 10.1016/j.abb.2006.09.033] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 09/14/2006] [Accepted: 09/15/2006] [Indexed: 11/22/2022]
Abstract
A novel truncated hemoglobin has been identified in the thermophilic bacterium Geobacillus stearothermophilus (Gs-trHb). The protein has been expressed in Escherichia coli, the 3D crystal structure (at 1.5 Angstroms resolution) and the ligand binding properties have been determined. The distal heme pocket displays an array of hydrogen bonding donors to the iron-bound ligands, including Tyr-B10 on one side of the heme pocket and Trp-G8 indole nitrogen on the opposite side. At variance with the highly similar Bacillus subtilis hemoglobin, Gs-trHb is dimeric both in the crystal and in solution and displays several unique structural properties. In the crystal cell, the iron-bound ligand is not homogeneously distributed within each distal site such that oxygen and an acetate anion can be resolved with relative occupancies of 50% each. Accordingly, equilibrium titrations of the oxygenated derivative in solution with acetate anion yield a partially saturated ferric acetate adduct. Moreover, the asymmetric unit contains two subunits and sedimentation velocity ultracentrifugation data confirm that the protein is dimeric.
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Affiliation(s)
- Andrea Ilari
- Department of Biochemical Sciences and CNR Institute of Molecular Biology and Pathology, University of Rome La Sapienza, P le Aldo Moro 5, 00185 Rome, Italy
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40
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Kapic A, Jones ST, Heindel TJ. Carbon Monoxide Mass Transfer in a Syngas Mixture. Ind Eng Chem Res 2006. [DOI: 10.1021/ie060655u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amir Kapic
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, Iowa 50011
| | - Samuel T. Jones
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, Iowa 50011
| | - Theodore J. Heindel
- Department of Mechanical Engineering, 2025 Black Engineering Building, Iowa State University, Ames, Iowa 50011
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41
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Rinaldi AC, Bonamore A, Macone A, Boffi A, Bozzi A, Di Giulio A. Interaction of Vitreoscilla Hemoglobin with Membrane Lipids. Biochemistry 2006; 45:4069-76. [PMID: 16566580 DOI: 10.1021/bi052277n] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of the recombinant hemoglobin from Vitreoscilla sp. (VHb) with the bacterial membrane of Escherichia coli cells has been investigated by measuring the propensity of VHb to interact with monolayers formed by natural bacterial phosholipids. The measurements showed that the protein is capable of penetrating the monolayers, possibly establishing interactions with the hydrophobic acyl chains. VHb is also capable of binding reversibly phospholipids and free fatty acids in solution with a strong selectivity toward cyclopropanated acyl chain species. Lipid binding occurs within the distal heme pocket as demonstrated by a sharp UV-vis spectral change corresponding to a five-coordinate to six-coordinate transition of the heme-iron ferric derivative. Oxygen binding properties are affected by the presence of the lipid component within the active site. In particular, the oxygen affinity is decreased by more than 20-fold in the presence of cyclopropanated phospholipids. The kinetic counterpart of the decrease in oxygen affinity is manifest in a 10-fold decrease in the ligand combination kinetics. Accordingly, the CO and NO combination kinetics were also significantly affected by the presence of the bound lipid within the active site. These studies indicate that the current functional hypotheses about VHb should take into account the association of the protein within the cytoplasmic membrane as well as the presence of a phospholipid within the active site. These data suggest a possible lipid-induced regulation of oxygen affinity as the basis of VHb functioning.
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Affiliation(s)
- Andrea C Rinaldi
- Dipartimento di Scienze e Tecnologie Biomediche, Sezione di Chimica Biologica e Biotecnologie Biochimiche, Università di Cagliari, I-09042 Monserrato (CA), Italy
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42
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Smagghe BJ, Sarath G, Ross E, Hilbert JL, Hargrove MS. Slow Ligand Binding Kinetics Dominate Ferrous Hexacoordinate Hemoglobin Reactivities and Reveal Differences between Plants and Other Species. Biochemistry 2005; 45:561-70. [PMID: 16401085 DOI: 10.1021/bi051902l] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hexacoordinate hemoglobins are found in many living organisms ranging from prokaryotes to plants and animals. They are named "hexacoordinate" because of reversible coordination of the heme iron by a histidine side chain located in the heme pocket. This endogenous coordination competes with exogenous ligand binding and causes multiphasic relaxation time courses following rapid mixing or flash photolysis experiments. Previous rapid mixing studies have assumed a steady-state relationship between hexacoordination and exogenous ligand binding that does not correlate with observed time courses for binding. Here, we demonstrate that this assumption is not valid for some hexacoordinate hemoglobins, and that multiphasic time courses are due to an appreciable fraction of pentacoordinate heme resulting from relatively small equilibrium constants for hexacoordination (K(H)). CO binding reactions initiated by rapid mixing are measured for four plant hexacoordinate hemoglobins, human neuroglobin and cytoglobin, and Synechocystis hemoglobin. The plant proteins, while showing a surprising degree of variability, differ from the others in having much lower values of K(H). Neuroglobin and cytoglobin display dramatic biphasic time courses for CO binding that have not been observed using other techniques. Finally, an independent spectroscopic quantification of K(H) is presented that complements rapid mixing for the investigation of hexacoordination. These results demonstrate that hexacoordination could play a much larger role in regulating affinity constants for ligand binding in human neuroglobin and cytoglobin than in the plant hexacoordinate hemoglobins.
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Affiliation(s)
- Benoit J Smagghe
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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43
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Martí MA, Bikiel DE, Crespo A, Nardini M, Bolognesi M, Estrin DA. Two distinct heme distal site states define Cerebratulus lacteus mini-hemoglobin oxygen affinity. Proteins 2005; 62:641-8. [PMID: 16432879 DOI: 10.1002/prot.20822] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The nerve tissue hemoglobin of Cerebratulus lacteus (CerHb) is the smallest naturally occurring known hemoglobin. Stabilization of the diatomic bound species (e.g., O(2)) is achieved through a network of hydrogen bonds based on three key residues TyrB10, GlnE7, and ThrE11. The first two residues are typically associated in hemoglobins with enhanced O(2) affinity, related to hydrogen bond stabilization of the heme-bound O(2) resulting in a decrease of the ligand dissociation rates. In contrast to the above observations, the affinity of CerHb for O(2) is only moderate, and the rate of O(2) dissociation is unexpectedly high. To gain insight on the diverse molecular mechanisms controlling ligand affinities, we have analyzed w.t. CerHb and its ThrE11-->Val mutant by means of joint molecular dynamics and quantum mechanics simulation techniques, complementing recent site-directed mutagenesis experiments. Our results suggest that the observed O(2) dissociation rates can only be explained through a dynamic equilibrium between high and low affinity states of the w.t. CerHb heme distal site.
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Affiliation(s)
- Marcelo A Martí
- Departamento de Química Inorgnica, Analítica y Química Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
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44
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Bonamore A, Ilari A, Giangiacomo L, Bellelli A, Morea V, Boffi A. A novel thermostable hemoglobin from the actinobacterium Thermobifida fusca. FEBS J 2005; 272:4189-201. [PMID: 16098200 DOI: 10.1111/j.1742-4658.2005.04831.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The gene coding for a hemoglobin-like protein (Tf-trHb) has been identified in the thermophilic actinobacterium Thermobifida fusca and cloned in Escherichia coli for overexpression. The crystal structure of the ferric, acetate-bound derivative, was obtained at 2.48 A resolution. The three-dimensional structure of Tf-trHb is similar to structures reported for the truncated hemoglobins from Mycobacterium tuberculosis and Bacillus subtilis in its central domain. The complete lack of diffraction patterns relative to the N- and C-terminal segments indicates that these are unstructured polypeptides chains, consistent with their facile cleavage in solution. The absence of internal cavities and the presence of two water molecules between the bound acetate ion and the protein surface suggest that the mode of ligand entry is similar to that of typical hemoglobins. The protein is characterized by higher thermostability than the similar mesophilic truncated hemoglobin from B. subtilis, as demonstrated by far-UV CD melting experiments on the cyano-met derivatives. The ligand-binding properties of Tf-trHb, analyzed in stopped flow experiments, demonstrate that Tf-trHb is capable of efficient O2 binding and release between 55 and 60 degrees C, the optimal growth temperature for Thermobifida fusca.
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45
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Abstract
How do plants create an environment in which symbiotic bacteria can reduce enough N2 to provide the plant with sufficient ammonium for growth? Gene silencing has now been used to show that legume haemoglobins are crucial.
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Affiliation(s)
- J Allan Downie
- Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK.
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46
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Perazzolli M, Dominici P, Romero-Puertas MC, Zago E, Zeier J, Sonoda M, Lamb C, Delledonne M. Arabidopsis nonsymbiotic hemoglobin AHb1 modulates nitric oxide bioactivity. THE PLANT CELL 2004; 16:2785-94. [PMID: 15367716 PMCID: PMC520971 DOI: 10.1105/tpc.104.025379] [Citation(s) in RCA: 236] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Accepted: 07/29/2004] [Indexed: 05/17/2023]
Abstract
Nitric oxide (NO) is a widespread signaling molecule, and numerous targets of its action exist in plants. Whereas the activity of NO in erythrocytes, microorganisms, and invertebrates has been shown to be regulated by several hemoglobins, the function of plant hemoglobins in NO detoxification has not yet been elucidated. Here, we show that Arabidopsis thaliana nonsymbiotic hemoglobin AHb1 scavenges NO through production of S-nitrosohemoglobin and reduces NO emission under hypoxic stress, indicating its role in NO detoxification. However, AHb1 does not affect NO-mediated hypersensitive cell death in response to avirulent Pseudomonas syringae, suggesting that it is not involved in the removal of NO bursts originated from acute responses when NO mediates crucial defense signaling functions.
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Affiliation(s)
- Michele Perazzolli
- Dipartimento Scientifico e Tecnologico, Università degli Studi di Verona, 37134 Verona, Italy
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47
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Kwon SJ, Petri R, DeBoer AL, Schmidt-Dannert C. A High-Throughput Screen for Porphyrin Metal Chelatases: Application to the Directed Evolution of Ferrochelatases for Metalloporphyrin Biosynthesis. Chembiochem 2004; 5:1069-74. [PMID: 15300829 DOI: 10.1002/cbic.200400051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Porphyrins are of particular interest in a variety of applications ranging from biocatalysis and chemical synthesis to biosensor and electronic technologies as well as cancer treatment. Recently, we have developed a versatile system for the high-level production of porphyrins in engineered E. coli cells with the aim of diversifying substitution patterns and accessing porphyrin systems not readily available through chemical synthesis. However, this approach failed to produce significant amounts of the metalloporphyrin in vivo from overproduced protoporphyrin due to insufficient metal insertion. Therefore, we systematically assessed the activity of the B. subtilis ferrochelatase in vivo and in vitro. A true high-throughput-screening approach based on catalytic in vivo ferrochelatase activity was developed by using fluorescence-activated cell sorting (FACS). This assay was used to screen a library of 2.4 x 10(6) ferrochelatase mutants expressed in protoporphyrin-overproducing recombinant E. coli cells. Several selected protein variants were purified, and their improved catalytic activity was confirmed in vitro. In addition to ferrochelatase activity, metal transport into E. coli was identified as another limitation for in vivo heme overproduction. Overexpression of the metal transporter zupT as part of the assembled pathway increased the overall metalloporphyrin production twofold. This report represents the most exhaustive in vitro evolution study of a ferrochelatase and demonstrates the effectiveness of our novel high-throughput-screening system for directed evolution of ferrochelatases based on their catalytic activity.
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Affiliation(s)
- Seok Joon Kwon
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 1479 Gortner Avenue, Saint Paul, MN 55108, USA
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48
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Seregélyes C, Igamberdiev AU, Maassen A, Hennig J, Dudits D, Hill RD. NO-degradation by alfalfa class 1 hemoglobin (Mhb1): a possible link to PR-1a gene expression in Mhb1-overproducing tobacco plants. FEBS Lett 2004; 571:61-6. [PMID: 15280018 DOI: 10.1016/j.febslet.2004.06.055] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Revised: 06/23/2004] [Accepted: 06/23/2004] [Indexed: 10/26/2022]
Abstract
Tobacco plants overproducing alfalfa class 1 hemoglobin (HOT plants) have been shown to have reduced necrotic symptom development. Here, we show that this altered pathogenic response is linked to a significant increase in the nitric oxide (NO)-affected pathogenesis-related (PR-1a) transcript accumulation in the transgenic plants. Homogenates of HOT transgenic seedlings were also found to have higher NO-scavenging activity than non-transformed ones. The NO-scavenging properties of recombinant alfalfa class1 hemoglobin have been examined. Recombinant Mhb1 (rMhb1) was produced in bacteria and purified using polyethylene glycol (10-25%) fractionation, chromatography on DEAE-Sephacel, and Phenyl Superose columns. After the final purification step, the obtained preparations were near homogeneous and had a molecular weight of 44 kDa determined by size-exclusion chromatography and 23 kDa by SDS-PAGE, indicating that rMhb1 is a dimer. The protein participated in NO-degradation activity with NAD(P)H as a cofactor. After ion-exchange columns, addition of FAD was necessary for exhibiting maximal NO-degradation activity. The NAD(P)H-dependent NO-scavenging activity of rMhb1, which is similar to that of barley hemoglobin, supports a conclusion that both monocot and dicot class 1 hemoglobins can affect cellular NO levels by scavenging NO formed during hypoxia, pathogen attack and other stresses.
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Affiliation(s)
- Csaba Seregélyes
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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49
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Pesce A, Nardini M, Ascenzi P, Geuens E, Dewilde S, Moens L, Bolognesi M, Riggs AF, Hale A, Deng P, Nienhaus GU, Olson JS, Nienhaus K. Thr-E11 regulates O2 affinity in Cerebratulus lacteus mini-hemoglobin. J Biol Chem 2004; 279:33662-72. [PMID: 15161908 DOI: 10.1074/jbc.m403597200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mini-hemoglobin from Cerebratulus lacteus (CerHb) belongs to a class of globins containing the polar Tyr-B10/Gln-E7 amino acid pair that normally causes low rates of O2 dissociation and ultra-high O2 affinity, which suggest O2 sensing or NO scavenging functions. CerHb, however, has high rates of O2 dissociation (kO2 = 200-600 s(-1)) and moderate O2 affinity (KO2) approximately 1 microm(-1)) as a result of a third polar amino acid in its active site, Thr-E11. When Thr-E11 is replaced by Val, kO2 decreases 1000-fold and KO2 increases 130-fold at pH 7.0, 20 degrees C. The mutation also shifts the stretching frequencies of both heme-bound and photodissociated CO, indicating marked changes of the electrostatic field at the active site. The crystal structure of Thr-E11 --> Val CerHbO2 at 1.70 A resolution is almost identical to that of the wild-type protein (root mean square deviation of 0.12 A). The dramatic functional and spectral effects of the Thr-E11 --> Val mutation are due exclusively to changes in the hydrogen bonding network in the active site. Replacing Thr-E11 with Val "frees" the Tyr-B10 hydroxyl group to rotate toward and donate a strong hydrogen bond to the heme-bound ligand, causing a selective increase in O2 affinity, a decrease of the rate coefficient for O2 dissociation, a 40 cm(-1) decrease in nuCO of heme-bound CO, and an increase in ligand migration toward more remote intermediate sites.
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Affiliation(s)
- Alessandra Pesce
- Department of Physics-INFM and Center for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, 16146 Genova, Italy
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50
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Hoy JA, Kundu S, Trent JT, Ramaswamy S, Hargrove MS. The Crystal Structure of Synechocystis Hemoglobin with a Covalent Heme Linkage. J Biol Chem 2004; 279:16535-42. [PMID: 14736872 DOI: 10.1074/jbc.m313707200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The x-ray crystal structure of Synechocystis hemoglobin has been solved to a resolution of 1.8 A. The conformation of this structure is surprisingly different from that of the previously reported solution structure, probably due in part to a covalent linkage between the heme 2-vinyl and His117 that is present in the crystal structure but not in the structure solved by NMR. Synechocystis hemoglobin is a hexacoordinate hemoglobin in which the heme iron is coordinated by both the proximal and distal histidines. It is also a member of the "truncated hemoglobin" family that is much shorter in primary structure than vertebrate and plant hemoglobins. In contrast to other truncated hemoglobins, the crystal structure of Synechocystis hemoglobin displays no "ligand tunnel" and shows that several important amino acid side chains extrude into the solvent instead of residing inside the heme pocket. The stereochemistry of hexacoordination is compared with other hexacoordinate hemoglobins and cytochromes in an effort to illuminate factors contributing to ligand affinity in hexacoordinate hemoglobins.
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Affiliation(s)
- Julie A Hoy
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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