1
|
Ding C, Ding Z, Liu Q, Liu W, Chai L. Advances in mechanism for the microbial transformation of heavy metals: implications for bioremediation strategies. Chem Commun (Camb) 2024; 60:12315-12332. [PMID: 39364540 DOI: 10.1039/d4cc03722g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2024]
Abstract
Heavy metals are extensively discharged through various anthropogenic activities, resulting in an environmental risk on a global scale. In this case, microorganisms can survive in an extreme heavy metal-contaminated environment via detoxification or resistance, playing a pivotal role in the speciation, bioavailability, and mobility of heavy metals. Therefore, studies on the mechanism for the microbial transformation of heavy metals are of great importance and can provide guidance for heavy metal bioremediation. Current research studies on the microbial transformation of heavy metals mainly focus on the single oxidation, reduction and methylation pathways. However, complex microbial transformation processes and corresponding bioremediation strategies have never been clarified, which may involve the inherent physicochemical properties of heavy metals. To uncover the underlying mechanism, we reclassified heavy metals into three categories based on their biological transformation pathways, namely, metals that can be chelated, reduced or oxidized, and methylated. Firstly, we comprehensively characterized the difference in transmembrane pathways between heavy metal cations and anions. Further, biotransformation based on chelation by low-molecular-weight organic complexes is thoroughly discussed. Moreover, the progress and knowledge gaps in the microbial redox and (de)methylation mechanisms are discussed to establish a connection linking theoretical advancements with solutions to the heavy metal contamination problem. Finally, several efficient bioremediation strategies for heavy metals and the limitations of bioremediation are proposed. This review presents a solid contribution to the design of efficient microbial remediation strategies applied in the real environment.
Collapse
Affiliation(s)
- Chunlian Ding
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China.
| | - Zihan Ding
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China.
| | - Qingcai Liu
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China.
| | - Weizao Liu
- College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China.
| | - Liyuan Chai
- Institute of Environmental Science and Engineering, School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| |
Collapse
|
2
|
Ferreira MR, Morgado L, Salgueiro CA. Periplasmic electron transfer network in Geobacter sulfurreducens revealed by biomolecular interaction studies. Protein Sci 2024; 33:e5082. [PMID: 38935664 PMCID: PMC11210610 DOI: 10.1002/pro.5082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/29/2024]
Abstract
Multiheme cytochromes located in different compartments are crucial for extracellular electron transfer in the bacterium Geobacter sulfurreducens to drive important environmental processes and biotechnological applications. Recent studies have unveiled that for particular sets of electron terminal acceptors, discrete respiratory pathways selectively recruit specific cytochromes from both the inner and outer membranes. However, such specificity was not observed for the abundant periplasmic cytochromes, namely the triheme cytochrome family PpcA-E. In this work, the distinctive NMR spectroscopic signatures of these proteins in different redox states were explored to monitor pairwise interactions and electron transfer reactions between each pair of cytochromes. The results showed that the five proteins interact transiently and can exchange electrons between each other revealing intra-promiscuity within the members of this family. This discovery is discussed in the light of the establishment of an effective electron transfer network by this pool of cytochromes. This network is advantageous to the bacteria as it enables the maintenance of the functional working potential redox range within the cells.
Collapse
Affiliation(s)
- Marisa R. Ferreira
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
| | - Leonor Morgado
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
| | - Carlos A. Salgueiro
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and TechnologyUniversidade NOVA de LisboaCaparicaPortugal
| |
Collapse
|
3
|
Li J, Han H, Chang Y, Wang B. The material-microorganism interface in microbial hybrid electrocatalysis systems. NANOSCALE 2023; 15:6009-6024. [PMID: 36912348 DOI: 10.1039/d3nr00742a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
This review presents a comprehensive summary of the material-microorganism interface in microbial hybrid electrocatalysis systems. Microbial hybrid electrocatalysis has been developed to combine the advantages of inorganic electrocatalysis and microbial catalysis. However, electron transfer at the interfaces between microorganisms and materials is a very critical issue that affects the efficiency of the system. Therefore, this review focuses on the electron transfer at the material-microorganism interface and the strategies for building efficient microorganism and material interfaces. We begin with a brief introduction of the electron transfer mechanism in both the bioanode and biocathode of bioelectrochemical systems to understand the material-microorganism interface. Next, we summarise the strategies for constructing efficient material-microorganism interfaces including material design and modification and bacterial engineering. We also discuss emerging studies on the bio-inorganic hybrid electrocatalysis system. Understanding the interface between electrode/active materials and the microorganisms, especially the electron transfer processes, could help to drive the evolution of material-microorganism hybrid electrocatalysis systems towards maturity.
Collapse
Affiliation(s)
- Jiyao Li
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), Beijing 100190, China.
| | - Hexing Han
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), Beijing 100190, China.
| | - Yanhong Chang
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
| | - Bin Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), Beijing 100190, China.
| |
Collapse
|
4
|
From iron to bacterial electroconductive filaments: Exploring cytochrome diversity using Geobacter bacteria. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214284] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
5
|
Making protons tag along with electrons. Biochem J 2021; 478:4093-4097. [PMID: 34871365 DOI: 10.1042/bcj20210592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
Every living cell needs to get rid of leftover electrons when metabolism extracts energy through the oxidation of nutrients. Common soil microbes such as Geobacter sulfurreducens live in harsh environments that do not afford the luxury of soluble, ingestible electron acceptors like oxygen. Instead of resorting to fermentation, which requires the export of reduced compounds (e.g. ethanol or lactate derived from pyruvate) from the cell, these organisms have evolved a means to anaerobically respire by using nanowires to export electrons to extracellular acceptors in a process called extracellular electron transfer (EET) [ 1]. Since 2005, these nanowires were thought to be pili filaments [ 2]. But recent studies have revealed that nanowires are composed of multiheme cytochromes OmcS [ 3, 4] and OmcZ [ 5] whereas pili remain inside the cell during EET and are required for the secretion of nanowires [ 6]. However, how electrons are passed to these nanowires remains a mystery ( Figure 1A). Periplasmic cytochromes (Ppc) called PpcA-E could be doing the job, but only two of them (PpcA and PpcD) can couple electron/proton transfer - a necessary condition for energy generation. In a recent study, Salgueiro and co-workers selectively replaced an aromatic with an aliphatic residue to couple electron/proton transfer in PpcB and PpcE (Biochem. J. 2021, 478 (14): 2871-2887). This significant in vitro success of their protein engineering strategy may enable the optimization of bioenergetic machinery for bioenergy, biofuels, and bioelectronics applications.
Collapse
|
6
|
Marzolf DR, McKenzie AM, O’Malley MC, Ponomarenko NS, Swaim CM, Brittain TJ, Simmons NL, Pokkuluri PR, Mulfort KL, Tiede DM, Kokhan O. Mimicking Natural Photosynthesis: Designing Ultrafast Photosensitized Electron Transfer into Multiheme Cytochrome Protein Nanowires. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E2143. [PMID: 33126541 PMCID: PMC7693585 DOI: 10.3390/nano10112143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 05/02/2023]
Abstract
Efficient nanomaterials for artificial photosynthesis require fast and robust unidirectional electron transfer (ET) from photosensitizers through charge-separation and accumulation units to redox-active catalytic sites. We explored the ultrafast time-scale limits of photo-induced charge transfer between a Ru(II)tris(bipyridine) derivative photosensitizer and PpcA, a 3-heme c-type cytochrome serving as a nanoscale biological wire. Four covalent attachment sites (K28C, K29C, K52C, and G53C) were engineered in PpcA enabling site-specific covalent labeling with expected donor-acceptor (DA) distances of 4-8 Å. X-ray scattering results demonstrated that mutations and chemical labeling did not disrupt the structure of the proteins. Time-resolved spectroscopy revealed three orders of magnitude difference in charge transfer rates for the systems with otherwise similar DA distances and the same number of covalent bonds separating donors and acceptors. All-atom molecular dynamics simulations provided additional insight into the structure-function requirements for ultrafast charge transfer and the requirement of van der Waals contact between aromatic atoms of photosensitizers and hemes in order to observe sub-nanosecond ET. This work demonstrates opportunities to utilize multi-heme c-cytochromes as frameworks for designing ultrafast light-driven ET into charge-accumulating biohybrid model systems, and ultimately for mimicking the photosynthetic paradigm of efficiently coupling ultrafast, light-driven electron transfer chemistry to multi-step catalysis within small, experimentally versatile photosynthetic biohybrid assemblies.
Collapse
Affiliation(s)
- Daniel R. Marzolf
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| | - Aidan M. McKenzie
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| | - Matthew C. O’Malley
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| | - Nina S. Ponomarenko
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA; (N.S.P.); (K.L.M.); (D.M.T.)
| | - Coleman M. Swaim
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| | - Tyler J. Brittain
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| | - Natalie L. Simmons
- Department of Biology, James Madison University, Harrisonburg, VA 22807, USA;
| | | | - Karen L. Mulfort
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA; (N.S.P.); (K.L.M.); (D.M.T.)
| | - David M. Tiede
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL 60439, USA; (N.S.P.); (K.L.M.); (D.M.T.)
| | - Oleksandr Kokhan
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA; (D.R.M.); (A.M.M.); (C.M.S.); (T.J.B.)
| |
Collapse
|
7
|
Ferreira MR, Salgueiro CA. Biomolecular Interaction Studies Between Cytochrome PpcA From Geobacter sulfurreducens and the Electron Acceptor Ferric Nitrilotriacetate (Fe-NTA). Front Microbiol 2018; 9:2741. [PMID: 30524391 PMCID: PMC6262392 DOI: 10.3389/fmicb.2018.02741] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/26/2018] [Indexed: 11/17/2022] Open
Abstract
Geobacter sulfurreducens bacterium exhibits an enormous respiratory versatility, including the utilization of several toxic and radioactive metals as electron acceptors. This versatility is also replicated in the capability of the most abundant cytochrome in G. sulfurreducens, the periplasmic triheme cytochrome PpcA, to reduce uranium, chromium and other metal ions. From all possible electron transfer pathways in G. sulfurreducens, those involved in the iron reduction are the best characterized to date. Previously, we provided structural evidence for the complex interface established between PpcA and the electron acceptor Fe(III)-citrate. However, genetic studies suggested that this acceptor is mainly reduced by outer membrane cytochomes. In the present work, we used UV-visible measurements to demonstrate that PpcA is able to directly reduce the electron acceptor ferric nitrilotriacetate (Fe-NTA), a more outer membrane permeable iron chelated form. In addition, the molecular interactions between PpcA and Fe-NTA were probed by Nuclear Magnetic Resonance (NMR) spectroscopy. The NMR spectra obtained for PpcA samples in the absence and presence of Fe-NTA showed that the interaction is reversible and encompasses a positively charged surface region located in the vicinity of the heme IV. Overall, the study elucidates the formation of an electron transfer complex between PpcA and a readily outer-membrane permeable iron chelated form. The structural and functional relationships obtained explain how a single cytochrome is designed to effectively interact with a wide range of G. sulfurreducens electron acceptors, a feature that can be explored for optimal bioelectrochemical applications.
Collapse
Affiliation(s)
- Marisa R Ferreira
- UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Carlos A Salgueiro
- UCIBIO-REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| |
Collapse
|
8
|
Dantas JM, Ferreira MR, Catarino T, Kokhan O, Pokkuluri PR, Salgueiro CA. Molecular interactions between Geobacter sulfurreducens triheme cytochromes and the redox active analogue for humic substances. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:619-630. [PMID: 29777686 DOI: 10.1016/j.bbabio.2018.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/09/2018] [Accepted: 05/15/2018] [Indexed: 01/17/2023]
Abstract
The bacterium Geobacter sulfurreducens can transfer electrons to quinone moieties of humic substances or to anthraquinone-2,6-disulfonate (AQDS), a model for the humic acids. The reduced form of AQDS (AH2QDS) can also be used as energy source by G. sulfurreducens. Such bidirectional utilization of humic substances confers competitive advantages to these bacteria in Fe(III) enriched environments. Previous studies have shown that the triheme cytochrome PpcA from G. sulfurreducens has a bifunctional behavior toward the humic substance analogue. It can reduce AQDS but the protein can also be reduced by AH2QDS. Using stopped-flow kinetic measurements we were able to demonstrate that other periplasmic members of the PpcA-family in G. sulfurreducens (PpcB, PpcD and PpcE) also showed the same behavior. The extent of the electron transfer is thermodynamically controlled favoring the reduction of the cytochromes. NMR spectra recorded for 13C,15N-enriched samples in the presence increasing amounts of AQDS showed perturbations in the chemical shift signals of the cytochromes. The chemical shift perturbations on cytochromes backbone NH and 1H heme methyl signals were used to map their interaction regions with AQDS, showing that each protein forms a low-affinity binding complex through well-defined positive surface regions in the vicinity of heme IV (PpcB, PpcD and PpcE) and I (PpcE). Docking calculations performed using NMR chemical shift perturbations allowed modeling the interactions between AQDS and each cytochrome at a molecular level. Overall, the results obtained provided important structural-functional relationships to rationalize the microbial respiration of humic substances in G. sulfurreducens.
Collapse
Affiliation(s)
- Joana M Dantas
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516 Caparica, Portugal
| | - Marisa R Ferreira
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516 Caparica, Portugal
| | - Teresa Catarino
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; Departamento de Química, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Oleksandr Kokhan
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, VA 22807, USA
| | - P Raj Pokkuluri
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Carlos A Salgueiro
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus Caparica, 2829-516 Caparica, Portugal.
| |
Collapse
|
9
|
Jiang H, Jin Q, Li J, Chen S, Zhang L, Liu M. Photoirradiation-generated radicals in two-component supramolecular gel for polymerization. SOFT MATTER 2018; 14:2295-2300. [PMID: 29498737 DOI: 10.1039/c8sm00153g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
While supramolecular gels have been attracting great interest due to their easy design and fabrication, development of new applications based on these gels is always a challenging topic. Here, we report a two-component supramolecular gel that can generate and stabilize radicals through photo-irradiation, which can be subsequently used for polymerization. It has been found that the electrostatic interactions between a cationic amphiphile and anionic sulfonate could afford co-assembly into a two-component supramolecular gel. Upon photo-irradiation, the gel changed colour and produced the radicals, as verified from the EPR measurements. The radical thus formed in the supramolecular gel is relatively stable and could be used to polymerize acrylic acid directly without deoxygenation. In contrast, acrylic acid could not be polymerized in solution under the same conditions. This work expands the application scope of supramolecular gels.
Collapse
Affiliation(s)
- Hejin Jiang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing 100190, China. and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingxian Jin
- Henan Provincial Key Laboratory of Surface & Interface Science, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, China
| | - Jing Li
- Henan Provincial Key Laboratory of Surface & Interface Science, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, China
| | - Shuyu Chen
- Henan Provincial Key Laboratory of Surface & Interface Science, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, China
| | - Li Zhang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing 100190, China.
| | - Minghua Liu
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing 100190, China. and University of Chinese Academy of Sciences, Beijing 100049, China and National Center for Nanoscience and Technology, Beijing, 100190, China and A Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| |
Collapse
|
10
|
Ponomarenko N, Niklas J, Pokkuluri PR, Poluektov O, Tiede DM. Electron Paramagnetic Resonance Characterization of the Triheme Cytochrome from Geobacter sulfurreducens. Biochemistry 2018; 57:1722-1732. [DOI: 10.1021/acs.biochem.7b00917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
11
|
Dantas JM, Brausemann A, Einsle O, Salgueiro CA. NMR studies of the interaction between inner membrane-associated and periplasmic cytochromes from Geobacter sulfurreducens. FEBS Lett 2017; 591:1657-1666. [PMID: 28542725 DOI: 10.1002/1873-3468.12695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 05/05/2017] [Accepted: 05/13/2017] [Indexed: 11/08/2022]
Abstract
Geobacter sulfurreducens is a dissimilatory metal-reducing bacterium with notable properties and significance in biotechnological applications. Biochemical studies suggest that the inner membrane-associated diheme cytochrome MacA and the periplasmic triheme cytochrome PpcA from G. sulfurreducens can exchange electrons. In this work, NMR chemical shift perturbation measurements were used to map the interface region and to measure the binding affinity between PpcA and MacA. The results show that MacA binds to PpcA in a cleft defined by hemes I and IV, favoring the contact between PpcA heme IV and the MacA high-potential heme. The dissociation constant values indicate the formation of a low-affinity complex between the proteins, which is consistent with the transient interaction observed in electron transfer complexes.
Collapse
Affiliation(s)
- Joana M Dantas
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Anton Brausemann
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, Freiburg, Germany
| | - Oliver Einsle
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, Freiburg, Germany
| | - Carlos A Salgueiro
- UCIBIO-Requimte, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| |
Collapse
|
12
|
Ferreira MR, Dantas JM, Salgueiro CA. Molecular interactions between Geobacter sulfurreducens triheme cytochromes and the electron acceptor Fe(iii) citrate studied by NMR. Dalton Trans 2017; 46:2350-2359. [DOI: 10.1039/c6dt04129a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular interactions betweenGeobacter sulfurreducenstriheme cytochromes and Fe(iii) citrate.
Collapse
Affiliation(s)
- Marisa R. Ferreira
- UCIBIO-Requimte
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade NOVA de Lisboa
- 2829-516 Caparica
| | - Joana M. Dantas
- UCIBIO-Requimte
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade NOVA de Lisboa
- 2829-516 Caparica
| | - Carlos A. Salgueiro
- UCIBIO-Requimte
- Departamento de Química
- Faculdade de Ciências e Tecnologia
- Universidade NOVA de Lisboa
- 2829-516 Caparica
| |
Collapse
|
13
|
Huang L, Li X, Ren Y, Wang X. A monolithic three-dimensional macroporous graphene anode with low cost for high performance microbial fuel cells. RSC Adv 2016. [DOI: 10.1039/c5ra24718g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Monolithic 3D-G which is inflexible and has a macroporous structure, crumpled matrix, good conductivity and low cost enhanced the electrogenesis of a MFC.
Collapse
Affiliation(s)
- Lihua Huang
- Laboratory of Environmental Biotechnology
- School of Environmental and Civil Engineering
- Jiangnan University
- Wuxi 214122
- PR China
| | - Xiufen Li
- Laboratory of Environmental Biotechnology
- School of Environmental and Civil Engineering
- Jiangnan University
- Wuxi 214122
- PR China
| | - Yueping Ren
- Laboratory of Environmental Biotechnology
- School of Environmental and Civil Engineering
- Jiangnan University
- Wuxi 214122
- PR China
| | - Xinhua Wang
- Laboratory of Environmental Biotechnology
- School of Environmental and Civil Engineering
- Jiangnan University
- Wuxi 214122
- PR China
| |
Collapse
|
14
|
Dantas JM, Kokhan O, Pokkuluri PR, Salgueiro CA. Molecular interaction studies revealed the bifunctional behavior of triheme cytochrome PpcA from Geobacter sulfurreducens toward the redox active analog of humic substances. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1129-38. [DOI: 10.1016/j.bbabio.2015.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 05/15/2015] [Accepted: 06/07/2015] [Indexed: 11/17/2022]
|
15
|
Dantas JM, Morgado L, Aklujkar M, Bruix M, Londer YY, Schiffer M, Pokkuluri PR, Salgueiro CA. Rational engineering of Geobacter sulfurreducens electron transfer components: a foundation for building improved Geobacter-based bioelectrochemical technologies. Front Microbiol 2015; 6:752. [PMID: 26284042 PMCID: PMC4519760 DOI: 10.3389/fmicb.2015.00752] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/08/2015] [Indexed: 11/22/2022] Open
Abstract
Multiheme cytochromes have been implicated in Geobacter sulfurreducens extracellular electron transfer (EET). These proteins are potential targets to improve EET and enhance bioremediation and electrical current production by G. sulfurreducens. However, the functional characterization of multiheme cytochromes is particularly complex due to the co-existence of several microstates in solution, connecting the fully reduced and fully oxidized states. Over the last decade, new strategies have been developed to characterize multiheme redox proteins functionally and structurally. These strategies were used to reveal the functional mechanism of G. sulfurreducens multiheme cytochromes and also to identify key residues in these proteins for EET. In previous studies, we set the foundations for enhancement of the EET abilities of G. sulfurreducens by characterizing a family of five triheme cytochromes (PpcA-E). These periplasmic cytochromes are implicated in electron transfer between the oxidative reactions of metabolism in the cytoplasm and the reduction of extracellular terminal electron acceptors at the cell's outer surface. The results obtained suggested that PpcA can couple e−/H+ transfer, a property that might contribute to the proton electrochemical gradient across the cytoplasmic membrane for metabolic energy production. The structural and functional properties of PpcA were characterized in detail and used for rational design of a family of 23 single site PpcA mutants. In this review, we summarize the functional characterization of the native and mutant proteins. Mutants that retain the mechanistic features of PpcA and adopt preferential e−/H+ transfer pathways at lower reduction potential values compared to the wild-type protein were selected for in vivo studies as the best candidates to increase the electron transfer rate of G. sulfurreducens. For the first time G. sulfurreducens strains have been manipulated by the introduction of mutant forms of essential proteins with the aim to develop and improve bioelectrochemical technologies.
Collapse
Affiliation(s)
- Joana M Dantas
- Research Unit on Applied Molecular Biosciences (UCIBIO), Rede de Química e Tecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa Caparica, Portugal
| | - Leonor Morgado
- Research Unit on Applied Molecular Biosciences (UCIBIO), Rede de Química e Tecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa Caparica, Portugal
| | - Muktak Aklujkar
- Department of Biological Sciences, Towson University Towson, MD, USA
| | - Marta Bruix
- Departamento de Química Física Biológica, Instituto de Química-Física "Rocasolano", Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Yuri Y Londer
- Biosciences Division, Argonne National Laboratory Lemont, IL, USA
| | | | - P Raj Pokkuluri
- Biosciences Division, Argonne National Laboratory Lemont, IL, USA
| | - Carlos A Salgueiro
- Research Unit on Applied Molecular Biosciences (UCIBIO), Rede de Química e Tecnologia, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa Caparica, Portugal
| |
Collapse
|
16
|
Kokhan O, Ponomarenko NS, Pokkuluri PR, Schiffer M, Mulfort KL, Tiede DM. Bidirectional Photoinduced Electron Transfer in Ruthenium(II)-Tris-bipyridyl-Modified PpcA, a Multi-heme c-Type Cytochrome from Geobacter sulfurreducens. J Phys Chem B 2015; 119:7612-24. [PMID: 25731703 DOI: 10.1021/jp511558f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PpcA, a tri-heme cytochrome c7 from Geobacter sulfurreducens, was investigated as a model for photosensitizer-initiated electron transfer within a multi-heme "molecular wire" protein architecture. Escherichia coli expression of PpcA was found to be tolerant of cysteine site-directed mutagenesis, demonstrated by the successful expression of natively folded proteins bearing cysteine mutations at a series of sites selected to vary characteristically with respect to the three -CXXCH- heme binding domains. The introduced cysteines readily reacted with Ru(II)-(2,2'-bpy)2(4-bromomethyl-4'-methyl-2,2'-bipyridine) to form covalently linked constructs that support both photo-oxidative and photo-reductive quenching of the photosensitizer excited state, depending upon the initial heme redox state. Excited-state electron-transfer times were found to vary from 6 × 10(-12) to 4 × 10(-8) s, correlated with the distance and pathways for electron transfer. The fastest rate is more than 10(3)-fold faster than previously reported for photosensitizer-redox protein constructs using amino acid residue linking. Clear evidence for inter-heme electron transfer within the multi-heme protein is not detected within the lifetimes of the charge-separated states. These results demonstrate an opportunity to develop multi-heme c-cytochromes for investigation of electron transfer in protein "molecular wires" and to serve as frameworks for metalloprotein designs that support multiple-electron-transfer redox chemistry.
Collapse
Affiliation(s)
- Oleksandr Kokhan
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Nina S Ponomarenko
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - P Raj Pokkuluri
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Marianne Schiffer
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Karen L Mulfort
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - David M Tiede
- †Chemical Sciences and Engineering Division and ‡Biosciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| |
Collapse
|
17
|
Dantas JM, Morgado L, Marques AC, Salgueiro CA. Probing the effect of ionic strength on the functional robustness of the triheme cytochrome PpcA from Geobacter sulfurreducens: a contribution for optimizing biofuel cell's power density. J Phys Chem B 2014; 118:12416-25. [PMID: 25275217 DOI: 10.1021/jp507898x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The increase of conductivity of electrolytes favors the current production in microbial fuel cells (MFCs). Adaptation of cell cultures to higher ionic strength is a promising strategy to increase electricity production. The bacterium Geobacter sulfurreducens is considered a leading candidate for MFCs. Therefore, it is important to evaluate the impact of the ionic strength on the functional properties of key periplasmic proteins that warrants electron transfer to cell exterior. The effect of the ionic strength on the functional properties of triheme cytochrome PpcA, the most abundant periplasmic cytochrome in G. sulfurreducens, was investigated by NMR and potentiometric methods. The redox properties of heme IV are the most affected ones. Chemical shift perturbation measurements on the backbone NMR signals, at increasing ionic strength, also showed that the region close to heme IV is the most affected due to the large number of positively charged residues, which confer a highly positive electrostatic surface around this heme. The shielding of these positive charges at high ionic strength explain the observed decrease in the reduction potential of heme IV and shows that PpcA was designed to maintain its functional mechanistic features even at high ionic strength.
Collapse
Affiliation(s)
- Joana M Dantas
- Requimte-CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , Campus Caparica, 2829-516 Caparica, Portugal
| | | | | | | |
Collapse
|
18
|
Kokhan O, Ponomarenko N, Pokkuluri PR, Schiffer M, Tiede DM. Multimerization of solution-state proteins by tetrakis(4-sulfonatophenyl)porphyrin. Biochemistry 2014; 53:5070-9. [PMID: 25028772 DOI: 10.1021/bi500278g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Surface binding and interactions of anionic porphyins bound to cationic proteins have been studied for nearly three decades and are relevant as models for protein surface molecular recognition and photoinitiated electron transfer. However, interpretation of data in nearly all reports explicitly or implicitly assumed interaction of porphyrin with monodisperse proteins in solutions. In this report, using small-angle X-ray scattering with solution phase samples, we demonstrate that horse heart cytochrome (cyt) c, triheme cytochrome c7 PpcA from Geobacter sulfurreducens, and hen egg lysozyme multimerize in the presence of zinc tetrakis(4-sulfonatophenyl)porphyrin (ZnTPPS). Multimerization of cyt c showed a pH dependence with a stronger apparent binding affinity under alkaline conditions and was weakened in the presence of a high salt concentration. Ferric-cyt c formed complexes larger than those formed by ferro-cyt c. Free base TPPS and FeTPPS facilitated formation of complexes larger than those of ZnTPPS. No increase in protein aggregation state for cationic proteins was observed in the presence of cationic porphyrins. All-atom molecular dynamics simulations of cyt c and PpcA with free base TPPS corroborated X-ray scattering results and revealed a mechanism by which the tetrasubstituted charged porphyrins serve as bridging ligands nucleating multimerization of the complementarily charged protein. The final aggregation products suggest that multimerization involves a combination of electrostatic and hydrophobic interactions. The results demonstrate an overlooked complexity in the design of multifunctional ligands for protein surface recognition.
Collapse
Affiliation(s)
- Oleksandr Kokhan
- Chemical Sciences and Engineering Division, Argonne National Laboratory , Lemont, Illinois 60439, United States
| | | | | | | | | |
Collapse
|
19
|
Paquete CM, Fonseca BM, Cruz DR, Pereira TM, Pacheco I, Soares CM, Louro RO. Exploring the molecular mechanisms of electron shuttling across the microbe/metal space. Front Microbiol 2014; 5:318. [PMID: 25018753 PMCID: PMC4073285 DOI: 10.3389/fmicb.2014.00318] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 06/10/2014] [Indexed: 11/27/2022] Open
Abstract
Dissimilatory metal reducing organisms play key roles in the biogeochemical cycle of metals as well as in the durability of submerged and buried metallic structures. The molecular mechanisms that support electron transfer across the microbe-metal interface in these organisms remain poorly explored. It is known that outer membrane proteins, in particular multiheme cytochromes, are essential for this type of metabolism, being responsible for direct and indirect, via electron shuttles, interaction with the insoluble electron acceptors. Soluble electron shuttles such as flavins, phenazines, and humic acids are known to enhance extracellular electron transfer. In this work, this phenomenon was explored. All known outer membrane decaheme cytochromes from Shewanella oneidensis MR-1 with known metal terminal reductase activity and a undecaheme cytochrome from Shewanella sp. HRCR-6 were expressed and purified. Their interactions with soluble electron shuttles were studied using stopped-flow kinetics, NMR spectroscopy, and molecular simulations. The results show that despite the structural similarities, expected from the available structural data and sequence homology, the detailed characteristics of their interactions with soluble electron shuttles are different. MtrC and OmcA appear to interact with a variety of different electron shuttles in the close vicinity of some of their hemes, and with affinities that are biologically relevant for the concentrations typical found in the medium for this type of compounds. All data support a view of a distant interaction between the hemes of MtrF and the electron shuttles. For UndA a clear structural characterization was achieved for the interaction with AQDS a humic acid analog. These results provide guidance for future work of the manipulation of these proteins toward modulation of their role in metal attachment and reduction.
Collapse
Affiliation(s)
- Catarina M Paquete
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Bruno M Fonseca
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Davide R Cruz
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Tiago M Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Isabel Pacheco
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Cláudio M Soares
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| | - Ricardo O Louro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras, Portugal
| |
Collapse
|