Diving into the redox properties of Geobacter sulfurreducens cytochromes: A model for extracellular electron transfer

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Abstract

Geobacter bacteria have a remarkable respiratory versatility that includes the dissimilatory reduction of insoluble metal oxides in natural habitats and electron transfer to electrode surfaces from which electricity can be harvested. In both cases, electrons need to be exported from the cell interior to the exterior via a mechanism designated as extracellular electron transfer (EET). Several c-type cytochromes from G. sulfurreducens (Gs) were identified as key players in this process. Biochemical and biophysical data have been obtained for ten Gs cytochromes, including inner-membrane associated (MacA), periplasmic (PpcA, PpcB, PpcC, PpcD, PpcE and GSU1996) and outer membrane-associated (OmcF, OmcS and OmcZ). The redox properties of these cytochromes have been determined, except for PpcC and GSU1996. In this perspective, the reduction potentials of these two cytochromes were determined by potentiometric redox titrations followed by visible spectroscopy. The data obtained are taken together with those available for other key cytochromes to present a thorough overview of the current knowledge of Gs EET mechanisms and provide a possible rationalization for the existence of several multiheme cytochromes involved in the same respiratory pathways.

Original languageEnglish
Pages (from-to)9335-9344
Number of pages10
JournalDalton Transactions
Volume44
Issue number20
DOIs
Publication statusPublished - 28 May 2015

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Geobacter
Diving
Cytochromes
Oxidation-Reduction
Electrons
Cytochrome c Group
Membranes
Electricity
Titration
Oxides
Ecosystem
Spectrum Analysis
Bacteria
Electrodes
Metals
Spectroscopy

Keywords

  • C-TYPE CYTOCHROME
  • SHEWANELLA-ONEIDENSIS MR-1
  • PUTREFACIENS MR-1
  • THERMODYNAMIC CHARACTERIZATION
  • METAL REDUCTION
  • PROTEIN COMPLEX
  • OUTER-SURFACE
  • FUEL-CELLS
  • FE(III)
  • BIOFILMS

Cite this

@article{94a5fbd9059d409995e79f087ab4eca6,
title = "Diving into the redox properties of Geobacter sulfurreducens cytochromes: A model for extracellular electron transfer",
abstract = "Geobacter bacteria have a remarkable respiratory versatility that includes the dissimilatory reduction of insoluble metal oxides in natural habitats and electron transfer to electrode surfaces from which electricity can be harvested. In both cases, electrons need to be exported from the cell interior to the exterior via a mechanism designated as extracellular electron transfer (EET). Several c-type cytochromes from G. sulfurreducens (Gs) were identified as key players in this process. Biochemical and biophysical data have been obtained for ten Gs cytochromes, including inner-membrane associated (MacA), periplasmic (PpcA, PpcB, PpcC, PpcD, PpcE and GSU1996) and outer membrane-associated (OmcF, OmcS and OmcZ). The redox properties of these cytochromes have been determined, except for PpcC and GSU1996. In this perspective, the reduction potentials of these two cytochromes were determined by potentiometric redox titrations followed by visible spectroscopy. The data obtained are taken together with those available for other key cytochromes to present a thorough overview of the current knowledge of Gs EET mechanisms and provide a possible rationalization for the existence of several multiheme cytochromes involved in the same respiratory pathways.",
keywords = "C-TYPE CYTOCHROME, SHEWANELLA-ONEIDENSIS MR-1, PUTREFACIENS MR-1, THERMODYNAMIC CHARACTERIZATION, METAL REDUCTION, PROTEIN COMPLEX, OUTER-SURFACE, FUEL-CELLS, FE(III), BIOFILMS",
author = "Santos, {Telma C.} and Silva, {Marta A.} and Leonor Morgado and Dantas, {Joana M.} and Salgueiro, {Carlos A.}",
note = "This work was supported by project grant PTDC/BBB-BEP/0753/2012 (to CAS), UID/Multi/04378/2013 (to UCIBIO - REQUIMTE) and the re-equipment grant REEQ/336/BIO/2005 from Fundacao para a Ciencia e a Tecnologia (FCT), Portugal. JMD and TCS are recipient of grants SFRH/BD/89701/2012 and PD/BD/106037/2015 from FCT, respectively.",
year = "2015",
month = "5",
day = "28",
doi = "10.1039/c5dt00556f",
language = "English",
volume = "44",
pages = "9335--9344",
journal = "Dalton Transactions",
issn = "1477-9226",
publisher = "Royal Society of Chemistry",
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TY - JOUR

T1 - Diving into the redox properties of Geobacter sulfurreducens cytochromes: A model for extracellular electron transfer

AU - Santos, Telma C.

AU - Silva, Marta A.

AU - Morgado, Leonor

AU - Dantas, Joana M.

AU - Salgueiro, Carlos A.

N1 - This work was supported by project grant PTDC/BBB-BEP/0753/2012 (to CAS), UID/Multi/04378/2013 (to UCIBIO - REQUIMTE) and the re-equipment grant REEQ/336/BIO/2005 from Fundacao para a Ciencia e a Tecnologia (FCT), Portugal. JMD and TCS are recipient of grants SFRH/BD/89701/2012 and PD/BD/106037/2015 from FCT, respectively.

PY - 2015/5/28

Y1 - 2015/5/28

N2 - Geobacter bacteria have a remarkable respiratory versatility that includes the dissimilatory reduction of insoluble metal oxides in natural habitats and electron transfer to electrode surfaces from which electricity can be harvested. In both cases, electrons need to be exported from the cell interior to the exterior via a mechanism designated as extracellular electron transfer (EET). Several c-type cytochromes from G. sulfurreducens (Gs) were identified as key players in this process. Biochemical and biophysical data have been obtained for ten Gs cytochromes, including inner-membrane associated (MacA), periplasmic (PpcA, PpcB, PpcC, PpcD, PpcE and GSU1996) and outer membrane-associated (OmcF, OmcS and OmcZ). The redox properties of these cytochromes have been determined, except for PpcC and GSU1996. In this perspective, the reduction potentials of these two cytochromes were determined by potentiometric redox titrations followed by visible spectroscopy. The data obtained are taken together with those available for other key cytochromes to present a thorough overview of the current knowledge of Gs EET mechanisms and provide a possible rationalization for the existence of several multiheme cytochromes involved in the same respiratory pathways.

AB - Geobacter bacteria have a remarkable respiratory versatility that includes the dissimilatory reduction of insoluble metal oxides in natural habitats and electron transfer to electrode surfaces from which electricity can be harvested. In both cases, electrons need to be exported from the cell interior to the exterior via a mechanism designated as extracellular electron transfer (EET). Several c-type cytochromes from G. sulfurreducens (Gs) were identified as key players in this process. Biochemical and biophysical data have been obtained for ten Gs cytochromes, including inner-membrane associated (MacA), periplasmic (PpcA, PpcB, PpcC, PpcD, PpcE and GSU1996) and outer membrane-associated (OmcF, OmcS and OmcZ). The redox properties of these cytochromes have been determined, except for PpcC and GSU1996. In this perspective, the reduction potentials of these two cytochromes were determined by potentiometric redox titrations followed by visible spectroscopy. The data obtained are taken together with those available for other key cytochromes to present a thorough overview of the current knowledge of Gs EET mechanisms and provide a possible rationalization for the existence of several multiheme cytochromes involved in the same respiratory pathways.

KW - C-TYPE CYTOCHROME

KW - SHEWANELLA-ONEIDENSIS MR-1

KW - PUTREFACIENS MR-1

KW - THERMODYNAMIC CHARACTERIZATION

KW - METAL REDUCTION

KW - PROTEIN COMPLEX

KW - OUTER-SURFACE

KW - FUEL-CELLS

KW - FE(III)

KW - BIOFILMS

UR - http://www.scopus.com/inward/record.url?scp=84930682534&partnerID=8YFLogxK

U2 - 10.1039/c5dt00556f

DO - 10.1039/c5dt00556f

M3 - Review article

VL - 44

SP - 9335

EP - 9344

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 20

ER -