1
|
Mostajabi Sarhangi S, Matyushov DV. Electron Tunneling in Biology: When Does it Matter? ACS OMEGA 2023; 8:27355-27365. [PMID: 37546584 PMCID: PMC10399179 DOI: 10.1021/acsomega.3c02719] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023]
Abstract
Electrons can tunnel between cofactor molecules positioned along biological electron transport chains up to a distance of ≃ 20 Å on the millisecond time scale of enzymatic turnover. This tunneling range determines the design of biological energy chains facilitating the cross-membrane transport of electrons. Tunneling distance and cofactors' redox potentials become the main physical parameters affecting the rate of electron transport. In addition, universal charge-transport properties are assigned to all proteins, making protein identity, flexibility, and dynamics insignificant. This paradigm is challenged by dynamical models of electron transfer, showing that the electron hopping rate is constant within the crossover distance R* ≃ 12 Å, followed with an exponential falloff at longer distances. If this hypothesis is fully confirmed, natural and man-made energy chains for electron transport should be best designed by placing redox cofactors near the crossover distance R*. Protein flexibility and dynamics affect the magnitude of the maximum hopping rate within the crossover distance. Changes in protein flexibility between forward and backward transitions contribute to vectorial charge transport. For biological energy chains, charge transport through proteins is not defined by universal parameters, and protein identity matters.
Collapse
Affiliation(s)
- Setare Mostajabi Sarhangi
- School of Molecular Sciences and Department
of Physics, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, United
States
| | - Dmitry V. Matyushov
- School of Molecular Sciences and Department
of Physics, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, United
States
| |
Collapse
|
2
|
Mostajabi Sarhangi S, Matyushov DV. Effect of Water Deuteration on Protein Electron Transfer. J Phys Chem Lett 2023; 14:723-729. [PMID: 36648391 DOI: 10.1021/acs.jpclett.2c03690] [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: 06/17/2023]
Abstract
Traditional theories of long-range protein electron transfer describe the reaction rate in terms of the tunneling distance and the reaction free energy. They do not recognize two physical effects: (i) local wetting of the active site by hydration water and (ii) protein identity affecting the rate through dynamics and flexibility. We find, by molecular dynamics simulations, a significant, ∼25 times, slowing down of the rate of protein electron transfer upon deuteration. H/D substitution changes the rate constant pre-exponential factor in the regime of electron transfer controlled by medium dynamics. Switching from light to heavy water increases the effective medium relaxation time. The effect is caused by both a global change in the flexibility of the protein backbone and locally stronger hydrogen bonds to charged residues.
Collapse
Affiliation(s)
- Setare Mostajabi Sarhangi
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
| | - Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona85287-1504, United States
| |
Collapse
|
3
|
Dahl PJ, Yi SM, Gu Y, Acharya A, Shipps C, Neu J, O’Brien JP, Morzan UN, Chaudhuri S, Guberman-Pfeffer MJ, Vu D, Yalcin SE, Batista VS, Malvankar NS. A 300-fold conductivity increase in microbial cytochrome nanowires due to temperature-induced restructuring of hydrogen bonding networks. SCIENCE ADVANCES 2022; 8:eabm7193. [PMID: 35544567 PMCID: PMC9094664 DOI: 10.1126/sciadv.abm7193] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/28/2022] [Indexed: 06/10/2023]
Abstract
Although proteins are considered as nonconductors that transfer electrons only up to 1 to 2 nanometers via tunneling, Geobacter sulfurreducens transports respiratory electrons over micrometers, to insoluble acceptors or syntrophic partner cells, via nanowires composed of polymerized cytochrome OmcS. However, the mechanism enabling this long-range conduction is unclear. Here, we demonstrate that individual nanowires exhibit theoretically predicted hopping conductance, at rate (>1010 s-1) comparable to synthetic molecular wires, with negligible carrier loss over micrometers. Unexpectedly, nanowires show a 300-fold increase in their intrinsic conductance upon cooling, which vanishes upon deuteration. Computations show that cooling causes a massive rearrangement of hydrogen bonding networks in nanowires. Cooling makes hemes more planar, as revealed by Raman spectroscopy and simulations, and lowers their reduction potential. We find that the protein surrounding the hemes acts as a temperature-sensitive switch that controls charge transport by sensing environmental perturbations. Rational engineering of heme environments could enable systematic tuning of extracellular respiration.
Collapse
Affiliation(s)
- Peter J. Dahl
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Sophia M. Yi
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Yangqi Gu
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Atanu Acharya
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Catharine Shipps
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Jens Neu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - J. Patrick O’Brien
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Uriel N. Morzan
- Department of Chemistry, Yale University, New Haven, CT, USA
| | | | - Matthew J. Guberman-Pfeffer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Dennis Vu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | - Sibel Ebru Yalcin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| | | | - Nikhil S. Malvankar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, New Haven, CT, USA
| |
Collapse
|
4
|
Ashkarran AA, Hosseini A, Loloee R, Perry G, Lee KB, Lund M, Ejtehadi MR, Mahmoudi M. Conformation- and phosphorylation-dependent electron tunnelling across self-assembled monolayers of tau peptides. J Colloid Interface Sci 2022; 606:2038-2050. [PMID: 34749450 DOI: 10.1016/j.jcis.2021.09.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 09/17/2021] [Accepted: 09/28/2021] [Indexed: 10/20/2022]
Abstract
We report on charge transport across self-assembled monolayers (SAMs) of short tau peptides by probing the electron tunneling rates and quantum mechanical simulation. We measured the electron tunneling rates across SAMs of carboxyl-terminated linker molecules (C6H12O2S) and short cis-tau (CT) and trans-tau (TT) peptides, supported on template-stripped gold (AuTS) bottom electrode, with Eutectic Gallium-Indium (EGaIn)(EGaIn) top electrode. Measurements of the current density across thousands of AuTS/linker/tau//Ga2O3/EGaIn single-molecule junctions show that the tunneling current across CT peptide is one order of magnitude lower than that of TT peptide. Quantum mechanical simulation demonstrated a wider energy bandgap of the CT peptide, as compared to the TT peptide, which causes a reduction in its electron tunneling current. Our findings also revealed the critical role of phosphorylation in altering the charge transport characteristics of short peptides; more specifically, we found that the presence of phosphate groups can reduce the energy band gap in tau peptides and alter their electrical properties. Our results suggest that conformational and phosphorylation of short peptides (e.g., tau) can significantly change their charge transport characteristics and energy levels.
Collapse
Affiliation(s)
- Ali Akbar Ashkarran
- Precision Health Program and Department of Radiology, Michigan State University, East Lansing, MI 48824, USA.
| | - Atiyeh Hosseini
- Division of Theoretical Chemistry, Lund University, Lund, Sweden; Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran
| | - Reza Loloee
- Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA
| | - George Perry
- Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Ki-Bum Lee
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Mikael Lund
- Division of Theoretical Chemistry, Lund University, Lund, Sweden.
| | | | - Morteza Mahmoudi
- Precision Health Program and Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
5
|
Engelbrekt C, Nazmutdinov RR, Shermukhamedov S, Ulstrup J, Zinkicheva TT, Xiao X. Complex single‐molecule and molecular scale entities in electrochemical environments: Mechanisms and challenges. ELECTROCHEMICAL SCIENCE ADVANCES 2021. [DOI: 10.1002/elsa.202100157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Christian Engelbrekt
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
| | - Renat R. Nazmutdinov
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Shokirbek Shermukhamedov
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Jens Ulstrup
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
| | - Tamara T. Zinkicheva
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Xinxin Xiao
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
| |
Collapse
|
6
|
Nguyen QV, Frisbie CD. Hopping Conductance in Molecular Wires Exhibits a Large Heavy-Atom Kinetic Isotope Effect. J Am Chem Soc 2021; 143:2638-2643. [PMID: 33587628 DOI: 10.1021/jacs.0c12244] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We report a large kinetic isotope effect (KIE) for intramolecular charge transport in π-conjugated oligophenyleneimine (OPI) molecules connected to Au electrodes. 13C and 15N substitution on the imine bonds produces a conductance KIE of ∼2.7 per labeled atom in long OPI wires >4 nm in length, far larger than typical heavy-atom KIEs for chemical reactions. In contrast, isotopic labeling in shorter OPI wires <4 nm does not produce a conductance KIE, consistent with a direct tunneling mechanism. Temperature-dependent measurements reveal that conductance for a long 15N-substituted OPI wire is activated, and we propose that the exceptionally large conductance KIEs imply a thermally assisted, through-barrier polaron tunneling mechanism. In general, observation of large conductance KIEs opens up considerable opportunities for understanding microscopic conduction mechanisms in π-conjugated molecules.
Collapse
Affiliation(s)
- Quyen Van Nguyen
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
7
|
Chen X, Salim T, Zhang Z, Yu X, Volkova I, Nijhuis CA. Large Increase in the Dielectric Constant and Partial Loss of Coherence Increases Tunneling Rates across Molecular Wires. ACS APPLIED MATERIALS & INTERFACES 2020; 12:45111-45121. [PMID: 32897683 DOI: 10.1021/acsami.0c11106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although the dielectric behavior of monolayers is important in a large range of applications, its role in charge transport studies involving molecular junctions is largely ignored. This paper describes a large increase in the relative static dielectric constant (εr) by simply increasing the thickness of well-organized monolayers of oligoglycine and oligo(ethylene glycol) from 7 up to 14. The resulting large capacitance of 3.5-5.1 μF/cm2 is thickness-independent, which is highly attractive for field-effect transistor applications. This increase of εr results in a linear increase of the thermal activation energy by a factor of 6, which suggests that the mechanism of charge transport gradually changes from coherent to (partially) incoherent tunneling. The comparisons of oligoglycine (which readily forms hydrogen bonds with neighboring molecules) and methyl terminated oligo(ethylene glycol) (which lacks hydrogen bond donors) monolayers, kinetic isotope effects, and relative humidity-dependent measurements all indicate the importance of strong hydrogen bonds involving ionic species and strongly bonded water in the unusual dielectric behavior and the incoherent tunneling mechanism. This partial loss of coherence of the charge carriers can explain the unusually small tunneling decay coefficients across long molecular wires, and the length-dependent increase of εr of monolayers opens up interesting new applications.
Collapse
Affiliation(s)
- Xiaoping Chen
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Teddy Salim
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Ziyu Zhang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603, Singapore
| | - Ira Volkova
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| |
Collapse
|
8
|
Cao L, Yuan L, Yang M, Nerngchamnong N, Thompson D, Yu X, Qi DC, Nijhuis CA. The supramolecular structure and van der Waals interactions affect the electronic structure of ferrocenyl-alkanethiolate SAMs on gold and silver electrodes. NANOSCALE ADVANCES 2019; 1:1991-2002. [PMID: 36134247 PMCID: PMC9417838 DOI: 10.1039/c9na00107g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 03/20/2019] [Indexed: 06/12/2023]
Abstract
Understanding the influence of structural properties on the electronic structure will pave the way for optimization of charge transport properties of SAM devices. In this study, we systematically investigate the supramolecular and electronic structures of ferrocene (Fc) terminated alkanethiolate (SC n Fc) SAMs on both Au and Ag substrates with n = 1-15 by using a combination of synchrotron based near edge X-ray absorption spectroscopy (NEXAFS), photoemission spectroscopy (PES), and density functional theory (DFT) calculations. Odd-even effects in the supramolecular structure persist over the entire range of n = 1-15, which, in turn, explain the odd-even effects in the onset energy of the highest occupied molecular (HOMO) orbital. The orientation of the Fc moieties and the strength of Fc-substrate coupling, which both depend on n, affects the work function (WF). The variation of WF shows an odd-even effect in the weak electrode-Fc coupling regime for n ≥ 8, whereas the odd-even effect diminishes for n < 8 due to hybridization between Fc and the electrode (n < 3) or van der Waals (vdW) interactions between Fc and the electrode (n = 3-7). These results confirm that subtle changes in the supramolecular structure of the SAMs cause significant electronic changes that have a large influence on device properties.
Collapse
Affiliation(s)
- Liang Cao
- Department of Chemistry, National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Sciences 350 Shushanhu Road Hefei 230031 China
- Department of Physics, National University of Singapore 2 Science Drive 3 Singapore 117542 Singapore
| | - Li Yuan
- Department of Chemistry, National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Ming Yang
- Institute of Materials Research and Engineering (IMRE), Innovis 2 Fusionopolis Way Singapore 138634 Singapore
| | - Nisachol Nerngchamnong
- Department of Chemistry, National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick V94 T9PX Ireland
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source, National University of Singapore 5 Research Link Singapore 117603 Singapore
| | - Dong-Chen Qi
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology Brisbane Queensland 4001 Australia
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University Melbourne Victoria 3086 Australia
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore 6 Science Drive 2 Singapore 117546 Singapore
- NUSNNI-Nanocore, National University of Singapore Singapore 117411 Singapore
| |
Collapse
|
9
|
Song X, Zhang F, Bu Y. Dynamic relaying properties of a β-turn peptide in long-range electron transfer. J Comput Chem 2019; 40:988-996. [PMID: 30451309 DOI: 10.1002/jcc.25541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/30/2018] [Accepted: 07/03/2018] [Indexed: 11/05/2022]
Abstract
The relay stations play a significant role in long-range charge hopping transfer in proteins. Although studies have clarified that many more protein structural motifs can function as relays in charge hopping transfers by acting as intermediate charge carriers, the relaying properties are still poorly understood. In this work, taking a β-turn oligopeptide as an example, we report a dynamic character of a relay with tunable relaying properties using the density functional theory calculations. Our main finding is that a β-turn peptide can serve as an effective electron relay in facilitating long-range electron migration and its relay properties is vibration-tunable. The vibration-induced structural transient distortions remarkably affect the lowest occupied molecular orbital (LUMO) energy, vertical electron affinity and electron-binding mode of the β-turn oligopeptide and the singly occupied molecular orbital (SOMO) energy of the corresponding electron adduct and thus the relaying properties. Different vibration modes lead to different structural distortions and thus have different effects on the relaying properties and ability of the β-turn peptide. For the relaying properties, there approximately is a linear negative correlation of electron affinity with the LUMO energy of the β-turn or the SOMO energy of its electron adduct. Besides, such relaying properties also vary in the vibration evolution process, and the electron-binding modes may be tunable. As an important addition to the known static charge relaying properties occurring in various protein structural motifs, this work reports the dynamic electron-relaying characteristics of a β-turn oligopeptide with variable relaying properties governed by molecular vibrations which can be applied to different proteins in mediating long-range charge transfers. Clearly, this work reveals molecular vibration effects on the electron relaying properties of protein structural motifs and provides new insights into the dynamics of long-range charge transfers in proteins. © 2018 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Xiufang Song
- School of Chemistry &Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan 250100, People's Republic of China
| | - Fengying Zhang
- School of Chemistry &Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan 250100, People's Republic of China
| | - Yuxiang Bu
- School of Chemistry &Chemical Engineering, Institute of Theoretical Chemistry, Shandong University, Jinan 250100, People's Republic of China
| |
Collapse
|
10
|
Kumar KS, Pasula RR, Lim S, Nijhuis CA. Long-Range Tunneling Processes across Ferritin-Based Junctions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:1824-30. [PMID: 26708136 DOI: 10.1002/adma.201504402] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/13/2015] [Indexed: 05/23/2023]
Abstract
The mechanism of long-range charge transport across tunneling junctions with monolayers of ferritin is investigated. It is shown that the mechanism can be switched between coherent tunneling, sequential tunneling, and hopping by changing the iron content inside the ferritin. This study shows that ferritins are an interesting class of biomolecules to control charge transport.
Collapse
Affiliation(s)
| | - Rupali Reddy Pasula
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore
| | - Sierin Lim
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore
- NTU-Northwestern Institute for Nanomedicine, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| |
Collapse
|
11
|
Rajabi K, Ashcroft AE, Radford SE. Mass spectrometric methods to analyze the structural organization of macromolecular complexes. Methods 2015; 89:13-21. [DOI: 10.1016/j.ymeth.2015.03.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/25/2015] [Accepted: 03/06/2015] [Indexed: 01/14/2023] Open
|
12
|
Raichlin S, Pecht I, Sheves M, Cahen D. Protein Electronic Conductors: Hemin-Substrate Bonding Dictates Transport Mechanism and Efficiency across Myoglobin. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
13
|
Raichlin S, Pecht I, Sheves M, Cahen D. Protein Electronic Conductors: Hemin-Substrate Bonding Dictates Transport Mechanism and Efficiency across Myoglobin. Angew Chem Int Ed Engl 2015; 54:12379-83. [DOI: 10.1002/anie.201505951] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Indexed: 11/09/2022]
|
14
|
Castañeda Ocampo OE, Gordiichuk P, Catarci S, Gautier DA, Herrmann A, Chiechi RC. Mechanism of Orientation-Dependent Asymmetric Charge Transport in Tunneling Junctions Comprising Photosystem I. J Am Chem Soc 2015; 137:8419-27. [PMID: 26057523 PMCID: PMC4558993 DOI: 10.1021/jacs.5b01241] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently, photoactive proteins have gained a lot of attention due to their incorporation into bioinspired (photo)electrochemical and solar cells. This paper describes the measurement of the asymmetry of current transport of self-assembled monolayers (SAMs) of the entire photosystem I (PSI) protein complex (not the isolated reaction center, RCI), on two different "director SAMs" supported by ultraflat Au substrates. The director SAMs induce the preferential orientation of PSI, which manifest as asymmetry in tunneling charge-transport. We measured the oriented SAMs of PSI using eutectic Ga-In (EGaIn), a large-area technique, and conducting probe atomic force microscopy (CP-AFM), a single-complex technique, and determined that the transport properties are comparable. By varying the temperatures at which the measurements were performed, we found that there is no measurable dependence of the current on temperature from ±0.1 to ±1.0 V bias, and thus, we suggest tunneling as the mechanism for transport; there are no thermally activated (e.g., hopping) processes. Therefore, it is likely that relaxation in the electron transport chain is not responsible for the asymmetry in the conductance of SAMs of PSI complexes in these junctions, which we ascribe instead to the presence of a large, net dipole moment present in PSI.
Collapse
Affiliation(s)
- Olga E Castañeda Ocampo
- †Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Pavlo Gordiichuk
- ‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Stefano Catarci
- ‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Daniel A Gautier
- ‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Andreas Herrmann
- ‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ryan C Chiechi
- †Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,‡Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| |
Collapse
|
15
|
Amdursky N, Sepunaru L, Raichlin S, Pecht I, Sheves M, Cahen D. Electron Transfer Proteins as Electronic Conductors: Significance of the Metal and Its Binding Site in the Blue Cu Protein, Azurin. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2015; 2:1400026. [PMID: 27980928 PMCID: PMC5115354 DOI: 10.1002/advs.201400026] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/08/2015] [Indexed: 05/07/2023]
Abstract
Electron transfer (ET) proteins are biomolecules with specific functions, selected by evolution. As such they are attractive candidates for use in potential bioelectronic devices. The blue copper protein azurin (Az) is one of the most-studied ET proteins. Traditional spectroscopic, electrochemical, and kinetic methods employed for studying ET to/from the protein's Cu ion have been complemented more recently by studies of electrical conduction through a monolayer of Az in the solid-state, sandwiched between electrodes. As the latter type of measurement does not require involvement of a redox process, it also allows monitoring electronic transport (ETp) via redox-inactive Az-derivatives. Here, results of macroscopic ETp via redox-active and -inactive Az derivatives, i.e., Cu(II) and Cu(I)-Az, apo-Az, Co(II)-Az, Ni(II)-Az, and Zn(II)-Az are reported and compared. It is found that earlier reported temperature independence of ETp via Cu(II)-Az (from 20 K until denaturation) is unique, as ETp via all other derivatives is thermally activated at temperatures >≈200 K. Conduction via Cu(I)-Az shows unexpected temperature dependence >≈200 K, with currents decreasing at positive and increasing at negative bias. Taking all the data together we find a clear compensation effect of Az conduction around the Az denaturation temperature. This compensation can be understood by viewing the Az binding site as an electron trap, unless occupied by Cu(II), as in the native protein, with conduction of the native protein setting the upper transport efficiency limit.
Collapse
Affiliation(s)
- Nadav Amdursky
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel; Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - Lior Sepunaru
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel
| | - Sara Raichlin
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel; Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - Israel Pecht
- Departments of Immunology Weizmann Institute of Science Rehovot 76100 Israel
| | - Mordechai Sheves
- Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - David Cahen
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel
| |
Collapse
|
16
|
Amdursky N, Marchak D, Sepunaru L, Pecht I, Sheves M, Cahen D. Electronic transport via proteins. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:7142-61. [PMID: 25256438 DOI: 10.1002/adma.201402304] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 08/07/2014] [Indexed: 05/25/2023]
Abstract
A central vision in molecular electronics is the creation of devices with functional molecular components that may provide unique properties. Proteins are attractive candidates for this purpose, as they have specific physical (optical, electrical) and chemical (selective binding, self-assembly) functions and offer a myriad of possibilities for (bio-)chemical modification. This Progress Report focuses on proteins as potential building components for future bioelectronic devices as they are quite efficient electronic conductors, compared with saturated organic molecules. The report addresses several questions: how general is this behavior; how does protein conduction compare with that of saturated and conjugated molecules; and what mechanisms enable efficient conduction across these large molecules? To answer these questions results of nanometer-scale and macroscopic electronic transport measurements across a range of organic molecules and proteins are compiled and analyzed, from single/few molecules to large molecular ensembles, and the influence of measurement methods on the results is considered. Generalizing, it is found that proteins conduct better than saturated molecules, and somewhat poorer than conjugated molecules. Significantly, the presence of cofactors (redox-active or conjugated) in the protein enhances their conduction, but without an obvious advantage for natural electron transfer proteins. Most likely, the conduction mechanisms are hopping (at higher temperatures) and tunneling (below ca. 150-200 K).
Collapse
Affiliation(s)
- Nadav Amdursky
- Dept. of Materials & Interfaces, Weizmann Institute of Science, Rehovot, 76305, Israel
| | | | | | | | | | | |
Collapse
|
17
|
Zhang Y, Zhao Z, Fracasso D, Chiechi RC. Bottom-Up Molecular Tunneling Junctions Formed by Self-Assembly. Isr J Chem 2014. [DOI: 10.1002/ijch.201400033] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
18
|
Jiang L, Yuan L, Cao L, Nijhuis CA. Controlling leakage currents: the role of the binding group and purity of the precursors for self-assembled monolayers in the performance of molecular diodes. J Am Chem Soc 2014; 136:1982-91. [PMID: 24401113 DOI: 10.1021/ja411116n] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper describes that the performance of molecular diodes based on self-assembled monolayers (SAMs) depends on the type of anchoring group and purity of the precursors of these SAMs. The SAMs were formed on ultrasmooth template-stripped silver (Ag(TS)) surfaces, which served as the bottom-electrode, and a eutectic alloy of gallium-indium was used as the top-electrode. When these junctions incorporate SAMs of the form S(CH2)11Fc (≡ SC11Fc) derived from HSC11Fc, they are good molecular diodes and rectify currents with rectification ratios R (≡ |J(-1.0 V)|/|J(+1.0 V)|) of ∼1.0 × 10(2). Replacing the thiol by disulfide or thioacetate functionalities in the precursor resulted in molecular diodes with values of R close to unity. Cyclic voltammetry and angle resolved X-ray photoelectron spectroscopy indicated that the SAMs derived from the disulfide or thioacetate precursors have lower surface coverages and are more defective than SAMs derived from thiols. In the junctions these defective SAMs caused defects and increased the leakage currents. The purity of the thiol-precursor is also crucial: 3 or 5% of disulfide present in the thiol caused a 28 or 61% decrease in R, respectively, and >15% of disulfide lowered R to unity, while the yield in nonshorting junctions remained unchanged. Our results show that the type of binding group, and the puritiy of the thiols, are crucial parameters in the experimental design of molecular electronic devices to ensure optimal device performance by keeping leakage currents to a minimum.
Collapse
Affiliation(s)
- Li Jiang
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
| | | | | | | |
Collapse
|
19
|
Konermann L, Vahidi S, Sowole MA. Mass Spectrometry Methods for Studying Structure and Dynamics of Biological Macromolecules. Anal Chem 2013; 86:213-32. [DOI: 10.1021/ac4039306] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Siavash Vahidi
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Modupeola A. Sowole
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| |
Collapse
|
20
|
Amdursky N, Pecht I, Sheves M, Cahen D. Electron Transport via Cytochrome C on Si–H Surfaces: Roles of Fe and Heme. J Am Chem Soc 2013; 135:6300-6. [DOI: 10.1021/ja4015474] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Nadav Amdursky
- Departments
of Materials and Interfaces, ‡Organic Chemistry, and §Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Israel Pecht
- Departments
of Materials and Interfaces, ‡Organic Chemistry, and §Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mordechai Sheves
- Departments
of Materials and Interfaces, ‡Organic Chemistry, and §Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - David Cahen
- Departments
of Materials and Interfaces, ‡Organic Chemistry, and §Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| |
Collapse
|
21
|
Jett JE, Lederman D, Wollenberg LA, Li D, Flora DR, Bostick CD, Tracy TS, Gannett PM. Measurement of electron transfer through cytochrome P450 protein on nanopillars and the effect of bound substrates. J Am Chem Soc 2013; 135:3834-40. [PMID: 23427827 PMCID: PMC3876957 DOI: 10.1021/ja309104g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron transfer in cytochrome P450 enzymes is a fundamental process for activity. It is difficult to measure electron transfer in these enzymes because under the conditions typically used they exist in a variety of states. Using nanotechnology-based techniques, gold conducting nanopillars were constructed in an indexed array. The P450 enzyme CYP2C9 was attached to each of these nanopillars, and conductivity measurements made using conducting probe atomic force microscopy under constant force conditions. The conductivity measurements were made on CYP2C9 alone and with bound substrates, a bound substrate-effector pair, and a bound inhibitor. Fitting of the data with the Poole-Frenkel model indicates a correlation between the barrier height for electron transfer and the ease of CYP2C9-mediated metabolism of the bound substrates, though the spin state of iron is not well correlated. The approach described here should have broad application to the measurement of electron transfer in P450 enzymes and other metalloenzymes.
Collapse
Affiliation(s)
- John E. Jett
- West Virginia University, Basic Pharmaceutical Sciences, Morgantown, WV 26506-9530
| | - David Lederman
- West Virginia University, Department of Physics, Morgantown, WV 26506-6315
| | - Lance A. Wollenberg
- West Virginia University, Basic Pharmaceutical Sciences, Morgantown, WV 26506-9530
| | - Debin Li
- West Virginia University, Department of Physics, Morgantown, WV 26506-6315
| | - Darcy R. Flora
- University of Minnesota, College of Pharmacy, Minneapolis, MN, 55455
| | | | - Timothy S. Tracy
- University of Kentucky, College of Pharmacy, Lexington, KY 40536
| | - Peter M. Gannett
- West Virginia University, Basic Pharmaceutical Sciences, Morgantown, WV 26506-9530
| |
Collapse
|
22
|
Amdursky N, Ferber D, Pecht I, Sheves M, Cahen D. Redox activity distinguishes solid-state electron transport from solution-based electron transfer in a natural and artificial protein: cytochrome C and hemin-doped human serum albumin. Phys Chem Chem Phys 2013; 15:17142-9. [DOI: 10.1039/c3cp52885e] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|