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Chmykh Y, Nadeau JL. The use of fluorescence lifetime imaging (FLIM) for in situ microbial detection in complex mineral substrates. J Microsc 2024; 294:36-51. [PMID: 38230460 DOI: 10.1111/jmi.13264] [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: 08/01/2023] [Revised: 12/16/2023] [Accepted: 01/09/2024] [Indexed: 01/18/2024]
Abstract
The utility of fluorescence lifetime imaging microscopy (FLIM) for identifying bacteria in complex mineral matrices was investigated. Baseline signals from unlabelled Bacillus subtilis and Euglena gracilis, and Bacillus subtilis labelled with SYTO 9 were obtained using two-photon excitation at 730, 750 and 800 nm, identifying characteristic lifetimes of photosynthetic pigments, unpigmented cellular autofluorescence, and SYTO 9. Labelled and unlabelled B. subtilis were seeded onto marble and gypsum samples containing endolithic photosynthetic cyanobacteria and the ability to distinguish cells from mineral autofluorescence and nonspecific dye staining was examined in parallel with ordinary multichannel confocal imaging. It was found that FLIM enabled discrimination of SYTO 9 labelled cells from background, but that the lifetime of SYTO 9 was shorter in cells on minerals than in pure culture under our conditions. Photosynthetic microorganisms were easily observed using both FLIM and confocal. Unlabelled, nonpigmented bacteria showed weak signals that were difficult to distinguish from background when minerals were present, though cellular autofluorescence consistent with NAD(P)H could be seen in pure cultures, and phasor analysis permitted detection on rocks. Gypsum and marble samples showed similar autofluorescence profiles, with little autofluorescence in the yellow-to-red range. Lifetime or time-gated imaging may prove a useful tool for environmental microbiology. LAY DESCRIPTION: The standard method of bacterial enumeration is to label the cells with a fluorescent dye and count them under high-power fluorescence microscopy. However, this can be difficult when the cells are embedded in soil and rock due to fluorescence from the surrounding minerals and dye binding to ambiguous features of the substrate. The use of fluorescence lifetime imaging (FLIM) can disambiguate these signals and allow for improved detection of bacteria in environmental samples.
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Affiliation(s)
- Yekaterina Chmykh
- Department of Physics, Portland State University, Portland, Oregon, USA
| | - Jay L Nadeau
- Department of Physics, Portland State University, Portland, Oregon, USA
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Sirimatayanant S, Andruniów T. Benchmarking two-photon absorption strengths of rhodopsin chromophore models with CC3 and CCSD methodologies: An assessment of popular density functional approximations. J Chem Phys 2023; 158:094106. [PMID: 36889953 DOI: 10.1063/5.0135594] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
This work presents the investigations of the impact of an increasing electron correlation in the hierarchy of coupled-cluster methods, i.e., CC2, CCSD, and CC3, on two-photon absorption (2PA) strengths for the lowest excited state of the minimal rhodopsin's chromophore model-cis-penta-2,4-dieniminium cation (PSB3). For a larger chromophore's model [4-cis-hepta-2,4,6-trieniminium cation (PSB4)], CC2 and CCSD calculations of 2PA strengths were performed. Additionally, 2PA strengths predicted by some popular density functional theory (DFT) functionals differing in HF exchange contribution were assessed against the reference CC3/CCSD data. For PSB3, the accuracy of 2PA strengths increases in the following order: CC2 < CCSD < CC3, with the CC2 deviation from both higher-level methods exceeding 10% at 6-31+G* basis sets and 2% at aug-cc-pVDZ basis set. However, for PSB4, this trend is reversed and CC2-based 2PA strength is larger than the corresponding CCSD value. Among the DFT functionals investigated, CAM-B3LYP and BHandHLYP provide 2PA strengths in best compliance with reference data, however, with the error approaching an order of magnitude.
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Affiliation(s)
- Saruti Sirimatayanant
- Institute of Advanced Materials, Department of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Tadeusz Andruniów
- Institute of Advanced Materials, Department of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland
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Yao HD, Li DH, Gao RY, Zhou C, Wang W, Wang P, Shen JR, Kuang T, Zhang JP. A Possible Mechanism for Aggregation-Induced Chlorophyll Fluorescence Quenching in Light-Harvesting Complex II from the Marine Green Alga Bryopsis corticulans. J Phys Chem B 2022; 126:9580-9590. [PMID: 36356234 DOI: 10.1021/acs.jpcb.2c05823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The light-harvesting complex II of a green alga Bryopsis corticulans (B-LHCII) is peculiar in that it contains siphonein and siphonaxathin as carotenoid (Car). Since the S1 state of siphonein and siphonaxathin lies substantially higher than the Qy state of chlorophyll a (Chl a), the Chl a(Qy)-to-Car(S1) excitation energy transfer is unfeasible. To understand the photoprotective mechanism of algal photosynthesis, we investigated the influence of temperature on the excitation dynamics of B-LHCII in trimeric and aggregated forms. At room temperature, the aggregated form showed a 10-fold decrease in fluorescence intensity and lifetime than the trimeric form. Upon lowering the temperature, the characteristic 680 nm fluorescence (F-680) of B-LHCII in both forms exhibited systematic intensity enhancement and spectral narrowing; however, only the aggregated form showed a red emission extending over 690-780 nm (F-RE) with pronounced blueshift, lifetime prolongation, and intensity boost. The remarkable T-dependence of F-RE is ascribed to the Chl-Chl charge transfer (CT) species involved directly in the aggregation-induced Chl deactivation. The CT-quenching mechanism, which is considered to be crucial for B. corticulans photoprotection, draws strong support from the positive correlation of the Chl deactivation rate with the CT state population, as revealed by comparing the fluorescence dynamics of B-LHCII with that of the plant LHCII.
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Affiliation(s)
- Hai-Dan Yao
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, 100872 Beijing, China
| | - Dan-Hong Li
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, 100872 Beijing, China
| | - Rong-Yao Gao
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, 100872 Beijing, China
| | - Cuicui Zhou
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China
| | - Wenda Wang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China
| | - Peng Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, 100872 Beijing, China
| | - Jian-Ren Shen
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China.,Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Tingyun Kuang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, China
| | - Jian-Ping Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, 100872 Beijing, China
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Nowak J, Füller J, Walla PJ. Combined contributions of carotenoids and chlorophylls in two-photon spectra of photosynthetic pigment-protein complexes-A new way to quantify carotenoid dark state to chlorophyll energy transfer? J Chem Phys 2022; 156:191103. [PMID: 35597651 DOI: 10.1063/5.0089420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Transitions into the first excited state of carotenoids, Car S1, are optically forbidden in conventional one-photon excitation (OPE) but are possible via two-photon excitation (TPE). This can be used to quantify the amount of Car S1 to Chlorophyll (Chl) energy transfer in pigment-protein complexes and plants by observing the chlorophyll fluorescence intensity after TPE in comparison to the intensity observed after direct chlorophyll OPE. A parameter, ΦCoupling Car S1-Chl, can be derived that directly reflects relative differences or changes in the Car S1 → Chl energy transfer of different pigment-protein complexes and even living plants. However, very careful calibrations are necessary to ensure similar OPE and TPE excitation probabilities and transition energies. In plants, the exact same sample spot must be observed at the same time. All this is experimentally quite demanding. ΦCoupling Car S1-Chl also corrects intrinsically for direct chlorophyll TPE caused by larger chlorophyll excesses in the complexes, but recently it turned out that in certain TPE wavelengths ranges, its contribution can be quite large. Fortunately, this finding opens also the possibility of determining ΦCoupling Car S1-Chl in a much easier way by directly comparing values in TPE spectra observed at wavelengths that are either more dominated by Cars or Chls. This avoids tedious comparisons of OPE and TPE experiments and potentially allows measurement at even only two TPE wavelengths. Here, we explored this new approach to determine ΦCoupling Car S1-Chl directly from single TPE spectra and present first examples using known experimental spectra from Cars, Chl a, Chl b, LHC II, and PS 1.
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Affiliation(s)
- Julia Nowak
- Technische Universität Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Gaußstr. 17, 38106 Braunschweig, Germany
| | - Janin Füller
- Technische Universität Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Gaußstr. 17, 38106 Braunschweig, Germany
| | - Peter Jomo Walla
- Technische Universität Braunschweig, Institute for Physical and Theoretical Chemistry, Department for Biophysical Chemistry, Gaußstr. 17, 38106 Braunschweig, Germany
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Farhadian S, Hashemi-Shahraki F, Amirifar S, Asadpour S, Shareghi B, Heidari E, Shakerian B, Rafatifard M, Firooz AR. Malachite Green, the hazardous materials that can bind to Apo-transferrin and change the iron transfer. Int J Biol Macromol 2022; 194:790-799. [PMID: 34838577 DOI: 10.1016/j.ijbiomac.2021.11.126] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 02/08/2023]
Abstract
Different groups of synthetic dyes might lead to environmental pollution. The binding affinity among hazardous materials with biomolecules necessitates a detailed understanding of their binding properties. Malachite Green might induce a change in the iron transfer by Apo-transferrin. Spectroscopic studies showed malachite green oxalate (MGO) could form the apo-transferrin-MGO complex and change the Accessible Surface Area (ASA) of the key amino acids for iron transfer. According to the ASA results the accessible surface area of Tyrosine, Aspartate, and Histidine of apo-transferrin significantly were changed, which can be considered as a convincing reason for changing the iron transfer. Moreover, based on the fluorescence data MGO could quench the fluorescence intensity of apo-transferrin in a static quenching mechanism. The experimental and Molecular Dynamic simulation results represented that the binding process led to micro environmental changes, around tryptophan residues and altered the tertiary structure of apo-transferrin. The Circular Dichroism (CD) spectra result represented a decrease in the amount of the α-Helix, as well as, increase in the β-sheet volumes of the apo-transferrin structure. Moreover, FTIR spectroscopy results showed a hypochromic shift in the peaks of amide I and II. Molecular docking and MD simulation confirmed all the computational findings.
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Affiliation(s)
- Sadegh Farhadian
- Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, P. O. Box.115, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran.
| | - Fatemeh Hashemi-Shahraki
- Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, P. O. Box.115, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran
| | - Sogand Amirifar
- Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, P. O. Box.115, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran
| | - Saeid Asadpour
- Department of Chemistry, Faculty of Sciences, Shahrekord University, P. O. Box 115, Shahrekord, Iran.
| | - Behzad Shareghi
- Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, P. O. Box.115, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran
| | - Ehsan Heidari
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Behnam Shakerian
- Cardiovascular Diseases Research Department, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mohammad Rafatifard
- Exercise Science/Physiology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Ali Reza Firooz
- Department of Chemistry, University of Isfahan, Isfahan, Iran
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E/ Z Molecular Photoswitches Activated by Two-Photon Absorption: Comparison between Different Families. Molecules 2021; 26:molecules26237379. [PMID: 34885961 PMCID: PMC8659108 DOI: 10.3390/molecules26237379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/25/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022] Open
Abstract
Nonlinear optical techniques as two-photon absorption (TPA) have raised relevant interest within the last years due to the capability to excite chromophores with photons of wavelength equal to only half of the corresponding one-photon absorption energy. At the same time, its probability being proportional to the square of the light source intensity, it allows a better spatial control of the light-induced phenomenon. Although a consistent number of experimental studies focus on increasing the TPA cross section, very few of them are devoted to the study of photochemical phenomena induced by TPA. Here, we show a design strategy to find suitable E/Z photoswitches that can be activated by TPA. A theoretical approach is followed to predict the TPA cross sections related to different excited states of various photoswitches’ families, finally concluding that protonated Schiff-bases (retinal)-like photoswitches outperform compared to the others. The donor-acceptor substitution effect is therefore rationalized for the successful TPA activatable photoswitch, in order to maximize its properties, finally also forecasting a possible application in optogenetics. Some experimental measurements are also carried out to support our conclusions.
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Freixas VM, Wilhelm P, Nelson T, Hinderer F, Höger S, Tretiak S, Lupton JM, Fernandez-Alberti S. Excitation Energy Transfer between bodipy Dyes in a Symmetric Molecular Excitonic Seesaw. J Phys Chem A 2021; 125:8404-8416. [PMID: 34542292 DOI: 10.1021/acs.jpca.1c06332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We examine the redistribution of energy between electronic and vibrational degrees of freedom that takes place between a π-conjugated oligomer, a phenylene-butadiynylene, and two identical boron-dipyrromethene (bodipy) end-caps using femtosecond transient absorption spectroscopy, single-molecule spectroscopy, and nonadiabatic excited-state molecular dynamics (NEXMD) modeling techniques. The molecular structure represents an excitonic seesaw in that the excitation energy on the oligomer backbone can migrate to either one end-cap or the other, but not to both. The NEXMD simulations closely reproduce the characteristic time scale for redistribution of electronic and vibrational energy of 2.2 ps and uncover the vibrational modes contributing to the intramolecular relaxation. The calculations indicate that the dihedral angle between the bodipy dye and the oligomer change upon excitation of the oligomer. Single-molecule experiments reveal a difference in photoluminescence lifetime of the bodipy dyes depending on whether they are excited by direct absorption or by redistribution of energy from the backbone. This difference in lifetime may be attributed to the difference in dihedral angle. The simulations also suggest that a strong coupling can occur between the two end-caps, giving rise to a reversible shuttling of excitation energy between them. Strong coupling should lead to a pronounced loss in polarization memory of the fluorescence since the oligomer backbone tends to be slightly distorted and the two bodipy transition dipoles have different orientations. A sensitive single-molecule technique is presented to test for such coupling. However, although redistribution of electronic and vibrational energy between the end-caps can occur, it appears to be unidirectional and irreversible, suggesting that an additional localization mechanism is at play which is, as yet, not fully accounted for in the simulations.
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Affiliation(s)
- Victor M Freixas
- Departamento de Ciencia y Tecnologia, Universidad Nacional de Quilmes/CONICET, B1876BXD Bernal, Argentina
| | - Philipp Wilhelm
- Institut für Angewandte und Experimentelle Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Tammie Nelson
- Theoretical Division and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Florian Hinderer
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Sigurd Höger
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
| | - Sergei Tretiak
- Theoretical Division and Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - John M Lupton
- Institut für Angewandte und Experimentelle Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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Lokstein H, Renger G, Götze JP. Photosynthetic Light-Harvesting (Antenna) Complexes-Structures and Functions. Molecules 2021; 26:molecules26113378. [PMID: 34204994 PMCID: PMC8199901 DOI: 10.3390/molecules26113378] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 02/07/2023] Open
Abstract
Chlorophylls and bacteriochlorophylls, together with carotenoids, serve, noncovalently bound to specific apoproteins, as principal light-harvesting and energy-transforming pigments in photosynthetic organisms. In recent years, enormous progress has been achieved in the elucidation of structures and functions of light-harvesting (antenna) complexes, photosynthetic reaction centers and even entire photosystems. It is becoming increasingly clear that light-harvesting complexes not only serve to enlarge the absorption cross sections of the respective reaction centers but are vitally important in short- and long-term adaptation of the photosynthetic apparatus and regulation of the energy-transforming processes in response to external and internal conditions. Thus, the wide variety of structural diversity in photosynthetic antenna “designs” becomes conceivable. It is, however, common for LHCs to form trimeric (or multiples thereof) structures. We propose a simple, tentative explanation of the trimer issue, based on the 2D world created by photosynthetic membrane systems.
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Affiliation(s)
- Heiko Lokstein
- Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 12116 Prague, Czech Republic
- Correspondence:
| | - Gernot Renger
- Max-Volmer-Laboratorium, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Jan P. Götze
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany;
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