1
|
Vione D, Minero C, Carena L. Fluorophores in surface freshwaters: importance, likely structures, and possible impacts of climate change. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:1429-1442. [PMID: 34490433 DOI: 10.1039/d1em00273b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fluorescence spectroscopy is one of the most useful techniques currently available for the characterisation of organic matter in natural water samples, because it combines easy availability of instrumentation, high sensitivity and limited requirements for sample treatment. The main fluorophores that can be found in natural waters are usually proteins (and/or free amino acids) and humic substances (humic and fulvic acids). The identification of these fluorescent compounds in water samples helps to obtain information about, among others, biological activity in the water body, possible transport of organic matter from soil, and the phenomenon of photobleaching that decreases both the absorbance and (usually) the fluorescence of natural organic matter. Interestingly, all these phenomena can be affected by climate change, which could alter to different extents the ratio between aquagenic and pedogenic fluorophores. Several events induced by warming in natural waters (and especially lake water) could enhance algal growth, thereby also enhancing the production of aquagenic organic matter. Intense precipitation events could increase the export of pedogenic material to surface waters, while photobleaching would be enhanced in the epilimnion of lakes when summer stratification becomes longer and more stable because of higher temperatures. Interestingly, photobleaching affects humic substances to a higher extent compared to protein-like material, thus protein fluorescence signals could be more preserved in stratified waters.
Collapse
Affiliation(s)
- Davide Vione
- Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy.
| | - Claudio Minero
- Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy.
| | - Luca Carena
- Dipartimento di Chimica, Università di Torino, Via P. Giuria 5, 10125 Torino, Italy.
| |
Collapse
|
2
|
Benzophenone based photostable fluorescent monoazo disperse dyes: Synthesis, AIE, viscosity, UPF and TD-DFT study. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-03732-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
3
|
Ghigo G, Vione D, Berto S. Experimental and theoretical study of the fluorescence emission of ferulic acid: Possible insights into the fluorescence properties of humic substances. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 228:117587. [PMID: 31707022 DOI: 10.1016/j.saa.2019.117587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/26/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
Ferulic acid ((E)-3-(4-hydroxy-3-methoxy-phenyl)prop-2-enoic acid, hereinafter FA) is a building block of plant cell walls that is commonly found in lignocellulose. As such, it is a potential component of humic substances produced by microbial degradation of plant spoils. The fluorescence excitation-emission matrix spectra of FA have an interesting humic-like shape, with bands that can be assimilated to the A and C regions of humic substances. Therefore, the study of FA photoluminescence might provide interesting insight into the still unknown processes that lay behind the fluorescence properties of humic compounds. FA is a weak diprotic acid that occurs in three different forms in aqueous solution (neutral H2FA, singly deprotonated HFA- and doubly deprotonated FA2-), which have slightly different absorption and emission properties. The "A-like" fluorescence emission of the FA species is accounted for by excitation from the ground singlet state S0 to singlet excited states higher than the first (S4 for H2FA, S5 for HFA-, and a state higher than S2 for FA2-), followed by radiationless deactivation to the first excited singlet state (S1), and by fluorescence emission according to the S1 → S0 transition. In contrast, the "C-like" emission is mainly caused by S0 → S1 excitation combined with S1 → S0 emission, but there is also a minor contribution from the S0 → S2 excitation that becomes significant for HFA-. The uneven variations with pH of the wavelengths of the maximum FA radiation absorption and fluorescence emission can be rationalised in the framework of the energy levels of the frontier (HOMO and LUMO) molecular orbitals of the different FA species. These levels are affected by charge interaction between the relevant electrons and the neutral (protonated) or negative (deprotonated) groups of each species.
Collapse
Affiliation(s)
- Giovanni Ghigo
- Department of Chemistry, University of Torino, Via Pietro Giuria 5,7, 10125, Torino, Italy
| | - Davide Vione
- Department of Chemistry, University of Torino, Via Pietro Giuria 5,7, 10125, Torino, Italy.
| | - Silvia Berto
- Department of Chemistry, University of Torino, Via Pietro Giuria 5,7, 10125, Torino, Italy.
| |
Collapse
|
4
|
Jamshad M, Knowles TJ, White SA, Ward DG, Mohammed F, Rahman KF, Wynne M, Hughes GW, Kramer G, Bukau B, Huber D. The C-terminal tail of the bacterial translocation ATPase SecA modulates its activity. eLife 2019; 8:48385. [PMID: 31246174 PMCID: PMC6620043 DOI: 10.7554/elife.48385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 06/26/2019] [Indexed: 11/25/2022] Open
Abstract
In bacteria, the translocation of proteins across the cytoplasmic membrane by the Sec machinery requires the ATPase SecA. SecA binds ribosomes and recognises nascent substrate proteins, but the molecular mechanism of nascent substrate recognition is unknown. We investigated the role of the C-terminal tail (CTT) of SecA in nascent polypeptide recognition. The CTT consists of a flexible linker (FLD) and a small metal-binding domain (MBD). Phylogenetic analysis and ribosome binding experiments indicated that the MBD interacts with 70S ribosomes. Disruption of the MBD only or the entire CTT had opposing effects on ribosome binding, substrate-protein binding, ATPase activity and in vivo function, suggesting that the CTT influences the conformation of SecA. Site-specific crosslinking indicated that F399 in SecA contacts ribosomal protein uL29, and binding to nascent chains disrupts this interaction. Structural studies provided insight into the CTT-mediated conformational changes in SecA. Our results suggest a mechanism for nascent substrate protein recognition.
Collapse
Affiliation(s)
- Mohammed Jamshad
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Timothy J Knowles
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Scott A White
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Douglas G Ward
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Fiyaz Mohammed
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Kazi Fahmida Rahman
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Max Wynne
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Gareth W Hughes
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ), ZMBH-DKFZ Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ), ZMBH-DKFZ Alliance, Heidelberg, Germany
| | - Damon Huber
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
5
|
Red Emitting Monoazo Disperse Dyes with Phenyl(1H-benzoimidazol-5-yl) Methanone as Inbuilt Photostabilizing Unit: Synthesis, Spectroscopic, Dyeing and DFT Studies. J Fluoresc 2018; 28:639-653. [PMID: 29619612 DOI: 10.1007/s10895-018-2226-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
Synthesis of three novel phenyl(1H-benzoimidazol-5-yl)methanone based fluorescent monoazo disperse dyes and their characterization by spectroscopic methods (1H NMR, 13C NMR, IR and MS) are presented. Insertion of phenyl(1H-benzoimidazol-5-yl)methanone moiety bring about induced fluorescence properties and enhanced photostability as compared to the previously reported analogues (CI Solvent Yellow 14, 4-diethylamino-2-hydroxy-1-diazobenzene and 7-(diethylamino)-4-hydroxy-3-(phenyldiazenyl)-2H-chromen-2-one). Synthesized phenyl(1H-benzoimidazol-5-yl)methanone based dyes exhibited red-shifted absorption maxima (497-516 nm), high molar extinction coefficients and are emitting in the far-red region (565-627 nm). Moreover, naphthalene-comprising dyes showed negative solvatochromism while N,N-diethylamine comprising dyes showed positive solvatochromism and are in good agreement with solvent polarity graphs and the computed energy levels of highest occupied and lowest unoccupied molecular orbitals. Synthesised dyes have better photostability (light fastness) and sublimation fastness on dyed polyester and nylon compared to reported analogues. DFT calculated energies, electrophilicity index and Frontier Molecular Orbitals (FMO's) enabled to evaluate the stabilities of azo and hydrazone forms of the dyes.
Collapse
|
6
|
Ghigo G, Berto S, Minella M, Vione D, Alladio E, Nurchi VM, Lachowicz J, Daniele PG. New insights into the protogenic and spectroscopic properties of commercial tannic acid: the role of gallic acid impurities. NEW J CHEM 2018. [DOI: 10.1039/c7nj04903j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Assessment of a protonation model for tannic acid and characterization of the spectral features of its protonated and dissociated species.
Collapse
Affiliation(s)
- G. Ghigo
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| | - S. Berto
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| | - M. Minella
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| | - D. Vione
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| | - E. Alladio
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| | - V. M. Nurchi
- Università di Cagliari
- Dipartimento di Scienze Chimiche e Geologiche
- Cittadella Universitaria
- I-09042 Cagliari
- Italy
| | - J. Lachowicz
- Università di Cagliari
- Dipartimento di Scienze Chimiche e Geologiche
- Cittadella Universitaria
- I-09042 Cagliari
- Italy
| | - P. G. Daniele
- Università di Torino
- Dipartimento di Chimica
- 10125 Torino
- Italy
| |
Collapse
|