1
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Lynch P, Das A, Alam S, Rich CC, Frontiera RR. Mastering Femtosecond Stimulated Raman Spectroscopy: A Practical Guide. ACS PHYSICAL CHEMISTRY AU 2024; 4:1-18. [PMID: 38283786 PMCID: PMC10811773 DOI: 10.1021/acsphyschemau.3c00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/02/2023] [Accepted: 10/02/2023] [Indexed: 01/30/2024]
Abstract
Femtosecond stimulated Raman spectroscopy (FSRS) is a powerful nonlinear spectroscopic technique that probes changes in molecular and material structure with high temporal and spectral resolution. With proper spectral interpretation, this is equivalent to mapping out reactive pathways on highly anharmonic excited-state potential energy surfaces with femtosecond to picosecond time resolution. FSRS has been used to examine structural dynamics in a wide range of samples, including photoactive proteins, photovoltaic materials, plasmonic nanostructures, polymers, and a range of others, with experiments performed in multiple groups around the world. As the FSRS technique grows in popularity and is increasingly implemented in user facilities, there is a need for a widespread understanding of the methodology and best practices. In this review, we present a practical guide to FSRS, including discussions of instrumentation, as well as data acquisition and analysis. First, we describe common methods of generating the three pulses required for FSRS: the probe, Raman pump, and actinic pump, including a discussion of the parameters to consider when selecting a beam generation method. We then outline approaches for effective and efficient FSRS data acquisition. We discuss common data analysis techniques for FSRS, as well as more advanced analyses aimed at extracting small signals on a large background. We conclude with a discussion of some of the new directions for FSRS research, including spectromicroscopy. Overall, this review provides researchers with a practical handbook for FSRS as a technique with the aim of encouraging many scientists and engineers to use it in their research.
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Affiliation(s)
- Pauline
G. Lynch
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Aritra Das
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Shahzad Alam
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Christopher C. Rich
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Renee R. Frontiera
- Department
of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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2
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Chen C, Henderson JN, Ruchkin DA, Kirsh JM, Baranov MS, Bogdanov AM, Mills JH, Boxer SG, Fang C. Structural Characterization of Fluorescent Proteins Using Tunable Femtosecond Stimulated Raman Spectroscopy. Int J Mol Sci 2023; 24:11991. [PMID: 37569365 PMCID: PMC10418586 DOI: 10.3390/ijms241511991] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
The versatile functions of fluorescent proteins (FPs) as fluorescence biomarkers depend on their intrinsic chromophores interacting with the protein environment. Besides X-ray crystallography, vibrational spectroscopy represents a highly valuable tool for characterizing the chromophore structure and revealing the roles of chromophore-environment interactions. In this work, we aim to benchmark the ground-state vibrational signatures of a series of FPs with emission colors spanning from green, yellow, orange, to red, as well as the solvated model chromophores for some of these FPs, using wavelength-tunable femtosecond stimulated Raman spectroscopy (FSRS) in conjunction with quantum calculations. We systematically analyzed and discussed four factors underlying the vibrational properties of FP chromophores: sidechain structure, conjugation structure, chromophore conformation, and the protein environment. A prominent bond-stretching mode characteristic of the quinoidal resonance structure is found to be conserved in most FPs and model chromophores investigated, which can be used as a vibrational marker to interpret chromophore-environment interactions and structural effects on the electronic properties of the chromophore. The fundamental insights gained for these light-sensing units (e.g., protein active sites) substantiate the unique and powerful capability of wavelength-tunable FSRS in delineating FP chromophore properties with high sensitivity and resolution in solution and protein matrices. The comprehensive characterization for various FPs across a colorful palette could also serve as a solid foundation for future spectroscopic studies and the rational engineering of FPs with diverse and improved functions.
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Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA;
| | - J. Nathan Henderson
- Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; (J.N.H.); (J.H.M.)
| | - Dmitry A. Ruchkin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ulitsa Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; (D.A.R.); (M.S.B.); (A.M.B.)
| | - Jacob M. Kirsh
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA; (J.M.K.); (S.G.B.)
| | - Mikhail S. Baranov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ulitsa Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; (D.A.R.); (M.S.B.); (A.M.B.)
- Laboratory of Medicinal Substances Chemistry, Institute of Translational Medicine, Pirogov Russian National Research Medical University, Ostrovitianov 1, 117997 Moscow, Russia
| | - Alexey M. Bogdanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ulitsa Miklukho-Maklaya, 16/10, 117997 Moscow, Russia; (D.A.R.); (M.S.B.); (A.M.B.)
| | - Jeremy H. Mills
- Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA; (J.N.H.); (J.H.M.)
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Steven G. Boxer
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA; (J.M.K.); (S.G.B.)
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA;
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3
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Chen C, Zhang H, Zhang J, Ai HW, Fang C. Structural origin and rational development of bright red noncanonical variants of green fluorescent protein. Phys Chem Chem Phys 2023; 25:15624-15634. [PMID: 37211909 PMCID: PMC10330862 DOI: 10.1039/d3cp01315d] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The incorporation of noncanonical amino acids (ncAAs) into fluorescent proteins is promising for red-shifting their fluorescence and benefiting tissue imaging with deep penetration and low phototoxicity. However, ncAA-based red fluorescent proteins (RFPs) have been rare. The 3-aminotyrosine modified superfolder green fluorescent protein (aY-sfGFP) represents a recent advance, yet the molecular mechanism for its red-shifted fluorescence remains elusive while its dim fluorescence hinders applications. Herein, we implement femtosecond stimulated Raman spectroscopy to obtain structural fingerprints in the electronic ground state and reveal that aY-sfGFP possesses a GFP-like instead of RFP-like chromophore. Red color of aY-sfGFP intrinsically arises from a unique "double-donor" chromophore structure that raises ground-state energy and enhances charge transfer, notably differing from the conventional conjugation mechanism. We further developed two aY-sfGFP mutants (E222H and T203H) with significantly improved (∼12-fold higher) brightness by rationally restraining the chromophore's nonradiative decay through electronic and steric effects, aided by solvatochromic and fluorogenic studies of the model chromophore in solution. This study thus provides functional mechanisms and generalizable insights into ncAA-RFPs with an efficient route for engineering redder and brighter fluorescent proteins.
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Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA.
| | - Hao Zhang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
- Department of Molecular Physiology and Biological Physics and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
| | - Jing Zhang
- Department of Molecular Physiology and Biological Physics and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
| | - Hui-Wang Ai
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
- Department of Molecular Physiology and Biological Physics and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA
- The UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA.
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Xie J, Wang Z, Zhu R, Jiang J, Weng TC, Ren Y, Han S, Huang Y, Liu W. Investigation of Excited-State Intramolecular Proton Transfer and Structural Dynamics in Bis-Benzimidazole Derivative (BBM). Int J Mol Sci 2023; 24:ijms24119438. [PMID: 37298391 DOI: 10.3390/ijms24119438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
The bis-benzimidazole derivative (BBM) molecule, consisting of two 2-(2'-hydroxyphenyl) benzimidazole (HBI) halves, has been synthesized and successfully utilized as a ratiometric fluorescence sensor for the sensitive detection of Cu2+ based on enol-keto excited-state intramolecular proton transfer (ESIPT). In this study, we strategically implement femtosecond stimulated Raman spectroscopy and several time-resolved electronic spectroscopies, aided by quantum chemical calculations to investigate the detailed primary photodynamics of the BBM molecule. The results demonstrate that the ESIPT from BBM-enol* to BBM-keto* was observed in only one of the HBI halves with a time constant of 300 fs; after that, the rotation of the dihedral angle between the two HBI halves generated a planarized BBM-keto* isomer in 3 ps, leading to a dynamic redshift of BBM-keto* emission.
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Affiliation(s)
- Junhan Xie
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ziyu Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Ruixue Zhu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jiaming Jiang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tsu-Chien Weng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yi Ren
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shuhua Han
- Key Lab of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Yifan Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
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5
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Solaris J, Krueger TD, Chen C, Fang C. Photogrammetry of Ultrafast Excited-State Intramolecular Proton Transfer Pathways in the Fungal Pigment Draconin Red. Molecules 2023; 28:molecules28083506. [PMID: 37110741 PMCID: PMC10144053 DOI: 10.3390/molecules28083506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Proton transfer processes of organic molecules are key to charge transport and photoprotection in biological systems. Among them, excited-state intramolecular proton transfer (ESIPT) reactions are characterized by quick and efficient charge transfer within a molecule, resulting in ultrafast proton motions. The ESIPT-facilitated interconversion between two tautomers (PS and PA) comprising the tree fungal pigment Draconin Red in solution was investigated using a combination of targeted femtosecond transient absorption (fs-TA) and excited-state femtosecond stimulated Raman spectroscopy (ES-FSRS) measurements. Transient intensity (population and polarizability) and frequency (structural and cooling) dynamics of -COH rocking and -C=C, -C=O stretching modes following directed stimulation of each tautomer elucidate the excitation-dependent relaxation pathways, particularly the bidirectional ESIPT progression out of the Franck-Condon region to the lower-lying excited state, of the intrinsically heterogeneous chromophore in dichloromethane solvent. A characteristic overall excited-state PS-to-PA transition on the picosecond timescale leads to a unique "W"-shaped excited-state Raman intensity pattern due to dynamic resonance enhancement with the Raman pump-probe pulse pair. The ability to utilize quantum mechanics calculations in conjunction with steady-state electronic absorption and emission spectra to induce disparate excited-state populations in an inhomogeneous mixture of similar tautomers has broad implications for the modeling of potential energy surfaces and delineation of reaction mechanisms in naturally occurring chromophores. Such fundamental insights afforded by in-depth analysis of ultrafast spectroscopic datasets are also beneficial for future development of sustainable materials and optoelectronics.
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Affiliation(s)
- Janak Solaris
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA
| | - Taylor D Krueger
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA
| | - Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331, USA
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6
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Krueger TD, Tang L, Fang C. Delineating Ultrafast Structural Dynamics of a Green-Red Fluorescent Protein for Calcium Sensing. BIOSENSORS 2023; 13:bios13020218. [PMID: 36831983 PMCID: PMC9954042 DOI: 10.3390/bios13020218] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 05/14/2023]
Abstract
Fluorescent proteins (FPs) are indispensable tools for noninvasive bioimaging and sensing. Measuring the free cellular calcium (Ca2+) concentrations in vivo with genetically encodable FPs can be a relatively direct measure of neuronal activity due to the complex signaling role of these ions. REX-GECO1 is a recently developed red-green emission and excitation ratiometric FP-based biosensor that achieves a high dynamic range due to differences in the chromophore response to light excitation with and without calcium ions. Using steady-state electronic measurements (UV/Visible absorption and emission), along with time-resolved spectroscopic techniques including femtosecond transient absorption (fs-TA) and femtosecond stimulated Raman spectroscopy (FSRS), the potential energy surfaces of these unique biosensors are unveiled with vivid details. The ground-state structural characterization of the Ca2+-free biosensor via FSRS reveals a more spacious protein pocket that allows the chromophore to efficiently twist and reach a dark state. In contrast, the more compressed cavity within the Ca2+-bound biosensor results in a more heterogeneous distribution of chromophore populations that results in multi-step excited state proton transfer (ESPT) pathways on the sub-140 fs, 600 fs, and 3 ps timescales. These results enable rational design strategies to enlarge the spectral separation between the protonated/deprotonated forms and the Stokes shift leading to a larger dynamic range and potentially higher fluorescence quantum yield, which should be broadly applicable to the calcium imaging and biosensor communities.
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7
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Knorr J, Sülzner N, Geissler B, Spies C, Grandjean A, Kutta RJ, Jung G, Nuernberger P. Ultrafast transient absorption and solvation of a super-photoacid in acetoneous environments. PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES : OFFICIAL JOURNAL OF THE EUROPEAN PHOTOCHEMISTRY ASSOCIATION AND THE EUROPEAN SOCIETY FOR PHOTOBIOLOGY 2022; 21:2179-2192. [PMID: 36178669 DOI: 10.1007/s43630-022-00287-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/08/2022] [Indexed: 12/13/2022]
Abstract
The phenomenon of photoacidity, i.e., an increase in acidity by several orders of magnitude upon electronic excitation, is frequently encountered in aromatic alcohols capable of transferring a proton to a suitable acceptor. A promising new class of neutral super-photoacids based on pyranine derivatives has been shown to exhibit pronounced solvatochromic effects. To disclose the underlying mechanisms contributing to excited-state proton transfer (ESPT) and the temporal characteristics of solvation and ESPT, we scrutinize the associated ultrafast dynamics of the strongest photoacid of this class, namely tris(1,1,1,3,3,3-hexafluoropropan-2-yl)8-hydroxypyrene-1,3,6-trisulfonate, in acetoneous environment, thereby finding experimental evidence for ESPT even under these adverse conditions for proton transfer. Juxtaposing results from time-correlated single-photon counting and femtosecond transient absorption measurements combined with a complete decomposition of all signal components, i.e., absorption of ground and excited states as well as stimulated emission, we disclose dynamics of solvation, rotational diffusion, and radiative relaxation processes in acetone and identify the relevant steps of ESPT along with the associated time scales.
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Affiliation(s)
- Johannes Knorr
- Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany.,Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Paul-Gordan-Straße 6, 91052, Erlangen, Germany
| | - Niklas Sülzner
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780, Bochum, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Bastian Geissler
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Christian Spies
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany.,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Alexander Grandjean
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Roger Jan Kutta
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany
| | - Gregor Jung
- Biophysikalische Chemie, Universität des Saarlandes, 66123, Saarbrücken, Germany
| | - Patrick Nuernberger
- Institut für Physikalische und Theoretische Chemie, Universität Regensburg, Universitätsstraße 31, 95053, Regensburg, Germany. .,Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany.
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8
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Nandi R, Amdursky N. The Dual Use of the Pyranine (HPTS) Fluorescent Probe: A Ground-State pH Indicator and an Excited-State Proton Transfer Probe. Acc Chem Res 2022; 55:2728-2739. [PMID: 36053265 PMCID: PMC9494743 DOI: 10.1021/acs.accounts.2c00458] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Indexed: 01/19/2023]
Abstract
Molecular fluorescent probes are an essential experimental tool in many fields, ranging from biology to chemistry and materials science, to study the localization and other environmental properties surrounding the fluorescent probe. Thousands of different molecular fluorescent probes can be grouped into different families according to their photophysical properties. This Account focuses on a unique class of fluorescent probes that distinguishes itself from all other probes. This class is termed photoacids, which are molecules exhibiting a change in their acid-base transition between the ground and excited states, resulting in a large change in their pKa values between these two states, which is thermodynamically described using the Förster cycle. While there are many different photoacids, we focus only on pyranine, which is the most used photoacid, with pKa values of ∼7.4 and ∼0.4 for its ground and excited states, respectively. Such a difference between the pKa values is the basis for the dual use of the pyranine fluorescent probe. Furthermore, the protonated and deprotonated states of pyranine absorb and emit at different wavelengths, making it easy to focus on a specific state. Pyranine has been used for decades as a fluorescent pH indicator for physiological pH values, which is based on its acid-base equilibrium in the ground state. While the unique excited-state proton transfer (ESPT) properties of photoacids have been explored for more than a half-century, it is only recently that photoacids and especially pyranine have been used as fluorescent probes for the local environment of the probe, especially the hydration layer surrounding it and related proton diffusion properties. Such use of photoacids is based on their capability for ESPT from the photoacid to a nearby proton acceptor, which is usually, but not necessarily, water. In this Account, we detail the photophysical properties of pyranine, distinguishing between the processes in the ground state and the ones in the excited state. We further review the different utilization of pyranine for probing different properties of the environment. Our main perspective is on the emerging use of the ESPT process for deciphering the hydration layer around the probe and other parameters related to proton diffusion taking place while the molecule is in the excited state, focusing primarily on bio-related materials. Special attention is given to how to perform the experiments and, most importantly, how to interpret their results. We also briefly discuss the breadth of possibilities in making pyranine derivatives and the use of pyranine for controlling dynamic reactions.
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Affiliation(s)
- Ramesh Nandi
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
| | - Nadav Amdursky
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Haifa 3200003, Israel
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Kim KI, Tang L, Muratli JM, Fang C, Ji X. A Graphite∥PTCDI Aqueous Dual-Ion Battery. CHEMSUSCHEM 2022; 15:e202102394. [PMID: 35132831 DOI: 10.1002/cssc.202102394] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/05/2021] [Indexed: 06/14/2023]
Abstract
A full cell chemistry of aqueous dual-ion battery (DIB) was reported, comprising the graphite cathode and 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) as the anode. This DIB employed a mixture aqueous electrolyte: 5 m tributylmethylammonium (TBMA) chloride plus 5 m MgCl2 , where [MgCl3 ]- and TBMA+ serve as the charge carriers for cathode and anode of the DIB, respectively. This novel full cell exhibited a specific capacity of around 41 mAh g-1 based on the total active mass of both electrodes with an average operation voltage of 1.45 V and stable cycling for 400 cycles.
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Affiliation(s)
- Keun-Il Kim
- Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331-4003, United States
| | - Longteng Tang
- Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331-4003, United States
| | - Jesse M Muratli
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331-5503, United States
| | - Chong Fang
- Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331-4003, United States
| | - Xiulei Ji
- Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331-4003, United States
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10
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Dobryakov AL, Krohn OA, Quick M, Ioffe I, Kovalenko SA. Positive and Negative Signal and Line-Shape in Stimulated Raman Spectroscopy: Resonance Femtosecond Raman Spectra of Diphenylbutadiene. J Chem Phys 2022; 156:084304. [DOI: 10.1063/5.0075116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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11
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Wang Y, Ruan Y, Du B, Li J, Ebendorff-Heidepriem H, Wang X. Real-time Raman analysis of the hydrolysis of formaldehyde oligomers for enhanced collagen fixation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 264:120285. [PMID: 34455375 DOI: 10.1016/j.saa.2021.120285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Formaldehyde (FA) is widely applied as a fixative for proteins such as collagen. Current studies have confirmed that the reversible oligomer-to-monomer equilibrium of FA in aqueous solution and the proportion of FA monomer is a significant factor affecting tissue fixation. Since the hydrolysis of FA oligomers is a dynamic process affected jointly by different factors, its real time monitoring has proved to be challenging. In this work, by utilizing the well-established Raman technique as an analytical platform, we identified the factors affecting the hydrolysis of FA oligomers by rationally examining the νs (OCO) and νas (OCO) modes with varying conditions, such as time, pH, temperature, and FA concentration. The optimized conditions of the highest hydrolysis rate of oligomers into monomers for fixation on collagen and tissues have been found to be relatively low FA concentration (≤5%) in phosphate-buffered saline at pH 9.0 in room temperature. In order to compare the fixation quality of the optimized conditions to that of the conventional conditions used by current medical practices (4% FA concentration in tap water under room temperature), Raman spectroscopy and chemical derivatization methods with o-phthalaldehyde and fluorescent probe FAP-1 have been investigated, and our results revealed that the FA molecules under our optimized conditions have reacted with at least 15% more amino groups within collagen compared to those under the conventional conditions mentioned above. This study provides direct evidence of the FA equilibrium in solution by Raman spectroscopy, which could be applied for the optimal use of FA in medicine, even at an industrial scale.
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Affiliation(s)
- Yansong Wang
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China; Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, and ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, Adelaide 5005, Australia
| | - Yinlan Ruan
- School of Electronic Engineering and Automation, Guilin University of Electronic Technology, Guilin 541004, China; Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, and ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, Adelaide 5005, Australia.
| | - Bobo Du
- Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, and ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, Adelaide 5005, Australia; The Key Laboratory of Physical Electronics and Devices of Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Ji Li
- Institute of Biomass & Functional Materials (IBFM), College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China
| | - Heike Ebendorff-Heidepriem
- Institute for Photonics and Advanced Sensing (IPAS), School of Physical Sciences, and ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, Adelaide 5005, Australia
| | - Xuechuan Wang
- College of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China; Institute of Biomass & Functional Materials (IBFM), College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China.
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12
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Grandjean A, Pérez Lustres JL, Jung G. Solvent‐Controlled Intermolecular Proton‐Transfer Follows an Irreversible Eigen‐Weller Model from fs to ns. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Alexander Grandjean
- Biophysikalische Chemie Universität des Saarlandes FR Chemie, Gebäude B2 2, Postfach 151150 D-66041 Saarbrücken Germany
| | - J. Luis Pérez Lustres
- Current Address: Fachbereich Physik Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
- Experimental work conducted at former affiliation Physikalisch Chemisches Institut Universität Heidelberg Im Neuenheimer Feld 229 D-69120 Heidelberg Germany
| | - Gregor Jung
- Biophysikalische Chemie Universität des Saarlandes FR Chemie, Gebäude B2 2, Postfach 151150 D-66041 Saarbrücken Germany
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13
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Jeon K, Jen M, Lee S, Jang T, Pang Y. Intramolecular Charge Transfer of 1-Aminoanthraquinone and Ultrafast Solvation Dynamics of Dimethylsulfoxide. Int J Mol Sci 2021; 22:ijms222111926. [PMID: 34769357 PMCID: PMC8584543 DOI: 10.3390/ijms222111926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
The intramolecular charge transfer (ICT) of 1-aminoanthraquinone (AAQ) in the excited state strongly depends on its solvent properties, and the twisted geometry of its amino group has been recommended for the twisted ICT (TICT) state by recent theoretical works. We report the transient Raman spectra of AAQ in a dimethylsulfoxide (DMSO) solution by femtosecond stimulated Raman spectroscopy to provide clear experimental evidence for the TICT state of AAQ. The ultrafast (~110 fs) TICT dynamics of AAQ were observed from the major vibrational modes of AAQ including the νC-N + δCH and νC=O modes. The coherent oscillations in the vibrational bands of AAQ strongly coupled to the nuclear coordinate for the TICT process have been observed, which showed its anharmonic coupling to the low frequency out of the plane deformation modes. The vibrational mode of solvent DMSO, νS=O showed a decrease in intensity, especially in the hydrogen-bonded species of DMSO, which clearly shows that the solvation dynamics of DMSO, including hydrogen bonding, are crucial to understanding the reaction dynamics of AAQ with the ultrafast structural changes accompanying the TICT.
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14
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Santos EM, Sheng W, Esmatpour Salmani R, Tahmasebi Nick S, Ghanbarpour A, Gholami H, Vasileiou C, Geiger JH, Borhan B. Design of Large Stokes Shift Fluorescent Proteins Based on Excited State Proton Transfer of an Engineered Photobase. J Am Chem Soc 2021; 143:15091-15102. [PMID: 34516091 DOI: 10.1021/jacs.1c05039] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The incredible potential for fluorescent proteins to revolutionize biology has inspired the development of a variety of design strategies to address an equally broad range of photophysical characteristics, depending on potential applications. Of these, fluorescent proteins that simultaneously exhibit high quantum yield, red-shifted emission, and wide separation between excitation and emission wavelengths (Large Stokes Shift, LSS) are rare. The pursuit of LSS systems has led to the formation of a complex, obtained from the marriage of a rationally engineered protein (human cellular retinol binding protein II, hCRBPII) and different fluorogenic molecules, capable of supporting photobase activity. The large increase in basicity upon photoexcitation leads to protonation of the fluorophore in the excited state, dramatically red-shifting its emission, leading to an LSS protein/fluorophore complex. Essential for selective photobase activity is the intimate involvement of the target protein structure and sequence that enables Excited State Proton Transfer (ESPT). The potential power and usefulness of the strategy was demonstrated in live cell imaging of human cell lines.
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Affiliation(s)
- Elizabeth M Santos
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - Wei Sheng
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | | | - Setare Tahmasebi Nick
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - Alireza Ghanbarpour
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - Hadi Gholami
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - Chrysoula Vasileiou
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - James H Geiger
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
| | - Babak Borhan
- Michigan State University, Department of Chemistry, East Lansing, Michigan 48824, United States
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15
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Chiariello MG, Donati G, Raucci U, Perrella F, Rega N. Structural Origin and Vibrational Fingerprints of the Ultrafast Excited State Proton Transfer of the Pyranine-Acetate Complex in Aqueous Solution. J Phys Chem B 2021; 125:10273-10281. [PMID: 34472354 DOI: 10.1021/acs.jpcb.1c05590] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The excited state proton transfer (ESPT) reaction from the photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS or pyranine) to an acetate molecule has been investigated in explicit aqueous solution via excited state ab initio molecular dynamics simulations based on hybrid quantum/molecular mechanics (QM/MM) potentials. In all the trajectories, the direct proton transfer has been observed in the excited state within 1 ps. We find that the initial structural configuration extracted from the ground state distribution strongly affects the ESPT kinetics. Indeed, the relative orientation of the proton donor-acceptor pair and the presence of a water molecule hydrogen bonded to the phenolic acid group of the pyranine are the key factors to facilitate the ESPT. Furthermore, we analyze the vibrational fingerprints of the ESPT reaction, reproducing the blue shift of the acetate CO stretching (COac), from 1666 to 1763 cm-1 testifying the transformation of acetate to acetic acid. Finally, our findings suggest that the acetate CC stretching (CCac) is also sensitive to the progress of the ESPT reaction. The CCac stretching is indeed ruled by the two vibrational modes (928 and 1426 cm-1), that in the excited state are alternately activated when the proton is shared or bound to the donor/acceptor, respectively.
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Affiliation(s)
- Maria Gabriella Chiariello
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Greta Donati
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Umberto Raucci
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Fulvio Perrella
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Nadia Rega
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy.,CRIB Center for Advanced Biomaterials for Healthcare, Piazzale Tecchio, 80-80125 Napoli, Italy
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16
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An Engineered Biliverdin-Compatible Cyanobacteriochrome Enables a Unique Ultrafast Reversible Photoswitching Pathway. Int J Mol Sci 2021; 22:ijms22105252. [PMID: 34065754 PMCID: PMC8156171 DOI: 10.3390/ijms22105252] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/09/2021] [Accepted: 05/14/2021] [Indexed: 11/17/2022] Open
Abstract
Cyanobacteriochromes (CBCRs) are promising optogenetic tools for their diverse absorption properties with a single compact cofactor-binding domain. We previously uncovered the ultrafast reversible photoswitching dynamics of a red/green photoreceptor AnPixJg2, which binds phycocyanobilin (PCB) that is unavailable in mammalian cells. Biliverdin (BV) is a mammalian cofactor with a similar structure to PCB but exhibits redder absorption. To improve the AnPixJg2 feasibility in mammalian applications, AnPixJg2_BV4 with only four mutations has been engineered to incorporate BV. Herein, we implemented femtosecond transient absorption (fs-TA) and ground state femtosecond stimulated Raman spectroscopy (GS-FSRS) to uncover transient electronic dynamics on molecular time scales and key structural motions responsible for the photoconversion of AnPixJg2_BV4 with PCB (Bpcb) and BV (Bbv) cofactors in comparison with the parent AnPixJg2 (Apcb). Bpcb adopts the same photoconversion scheme as Apcb, while BV4 mutations create a less bulky environment around the cofactor D ring that promotes a faster twist. The engineered Bbv employs a reversible clockwise/counterclockwise photoswitching that requires a two-step twist on ~5 and 35 picosecond (ps) time scales. The primary forward Pfr → Po transition displays equal amplitude weights between the two processes before reaching a conical intersection. In contrast, the primary reverse Po → Pfr transition shows a 2:1 weight ratio of the ~35 ps over 5 ps component, implying notable changes to the D-ring-twisting pathway. Moreover, we performed pre-resonance GS-FSRS and quantum calculations to identify the Bbv vibrational marker bands at ~659,797, and 1225 cm-1. These modes reveal a stronger H-bonding network around the BV cofactor A ring with BV4 mutations, corroborating the D-ring-dominant reversible photoswitching pathway in the excited state. Implementation of BV4 mutations in other PCB-binding GAF domains like AnPixJg4, AM1_1870g3, and NpF2164g5 could promote similar efficient reversible photoswitching for more directional bioimaging and optogenetic applications, and inspire other bioengineering advances.
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17
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Wei J, Wu Y, Pu R, Shi L, Jiang J, Du J, Guo Z, Huang Y, Liu W. Tracking Ultrafast Structural Dynamics in a Dual-Emission Anti-Kasha-Active Fluorophore Using Femtosecond Stimulated Raman Spectroscopy. J Phys Chem Lett 2021; 12:4466-4473. [PMID: 33955767 DOI: 10.1021/acs.jpclett.1c00202] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The anti-Kasha process provides the possibility of using high-energy excited states to develop novel applications. Our previous research (Nature communications, 2020, 11, 793) has demonstrated a dual-emission anti-Kasha-active fluorophore for bioimaging application, which exhibits near-infrared emissions from the S1 state and visible anti-Kasha emissions from the S2 state. Here, we applied tunable blue-side femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption spectroscopy, assisted by quantum calculations, to reveal the anti-Kasha dual emission mechanism, in which the emergence of two fluorescing states is due to the retardation of internal conversion from the S2 state to the S1 state. It has been demonstrated that the facts of anti-Kasha high-energy emission are commonly attributed to a large energy gap between the two excited states, leading to a decrease in the internal conversion rate due to a poor Franck-Condon factor. In this study, analysis of the calculation and FSRS experimental results provide us further insight into the dual-emission anti-Kasha mechanism, where the observation of hydrogen out-of-plane Raman modes from FSRS suggested that, in addition to the energy-gap law, the initial photoinduced molecular conformational change plays a key role in influencing the rate of internal conversion.
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Affiliation(s)
- Jingle Wei
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Yuexia Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Ruihua Pu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Limin Shi
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jiaming Jiang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Juan Du
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Zhiqian Guo
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yifan Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
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18
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Chiariello MG, Raucci U, Donati G, Rega N. Water-Mediated Excited State Proton Transfer of Pyranine-Acetate in Aqueous Solution: Vibrational Fingerprints from Ab Initio Molecular Dynamics. J Phys Chem A 2021; 125:3569-3578. [PMID: 33900071 PMCID: PMC8279639 DOI: 10.1021/acs.jpca.1c00692] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
In this work, we
simulate the excited state proton transfer (ESPT)
reaction involving the pyranine photoacid and an acetate molecule
as proton acceptor, connected by a bridge water molecule. We employ
ab initio molecular dynamics combined with an hybrid quantum/molecular
mechanics (QM/MM) framework. Furthermore, a time-resolved vibrational
analysis based on the wavelet-transform allows one to identify two
low frequency vibrational modes that are fingerprints of the ESPT
event: a ring wagging and ring breathing. Their composition suggests
their key role in optimizing the structure of the proton donor–acceptor
couple and promoting the ESPT event. We find that the choice of the
QM/MM partition dramatically affects the photoinduced reactivity of
the system. The QM subspace was gradually extended including the water
molecules directly interacting with the pyranine–water–acetate
system. Indeed, the ESPT reaction takes place when the hydrogen bond
network around the reactive system is taken into account at full QM
level.
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Affiliation(s)
- Maria Gabriella Chiariello
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Umberto Raucci
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Greta Donati
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Nadia Rega
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy.,Centro Interdipartimentale di Ricerca sui Biomateriali (CRIB) Piazzale Tecchio, Largo Barsanti e Matteucci, I-80125 Napoli, Italy
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19
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Zhang W, Xu W, Zhang G, Kong J, Niu X, Chan JMW, Liu W, Xia A. Direct Tracking Excited-State Intramolecular Charge Redistribution of Acceptor-Donor-Acceptor Molecule by Means of Femtosecond Stimulated Raman Spectroscopy. J Phys Chem B 2021; 125:4456-4464. [PMID: 33902280 DOI: 10.1021/acs.jpcb.1c01742] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Symmetric quadrupolar molecules generally exhibit apolar ground states and dipolar excited states in a polar environment, which is explained by the excited state evolution from initial charge delocalization over all molecules to localization on one branch of the molecules after a femtosecond pulse excitation. However, direct observation of excited-state charge redistribution (delocalization/localization) is hardly accessible. Here, the intramolecular charge delocalization/localization character of a newly synthesized acceptor-donor-acceptor molecule (ADA) has been intensively investigated by femtosecond stimulated Raman scattering (FSRS) together with femtosecond transient absorption (fs-TA) spectroscopy. By tracking the excited state Raman spectra of the specific alkynyl (-C≡C-) bonds at each branch of ADA, we found that the nature of the relaxed S1 state is strongly governed by solvent polarity: symmetric delocalized intramolecular charge transfer (ICT) characters occurred in apolar solvent, whereas the asymmetric localized ICT characters appeared in polar solvent because of solvation. The solvation dynamics of ADA extracted from fs-TA is consistent with the time constants obtained by FSRS, but the FSRS clearly tracks the excited state intramolecular charge transfer delocalization/localization.
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Affiliation(s)
- Wei Zhang
- School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.,Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R China.,University of Chinese Academy of Sciences, Beijing 100049, P. R China
| | - Wenqi Xu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China.,STU & SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, P. R. China
| | - Guoxian Zhang
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Pvt., Ottawa, Ontario K1N 6N5, Canada
| | - Jie Kong
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R China.,University of Chinese Academy of Sciences, Beijing 100049, P. R China
| | - Xinmiao Niu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R China.,University of Chinese Academy of Sciences, Beijing 100049, P. R China
| | - Julian M W Chan
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Pvt., Ottawa, Ontario K1N 6N5, Canada
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China.,STU & SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, P. R. China
| | - Andong Xia
- School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.,Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R China
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20
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Tachibana SR, Tang L, Chen C, Zhu L, Takeda Y, Fushimi K, Seevers TK, Narikawa R, Sato M, Fang C. Transient electronic and vibrational signatures during reversible photoswitching of a cyanobacteriochrome photoreceptor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 250:119379. [PMID: 33401182 DOI: 10.1016/j.saa.2020.119379] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/12/2020] [Accepted: 12/19/2020] [Indexed: 06/12/2023]
Abstract
Cyanobacteriochromes (CBCRs) are an emerging class of photoreceptors that are distant relatives of the phytochromes family. Unlike phytochromes, CBCRs have gained popularity in optogenetics due to their highly diverse spectral properties spanning the UV to near-IR region and only needing a single compact binding domain. AnPixJg2 is a CBCR that can reversibly photoswitch between its red-absorbing (15ZPr) and green-absorbing (15EPg) forms of the phycocyanobilin (PCB) cofactor. To reveal primary events of photoconversion, we implemented femtosecond transient absorption spectroscopy with a homemade LED box and a miniature peristaltic pump flow cell to track transient electronic responses of the photoexcited AnPixJg2 on molecular time scales. The 525 nm laser-induced Pg-to-Pr reverse conversion exhibits a ~3 ps excited-state lifetime before reaching the conical intersection (CI) and undergoing further relaxation on the 30 ps time scale to generate a long-lived Lumi-G ground state intermediate en route to Pr. The 650 nm laser-induced Pr-to-Pg forward conversion is less efficient than reverse conversion, showing a longer-lived excited state which requires two steps with ~13 and 217 ps time constants to enter the CI region. Furthermore, using a tunable ps Raman pump with broadband Raman probe on both the Stokes and anti-Stokes sides, we collected the pre-resonance ground-state femtosecond stimulated Raman spectroscopy (GS-FSRS) data with mode assignments aided by quantum calculations. Key vibrational marker bands at ~850, 1050, 1615, and 1649 cm-1 of the Pr conformer exhibit a notable blueshift to those of the Pg conformer inside AnPixJg2, reflecting the PCB chromophore terminal D (major) and A (minor) ring twist along the primary photoswitching reaction coordinate. This integrated ultrafast spectroscopy and computational platform has the potential to elucidate photochemistry and photophysics of more CBCRs and photoactive proteins in general, providing the highly desirable mechanistic insights to facilitate the rational design of functional molecular sensors and devices.
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Affiliation(s)
- Sean R Tachibana
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Longteng Tang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Liangdong Zhu
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Yuka Takeda
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan
| | - Keiji Fushimi
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan
| | - Travis K Seevers
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States
| | - Rei Narikawa
- Graduate School of Integrated Science and Technology, Shizuoka University, 422-8529 Shizuoka, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 332-0012 Saitama, Japan
| | - Moritoshi Sato
- Graduate School of Arts and Sciences, University of Tokyo, 153-8902 Tokyo, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, 332-0012 Saitama, Japan
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, United States.
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21
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Legrand A, Liu LH, Royla P, Aoyama T, Craig GA, Carné-Sánchez A, Urayama K, Weigand JJ, Lin CH, Furukawa S. Spatiotemporal Control of Supramolecular Polymerization and Gelation of Metal-Organic Polyhedra. J Am Chem Soc 2021; 143:3562-3570. [PMID: 33646776 DOI: 10.1021/jacs.1c00108] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In coordination-based supramolecular materials such as metallogels, simultaneous temporal and spatial control of their assembly remains challenging. Here, we demonstrate that the combination of light with acids as stimuli allows for the spatiotemporal control over the architectures, mechanical properties, and shape of porous soft materials based on metal-organic polyhedra (MOPs). First, we show that the formation of a colloidal gel network from a preformed kinetically trapped MOP solution can be triggered upon addition of trifluoroacetic acid (TFA) and that acid concentration determines the reaction kinetics. As determined by time-resolved dynamic light scattering, UV-vis absorption, and 1H NMR spectroscopies and rheology measurements, the consequences of the increase in acid concentration are (i) an increase in the cross-linking between MOPs; (ii) a growth in the size of the colloidal particles forming the gel network; (iii) an increase in the density of the colloidal network; and (iv) a decrease in the ductility and stiffness of the resulting gel. We then demonstrate that irradiation of a dispersed photoacid generator, pyranine, allows the spatiotemporal control of the gel formation by locally triggering the self-assembly process. Using this methodology, we show that the gel can be patterned into a desired shape. Such precise positioning of the assembled structures, combined with the stable and permanent porosity of MOPs, could allow their integration into devices for applications such as sensing, separation, catalysis, or drug release.
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Affiliation(s)
- Alexandre Legrand
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Li-Hao Liu
- Department of Chemistry, Chung-Yuan Christian University, Chung Li, 32023 Taiwan
| | - Philipp Royla
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
| | - Takuma Aoyama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Gavin A Craig
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Arnau Carné-Sánchez
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Jan J Weigand
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany
| | - Chia-Her Lin
- Department of Chemistry, Chung-Yuan Christian University, Chung Li, 32023 Taiwan
| | - Shuhei Furukawa
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.,Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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22
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Raucci U, Chiariello MG, Rega N. Modeling Excited-State Proton Transfer to Solvent: A Dynamics Study of a Super Photoacid with a Hybrid Implicit/Explicit Solvent Model. J Chem Theory Comput 2020; 16:7033-7043. [PMID: 33112132 PMCID: PMC8016186 DOI: 10.1021/acs.jctc.0c00782] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
The rapid growth of time-resolved
spectroscopies and the theoretical
advances in ab initio molecular dynamics (AIMD) pave the way to look
at the real-time molecular motion following the electronic excitation.
Here, we exploited the capabilities of AIMD combined with a hybrid
implicit/explicit model of solvation to investigate the ultrafast
excited-state proton transfer (ESPT) reaction of a super photoacid,
known as QCy9, in water solution. QCy9 transfers a proton to a water
solvent molecule within 100 fs upon the electronic excitation in aqueous
solution, and it is the strongest photoacid reported in the literature
so far. Because of the ultrafast kinetics, it has been experimentally
hypothesized that the ESPT escapes the solvent dynamics control (Huppert
et al., J. Photochem. Photobiol. A2014,277, 90). The sampling of the solvent configuration
space on the ground electronic state is the first key step toward
the simulation of the ESPT event. Therefore, several configurations
in the Franck–Condon region, describing an average solvation,
were chosen as starting points for the excited-state dynamics. In
all cases, the excited-state evolution spontaneously leads to the
proton transfer event, whose rate is strongly dependent on the hydrogen
bond network around the proton acceptor solvent molecule. Our study
revealed that the explicit representation at least of three solvation
shells around the proton acceptor molecule is necessary to stabilize
the excess proton. Furthermore, the analysis of the solvent molecule
motions in proximity of the reaction site suggested that even in the
case of the strongest photoacid, the ESPT is actually assisted by
the solvation dynamics of the first and second solvation shells of
the water accepting molecule.
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Affiliation(s)
- Umberto Raucci
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia, I-80126 Napoli, Italy
| | - Maria Gabriella Chiariello
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia, I-80126 Napoli, Italy
| | - Nadia Rega
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia, I-80126 Napoli, Italy.,CRIB, Centro Interdipartimentale di Ricerca sui Biomateriali, Piazzale Tecchio, I-80125 Napoli, Italy
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23
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Chiariello MG, Donati G, Rega N. Time-Resolved Vibrational Analysis of Excited State Ab Initio Molecular Dynamics to Understand Photorelaxation: The Case of the Pyranine Photoacid in Aqueous Solution. J Chem Theory Comput 2020; 16:6007-6013. [PMID: 32955870 PMCID: PMC8011922 DOI: 10.1021/acs.jctc.0c00810] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
![]()
We
present a novel time-resolved vibrational analysis for studying
photoinduced nuclear relaxation. Generalized modes velocities are
defined from ab initio molecular dynamics and wavelet transformed,
providing the time localization of vibrational signals in the electronic
excited state. The photoexcited pyranine in aqueous solution is presented
as a case study. The transient and sequential activation of the simulated
vibrational signals is in good agreement with vibrational dynamics
obtained from femtosecond stimulated Raman spectroscopy data.
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Affiliation(s)
- Maria Gabriella Chiariello
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M. S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Greta Donati
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M. S. Angelo, via Cintia, I-80126 Napoli, Italy
| | - Nadia Rega
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M. S. Angelo, via Cintia, I-80126 Napoli, Italy.,CRIB Center for Advanced Biomaterials for Healthcare, Largo Barsanti e Matteucci, I-80125 Napoli, Italy
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24
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Krueger TD, Boulanger SA, Zhu L, Tang L, Fang C. Discovering a rotational barrier within a charge-transfer state of a photoexcited chromophore in solution. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:024901. [PMID: 32161777 PMCID: PMC7056454 DOI: 10.1063/1.5143441] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 02/18/2020] [Indexed: 05/15/2023]
Abstract
Methylation occurs in a myriad of systems with protective and regulatory functions. 8-methoxypyrene-1,3,6-trisulfonate (MPTS), a methoxy derivative of a photoacid, serves as a model system to study effects of methylation on the excited state potential energy landscape. A suite of spectroscopic techniques including transient absorption, wavelength-tunable femtosecond stimulated Raman spectroscopy (FSRS), and fluorescence quantum yield measurements via steady-state electronic spectroscopy reveal the energy dissipation pathways of MPTS following photoexcitation. Various solvents enable a systematic characterization of the H-bonding interaction, viscosity, and dynamic solvation that influence the ensuing relaxation pathways. The formation of a charge-transfer state out of the Franck-Condon region occurs on the femtosecond-to-picosecond solvation timescale before encountering a rotational barrier. The rotational relaxation correlates with the H-bond donating strength of solvent, while the rotational time constant lengthens as solvent viscosity increases. Time-resolved excited-state FSRS, aided by quantum calculations, provides crucial structural dynamics knowledge and reveals the sulfonate groups playing a dominant role during solvation. Several prominent vibrational motions of the pyrene ring backbone help maneuver the population toward the more fluorescent state. These ultrafast correlated electronic and nuclear motions ultimately govern the fate of the photoexcited chromophore in solution. Overall, MPTS in water displays the highest probability to fluoresce, while the aprotic and more viscous dimethyl sulfoxide enhances the nonradiative pathways. These mechanistic insights may apply robustly to other photoexcited chromophores that do not undergo excited-state proton transfer or remain trapped in a broad electronic state and also provide design principles to control molecular optical responses with site-specific atomic substitution.
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Affiliation(s)
- Taylor D. Krueger
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA
| | - Sean A. Boulanger
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA
| | - Liangdong Zhu
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA
| | - Longteng Tang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, USA
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25
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Fang C, Tang L. Mapping Structural Dynamics of Proteins with Femtosecond Stimulated Raman Spectroscopy. Annu Rev Phys Chem 2020; 71:239-265. [PMID: 32075503 DOI: 10.1146/annurev-physchem-071119-040154] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The structure-function relationships of biomolecules have captured the interest and imagination of the scientific community and general public since the field of structural biology emerged to enable the molecular understanding of life processes. Proteins that play numerous functional roles in cellular processes have remained in the forefront of research, inspiring new characterization techniques. In this review, we present key theoretical concepts and recent experimental strategies using femtosecond stimulated Raman spectroscopy (FSRS) to map the structural dynamics of proteins, highlighting the flexible chromophores on ultrafast timescales. In particular, wavelength-tunable FSRS exploits dynamic resonance conditions to track transient-species-dependent vibrational motions, enabling rational design to alter functions. Various ways of capturing excited-state chromophore structural snapshots in the time and/or frequency domains are discussed. Continuous development of experimental methodologies, synergistic correlation with theoretical modeling, and the expansion to other nonequilibrium, photoswitchable, and controllable protein systems will greatly advance the chemical, physical, and biological sciences.
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Affiliation(s)
- Chong Fang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA;
| | - Longteng Tang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA;
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26
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Fang C, Tang L, Chen C. Unveiling coupled electronic and vibrational motions of chromophores in condensed phases. J Chem Phys 2019; 151:200901. [PMID: 31779327 DOI: 10.1063/1.5128388] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The quest for capturing molecular movies of functional systems has motivated scientists and engineers for decades. A fundamental understanding of electronic and nuclear motions, two principal components of the molecular Schrödinger equation, has the potential to enable the de novo rational design for targeted functionalities of molecular machines. We discuss the development and application of a relatively new structural dynamics technique, femtosecond stimulated Raman spectroscopy with broadly tunable laser pulses from the UV to near-IR region, in tracking the coupled electronic and vibrational motions of organic chromophores in solution and protein environments. Such light-sensitive moieties hold broad interest and significance in gaining fundamental knowledge about the intramolecular and intermolecular Hamiltonian and developing effective strategies to control macroscopic properties. Inspired by recent experimental and theoretical advances, we focus on the in situ characterization and spectroscopy-guided tuning of photoacidity, excited state proton transfer pathways, emission color, and internal conversion via a conical intersection.
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Affiliation(s)
- Chong Fang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Longteng Tang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Cheng Chen
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
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27
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Taylor MA, Zhu L, Rozanov ND, Stout KT, Chen C, Fang C. Delayed vibrational modulation of the solvated GFP chromophore into a conical intersection. Phys Chem Chem Phys 2019; 21:9728-9739. [PMID: 31032505 DOI: 10.1039/c9cp01077g] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Green fluorescent protein (GFP) has revolutionized bioimaging and life sciences. Its successes have inspired modification of the chromophore structure and environment to tune emission properties, but outside the protein cage, the chromophore is essentially non-fluorescent. In this study, we employ the tunable femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption (TA) to map the energy dissipation pathways of GFP model chromophore (HBDI) in basic aqueous solution. Strategic tuning of the Raman pump to 550 nm exploits the stimulated emission band to enhance excited state vibrational motions as HBDI navigates the non-equilibrium potential energy landscape to pass through a conical intersection. The time-resolved FSRS uncovers prominent anharmonic couplings between a global out-of-plane bending mode of ∼227 cm-1 and two modes at ∼866 and 1572 cm-1 before HBDI reaches the twisted intramolecular charge transfer (TICT) state on the ∼3 ps time scale. Remarkably, the wavelet transform analysis reveals a ∼500 fs delayed onset of the coupling peaks, in correlation with the emergence of an intermediate charge-separated state en route to the TICT state. This mechanism is corroborated by the altered coupling matrix for the HBDI Raman modes in the 50% (v/v) water-glycerol mixture, and a notable lengthening of the picosecond time constant. The real-time molecular "movie" of the general rotor-like HBDI isomerization reaction following photoexcitation represents a significant advance in comprehending the photochemical reaction pathways of the solvated GFP chromophore, therefore providing a crucial foundation to enable rational design of diverse nanomachines from efficient molecular rotors to bright fluorescent probes.
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Affiliation(s)
- Miles A Taylor
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, USA.
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28
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Chen C, Zhu L, Baranov MS, Tang L, Baleeva NS, Smirnov AY, Yampolsky IV, Solntsev KM, Fang C. Photoinduced Proton Transfer of GFP-Inspired Fluorescent Superphotoacids: Principles and Design. J Phys Chem B 2019; 123:3804-3821. [DOI: 10.1021/acs.jpcb.9b03201] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Liangdong Zhu
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Mikhail S. Baranov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow 117997, Russia
- Pirogov Russian National Research Medical University, Ostrovitianov 1, Moscow 117997, Russia
| | - Longteng Tang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Nadezhda S. Baleeva
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow 117997, Russia
| | - Alexander Yu. Smirnov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow 117997, Russia
| | - Ilia V. Yampolsky
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow 117997, Russia
- Pirogov Russian National Research Medical University, Ostrovitianov 1, Moscow 117997, Russia
| | - Kyril M. Solntsev
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
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29
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Tang L, Zhu L, Wang Y, Fang C. Uncovering the Hidden Excited State toward Fluorescence of an Intracellular pH Indicator. J Phys Chem Lett 2018; 9:4969-4975. [PMID: 30111103 DOI: 10.1021/acs.jpclett.8b02281] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Intracellular pH (pHi) imaging is of paramount importance for life sciences. In this work, we implement the ultrafast electronic and stimulated Raman spectroscopies to unravel the fluorescence mechanism of an excitation-ratiometric pHi indicator in basic aqueous solution. After photoexcitation of the pHi indicator HPTS, a hidden charge-transfer (CT) state following the locally excited (LE) state is uncovered as an essential step prior to fluorescence and this LE → CT transition is gated by ultrafast solvation dynamics. A 835 cm-1 intermolecular vibrational mode is identified to potentially facilitate the CT-state formation on the 700 fs time scale. Dynamic correlation with the other excited-state Raman marker bands suggests that the transition between transient electronic states is aided by solvation events mostly in the molecular plane of HPTS. These vivid structural dynamics insights can enable the rational design of more efficient and bright pHi indicators in an H-bonding environment with controllable properties.
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Affiliation(s)
- Longteng Tang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Liangdong Zhu
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Yanli Wang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Chong Fang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
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30
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Excited State Structural Evolution of a GFP Single-Site Mutant Tracked by Tunable Femtosecond-Stimulated Raman Spectroscopy. Molecules 2018; 23:molecules23092226. [PMID: 30200474 PMCID: PMC6225354 DOI: 10.3390/molecules23092226] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 08/29/2018] [Accepted: 08/31/2018] [Indexed: 12/31/2022] Open
Abstract
Tracking vibrational motions during a photochemical or photophysical process has gained momentum, due to its sensitivity to the progression of reaction and change of environment. In this work, we implemented an advanced ultrafast vibrational technique, femtosecond-stimulated Raman spectroscopy (FSRS), to monitor the excited state structural evolution of an engineered green fluorescent protein (GFP) single-site mutant S205V. This mutation alters the original excited state proton transfer (ESPT) chain. By strategically tuning the Raman pump to different wavelengths (i.e., 801, 539, and 504 nm) to achieve pre-resonance with transient excited state electronic bands, the characteristic Raman modes of the excited protonated (A*) chromophore species and intermediate deprotonated (I*) species can be selectively monitored. The inhomogeneous distribution/population of A* species go through ESPT with a similar ~300 ps time constant, confirming that bridging a water molecule to protein residue T203 in the ESPT chain is the rate-limiting step. Some A* species undergo vibrational cooling through high-frequency motions on the ~190 ps time scale. At early times, a portion of the largely protonated A* species could also undergo vibrational cooling or return to the ground state with a ~80 ps time constant. On the photoproduct side, a ~1330 cm−1 delocalized motion is observed, with dispersive line shapes in both the Stokes and anti-Stokes FSRS with a pre-resonance Raman pump, which indicates strong vibronic coupling, as the mode could facilitate the I* species to reach a relatively stable state (e.g., the main fluorescent state) after conversion from A*. Our findings disentangle the contributions of various vibrational motions active during the ESPT reaction, and offer new structural dynamics insights into the fluorescence mechanisms of engineered GFPs and other analogous autofluorescent proteins.
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31
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Chen C, Zhu LD, Fang C. Femtosecond stimulated Raman line shapes: Dependence on resonance conditions of pump and probe pulses. CHINESE J CHEM PHYS 2018. [DOI: 10.1063/1674-0068/31/cjcp1805125] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
| | - Liang-dong Zhu
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
- Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon, 97331-6507, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
- Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon, 97331-6507, USA
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32
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Kayal S, Roy K, Lakshmanna YA, Umapathy S. Probing the effect of solvation on photoexcited 2-(2′-hydroxyphenyl)benzothiazole via ultrafast Raman loss spectroscopic studies. J Chem Phys 2018; 149:044310. [DOI: 10.1063/1.5028274] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Surajit Kayal
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
| | - Khokan Roy
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
| | - Y. Adithya Lakshmanna
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
| | - Siva Umapathy
- Inorganic and Physical Chemistry Department, Indian Institute of Science, Bangalore 560012, India
- Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012, India
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33
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Fang C, Tang L, Oscar BG, Chen C. Capturing Structural Snapshots during Photochemical Reactions with Ultrafast Raman Spectroscopy: From Materials Transformation to Biosensor Responses. J Phys Chem Lett 2018; 9:3253-3263. [PMID: 29799757 DOI: 10.1021/acs.jpclett.8b00373] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chemistry studies the composition, structure, properties, and transformation of matter. A mechanistic understanding of the pertinent processes is required to translate fundamental knowledge into practical applications. The current development of ultrafast Raman as a powerful time-resolved vibrational technique, particularly femtosecond stimulated Raman spectroscopy (FSRS), has shed light on the structure-energy-function relationships of various photosensitive systems. This Perspective reviews recent work incorporating optical innovations, including the broad-band up-converted multicolor array (BUMA) into a tunable FSRS setup, and demonstrates its resolving power to watch metal speciation and photolysis, leading to high-quality thin films, and fluorescence modulation of chimeric protein biosensors for calcium ion imaging. We discuss advantages of performing FSRS in the mixed time-frequency domain and present strategies to delineate mechanisms by tracking low-frequency modes and systematically modifying chemical structures with specific functional groups. These unique insights at the chemical-bond level have started to enable the rational design and precise control of functional molecular machines in optical, materials, energy, and life sciences.
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Affiliation(s)
- Chong Fang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331 , United States
| | - Longteng Tang
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331 , United States
| | - Breland G Oscar
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331 , United States
| | - Cheng Chen
- Department of Chemistry , Oregon State University , 153 Gilbert Hall , Corvallis , Oregon 97331 , United States
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34
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Tang L, Wang Y, Zhu L, Lee C, Fang C. Correlated Molecular Structural Motions for Photoprotection after Deep-UV Irradiation. J Phys Chem Lett 2018; 9:2311-2319. [PMID: 29672054 DOI: 10.1021/acs.jpclett.8b00999] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Exposure to ultraviolet (UV) light could cause photodamage to biomolecular systems and degrade optoelectronic devices. To mitigate such detrimental effects from the bottom up, we strategically select a photosensitive molecule pyranine and implement femtosecond electronic and Raman spectroscopies to elucidate its ultrafast photoprotection mechanisms in solution. Our results show that pyranine undergoes excited-state proton transfer in water, while this process is blocked in methanol regardless of excitation wavelengths (267, 400 nm). After 267 nm irradiation, the molecule relaxes from a higher lying electronic state into a lower lying singlet state with a <300 fs time constant, followed by solvation events. Transient Raman marker bands exhibit different patterns of intensity dynamics and frequency shift that elucidate the real-time interplay among conformational motions, photochemical reaction, and vibrational cooling after excitation. More energetic photons are revealed to selectively enhance certain relaxation pathways. These mechanistic findings offer new guidelines to improve the UV tolerance and stability of the engineered functional molecules in materials and life sciences.
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Affiliation(s)
- Longteng Tang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Yanli Wang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Liangdong Zhu
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Che Lee
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Chong Fang
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
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35
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Louant O, Champagne B, Liégeois V. Investigation of the Electronic Excited-State Equilibrium Geometries of Three Molecules Undergoing ESIPT: A RI-CC2 and TDDFT Study. J Phys Chem A 2018; 122:972-984. [DOI: 10.1021/acs.jpca.7b10881] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Orian Louant
- Laboratoire de Chimie Théorique,
UCPTS, Namur Institute of Structured Matter, Université de Namur, rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Benoît Champagne
- Laboratoire de Chimie Théorique,
UCPTS, Namur Institute of Structured Matter, Université de Namur, rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Vincent Liégeois
- Laboratoire de Chimie Théorique,
UCPTS, Namur Institute of Structured Matter, Université de Namur, rue de Bruxelles 61, B-5000 Namur, Belgium
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36
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Chen C, Liu W, Baranov MS, Baleeva NS, Yampolsky IV, Zhu L, Wang Y, Shamir A, Solntsev KM, Fang C. Unveiling Structural Motions of a Highly Fluorescent Superphotoacid by Locking and Fluorinating the GFP Chromophore in Solution. J Phys Chem Lett 2017; 8:5921-5928. [PMID: 29148819 DOI: 10.1021/acs.jpclett.7b02661] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Superphotoacidity involves ultrafast proton motions implicated in numerous chemical and biological processes. We used conformational locking and strategic addition of electron-withdrawing substituents to synthesize a new GFP chromophore analogue: p-HO-3,5-diF-BDI:BF2 (diF). It is highly fluorescent and exhibits excited-state proton transfer (ESPT) in various solvents, placing it among the strongest photoacids. Tunable femtosecond stimulated Raman spectroscopy with unique resonance conditions and transient absorption are complementarily employed to elucidate the structural basis for superphotoacidity. We reveal a multistep ESPT reaction from diF to methanol with an initial proton dissociation on the ∼600 fs time scale that forms a charge-separated state, stabilized by solvation, and followed by a diffusion-controlled proton transfer on the ∼350 ps time scale. A ∼1580 cm-1 phenolic ring motion is uncovered to accompany ESPT before 1 ps. This study provides a vivid movie of the photoinduced proton dissociation of a superphotoacid with bright fluorescence, effectively bridging fundamental mechanistic insights to precise control of macroscopic functions.
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Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University , 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Weimin Liu
- Department of Chemistry, Oregon State University , 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Mikhail S Baranov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences , Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Nadezhda S Baleeva
- Institute of Bioorganic Chemistry, Russian Academy of Sciences , Miklukho-Maklaya 16/10, 117997 Moscow, Russia
| | - Ilia V Yampolsky
- Institute of Bioorganic Chemistry, Russian Academy of Sciences , Miklukho-Maklaya 16/10, 117997 Moscow, Russia
- Pirogov Russian National Research Medical University , Ostrovitianov 1, Moscow 117997, Russia
| | - Liangdong Zhu
- Department of Chemistry, Oregon State University , 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Yanli Wang
- Department of Chemistry, Oregon State University , 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Alexandra Shamir
- School of Chemistry and Biochemistry, Georgia Institute of Technology , 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Kyril M Solntsev
- School of Chemistry and Biochemistry, Georgia Institute of Technology , 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Chong Fang
- Department of Chemistry, Oregon State University , 153 Gilbert Hall, Corvallis, Oregon 97331, United States
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37
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Awasthi AA, Singh PK. Excited-State Proton Transfer on the Surface of a Therapeutic Protein, Protamine. J Phys Chem B 2017; 121:10306-10317. [PMID: 29032681 DOI: 10.1021/acs.jpcb.7b07151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Proton transfer reactions on biosurfaces play an important role in a myriad of biological processes. Herein, the excited-state proton transfer reaction of 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) has been investigated in the presence of an important therapeutic protein, Protamine (PrS), using ground-state absorption, steady-state, and detailed time-resolved emission measurements. HPTS forms a 1:1 complex with Protamine with a high association constant of 2.6 × 104 M-1. The binding of HPTS with Protamine leads to a significant modulation in the ground-state prototropic equilibrium causing a downward shift of 1.1 unit in the acidity constant (pKa). In contrast to a large number of reports of slow proton transfer of HPTS on biosurfaces, interestingly, HPTS registers a faster proton transfer event in the presence of Protamine as compared to that of even the bulk aqueous buffer medium. Furthermore, the dimensionality of the proton diffusion process is also significantly reduced on the surface of Protamine that is in contrast to the behavior of HPTS in the bulk aqueous buffer medium, where the proton diffusion process is three-dimensional. The effect of ionic strength on the binding of HPTS toward PrS suggests a predominant role of electrostatic interaction between anionic HPTS and cationic Protamine, which is further supported by molecular docking simulations which predict that the most preferable binding site for HPTS on the surface of Protamine is surrounded by multiple cationic arginine residues.
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Affiliation(s)
| | - Prabhat K Singh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre , Mumbai 400085, India.,Homi Bhabha National Institute , Training School Complex, Anushaktinagar, Mumbai 400094, India
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38
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Alarcos N, Cohen B, Ziółek M, Douhal A. Photochemistry and Photophysics in Silica-Based Materials: Ultrafast and Single Molecule Spectroscopy Observation. Chem Rev 2017; 117:13639-13720. [PMID: 29068670 DOI: 10.1021/acs.chemrev.7b00422] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Silica-based materials (SBMs) are widely used in catalysis, photonics, and drug delivery. Their pores and cavities act as hosts of diverse guests ranging from classical dyes to drugs and quantum dots, allowing changes in the photochemical behavior of the confined guests. The heterogeneity of the guest populations as well as the confinement provided by these hosts affect the behavior of the formed hybrid materials. As a consequence, the observed reaction dynamics becomes significantly different and complex. Studying their photobehavior requires advanced laser-based spectroscopy and microscopy techniques as well as computational methods. Thanks to the development of ultrafast (spectroscopy and imaging) tools, we are witnessing an increasing interest of the scientific community to explore the intimate photobehavior of these composites. Here, we review the recent theoretical and ultrafast experimental studies of their photodynamics and discuss the results in comparison to those in homogeneous media. The discussion of the confined dynamics includes solvation and intra- and intermolecular proton-, electron-, and energy transfer events of the guest within the SBMs. Several examples of applications in photocatalysis, (photo)sensors, photonics, photovoltaics, and drug delivery demonstrate the vast potential of the SBMs in modern science and technology.
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Affiliation(s)
- Noemí Alarcos
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Boiko Cohen
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
| | - Marcin Ziółek
- Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University , Umultowska 85, 61-614 Poznań, Poland
| | - Abderrazzak Douhal
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha , Avenida Carlos III, S.N., 45071 Toledo, Spain
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Kowalewski M, Fingerhut BP, Dorfman KE, Bennett K, Mukamel S. Simulating Coherent Multidimensional Spectroscopy of Nonadiabatic Molecular Processes: From the Infrared to the X-ray Regime. Chem Rev 2017; 117:12165-12226. [DOI: 10.1021/acs.chemrev.7b00081] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Markus Kowalewski
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Benjamin P. Fingerhut
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - Konstantin E. Dorfman
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Kochise Bennett
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
| | - Shaul Mukamel
- Department
of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697-2025, United States
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Oscar BG, Chen C, Liu W, Zhu L, Fang C. Dynamic Raman Line Shapes on an Evolving Excited-State Landscape: Insights from Tunable Femtosecond Stimulated Raman Spectroscopy. J Phys Chem A 2017; 121:5428-5441. [DOI: 10.1021/acs.jpca.7b04404] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Breland G. Oscar
- Department
of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Cheng Chen
- Department
of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Weimin Liu
- Department
of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Liangdong Zhu
- Department
of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331, United States
| | - Chong Fang
- Department
of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
- Department
of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331, United States
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41
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Tang L, Wang Y, Liu W, Zhao Y, Campbell RE, Fang C. Illuminating Photochemistry of an Excitation Ratiometric Fluorescent Protein Calcium Biosensor. J Phys Chem B 2017; 121:3016-3023. [PMID: 28326779 DOI: 10.1021/acs.jpcb.7b01269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Fluorescent protein (FP)-based biosensors have become an important and promising tool to track metal ion movement inside living systems. Their working principles after light irradiation, however, remain elusive. To facilitate the rational design of biosensors, we dissect the fluorescence modulation mechanism of a newly developed excitation ratiometric green FP-based Ca2+ biosensor, GEX-GECO1, using femtosecond stimulated Raman spectroscopy (FSRS) in the electronic excited state. Upon 400 nm photoexcitation, characteristic vibrational marker bands at ∼1180 and 1300 cm-1 show concomitant decay and rise dynamics, probing the progression of an ultrafast excited state proton transfer (ESPT) reaction. The Ca2+-bound biosensor exhibits two distinct populations that undergo ESPT with ∼6 and 80 ps time constants, in contrast to one dominant population with a 25 ps time constant in the Ca2+-free biosensor. This result is supported by key structural constraints from molecular dynamics simulations with and without Ca2+. The blueshift of the ∼1265 cm-1 C-O stretch mode unravels the vibrational cooling dynamics of the protonated chromophore regardless of Ca2+ binding events. This unique line of inquiry reveals the essential structural dynamics basis of fluorescence modulation inside an excitation ratiometric protein biosensor, correlating the uncovered chromophore structural heterogeneity with different H-bonding configurations and intrinsic proton transfer rate in the photoexcited state.
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Affiliation(s)
- Longteng Tang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Yanli Wang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Weimin Liu
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Yongxin Zhao
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Robert E Campbell
- Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | - Chong Fang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
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42
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Liu W, Tang L, Oscar BG, Wang Y, Chen C, Fang C. Tracking Ultrafast Vibrational Cooling during Excited-State Proton Transfer Reaction with Anti-Stokes and Stokes Femtosecond Stimulated Raman Spectroscopy. J Phys Chem Lett 2017; 8:997-1003. [PMID: 28195486 DOI: 10.1021/acs.jpclett.7b00322] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Energy dissipation following photoexcitation is foundational to photophysics and chemistry. Consequently, understanding such processes on molecular time scales holds paramount importance. Femtosecond stimulated Raman spectroscopy (FSRS) has been used to study the molecular structure-function relationships but usually on the Stokes side. Here, we perform both Stokes and anti-Stokes FSRS to track energy dissipation and excited-state proton transfer (ESPT) for the photoacid pyranine in aqueous solution. We reveal biphasic vibrational cooling on fs-ps time scales during ESPT. Characteristic low-frequency motions (<800 cm-1) exhibit initial energy dissipation (∼2 ps) that correlates with functional events of forming contact ion pairs via H-bonds between photoacid and water, which lengthens to ∼9 ps in methanol where ESPT is inhibited. The interplay between photoinduced dissipative and reactive channels is implied. Thermal cooling to bulk solvent occurs on the ∼50 ps time scale. These results demonstrate the combined Stokes and anti-Stokes FSRS as a powerful toolset to elucidate structural dynamics.
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Affiliation(s)
- Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University , Pudong, Shanghai 201210, People's Republic of China
| | - Longteng Tang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Breland G Oscar
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Yanli Wang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Cheng Chen
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
| | - Chong Fang
- Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States
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Xie Y, Ilic S, Skaro S, Maslak V, Glusac KD. Excited-State Hydroxide Ion Release From a Series of Acridinol Photobases. J Phys Chem A 2017; 121:448-457. [DOI: 10.1021/acs.jpca.6b10980] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Yun Xie
- Department
of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Stefan Ilic
- Department
of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Sanja Skaro
- Faculty
of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia
| | - Veselin Maslak
- Faculty
of Chemistry, University of Belgrade, Studentski Trg 12-16, Belgrade 11000, Serbia
| | - Ksenija D. Glusac
- Department
of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, United States
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Tachibana SR, Tang L, Wang Y, Zhu L, Liu W, Fang C. Tuning calcium biosensors with a single-site mutation: structural dynamics insights from femtosecond Raman spectroscopy. Phys Chem Chem Phys 2017; 19:7138-7146. [DOI: 10.1039/c6cp08821j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Structural dynamics governing the emission properties of a single-site mutant of fluorescent-protein-based calcium biosensors are elucidated by femtosecond stimulated Raman spectroscopy.
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Affiliation(s)
- Sean R. Tachibana
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
| | - Longteng Tang
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
| | - Yanli Wang
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
| | - Liangdong Zhu
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
| | - Weimin Liu
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
| | - Chong Fang
- Oregon State University
- Department of Chemistry
- 263 Linus Pauling Science Centre (lab)
- Corvallis
- USA
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Heo W, Uddin N, Park JW, Rhee YM, Choi CH, Joo T. Coherent intermolecular proton transfer in the acid–base reaction of excited state pyranine. Phys Chem Chem Phys 2017; 19:18243-18251. [DOI: 10.1039/c7cp01944k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The acidic proton in pyranine is transferred coherently to acetate through the stretching motion of the whole molecule.
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Affiliation(s)
- Wooseok Heo
- Department of Chemistry
- Pohang University of Science and Technology (POSTECH)
- Pohang 37673
- South Korea
| | - Nizam Uddin
- Department of Chemistry
- Kyunpook National University
- Daegu 41566
- South Korea
| | - Jae Woo Park
- Department of Chemistry
- Pohang University of Science and Technology (POSTECH)
- Pohang 37673
- South Korea
| | - Young Min Rhee
- Department of Chemistry
- Pohang University of Science and Technology (POSTECH)
- Pohang 37673
- South Korea
| | - Cheol Ho Choi
- Department of Chemistry
- Kyunpook National University
- Daegu 41566
- South Korea
| | - Taiha Joo
- Department of Chemistry
- Pohang University of Science and Technology (POSTECH)
- Pohang 37673
- South Korea
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46
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Zhu L, Saha S, Wang Y, Keszler DA, Fang C. Monitoring Photochemical Reaction Pathways of Tungsten Hexacarbonyl in Solution from Femtoseconds to Minutes. J Phys Chem B 2016; 120:13161-13168. [DOI: 10.1021/acs.jpcb.6b11773] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liangdong Zhu
- Department
of Chemistry and Center for Sustainable Materials Chemistry (CSMC), Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, United States
- Department
of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331-6507, United States
| | - Sumit Saha
- Department
of Chemistry and Center for Sustainable Materials Chemistry (CSMC), Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, United States
| | - Yanli Wang
- Department
of Chemistry and Center for Sustainable Materials Chemistry (CSMC), Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, United States
| | - Douglas A. Keszler
- Department
of Chemistry and Center for Sustainable Materials Chemistry (CSMC), Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, United States
- Department
of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331-6507, United States
| | - Chong Fang
- Department
of Chemistry and Center for Sustainable Materials Chemistry (CSMC), Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331-4003, United States
- Department
of Physics, Oregon State University, 301 Weniger Hall, Corvallis, Oregon 97331-6507, United States
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47
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Shen H, Zhang Y, Yan TM, Wang Z, Jiang Y. Moderately strong pump-induced ultrafast dynamics in solution. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2016.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Alarcos N, Cohen B, Douhal A. A slowing down of proton motion from HPTS to water adsorbed on the MCM-41 surface. Phys Chem Chem Phys 2016; 18:2658-71. [PMID: 26705542 DOI: 10.1039/c5cp04548g] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We report on the steady-state and femtosecond-nanosecond (fs-ns) behaviour of 8-hydroxypyrene-1,3,6-trisulfonate (pyranine, HPTS) and its interaction with mesoporous silica based materials (MCM-41) in both solid-state and dichloromethane (DCM) suspensions in the absence and presence of water. In the absence of water, HPTS forms aggregates which are characterized by a broad emission spectrum and multiexponential behavior (τsolid-state/DCM = 120 ps, 600 ps, 2.2 ns). Upon interaction with MCM41, the aggregate population is found to be lower, leading to the formation of adsorbed monomers. In the presence of water (1%), HPTS with and without MCM41 materials in DCM suspensions undergoes an excited-state intermolecular proton-transfer (ESPT) reaction in the protonated form (ROH*) producing a deprotonated species (RO(-)*). The long-time emission decays of the ROH* in different systems in the presence of water are multiexponential, and are analysed using the diffusion-assisted geminate recombination model. The obtained proton-transfer and recombination rate constants for HPTS and HPTS/MCM41 complexes in DCM suspensions in the presence of water are kPT = 13 ns(-1), krec = 7.5 Å ns(-1), and kPT = 5.4 ns(-1), krec = 2.2 Å ns(-1), respectively, The slowing down of both processes in the latter case is explained in terms of specific interactions of the dye and of the water molecules with the silica surface. The ultrafast dynamics (fs-regime) of the HPTS/MCM41 complexes in DCM suspensions, without and with water, shows two components which are assigned to intramolecular vibrational-energy relaxation (IVR) (∼120 fs vs. ∼0.8 ps), and vibrational relaxation/cooling (VC), and charge transfer (CT) processes (∼2 ps without water and ∼5 ps with water) of the adsorbed ROH*. Our results provide new knowledge on the interactions and the proton-transfer reaction dynamics of HPTS adsorbed on mesoporous materials.
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Affiliation(s)
- Noemí Alarcos
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
| | - Boiko Cohen
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
| | - Abderrazzak Douhal
- Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
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Liu W, Wang Y, Tang L, Oscar BG, Zhu L, Fang C. Panoramic portrait of primary molecular events preceding excited state proton transfer in water. Chem Sci 2016; 7:5484-5494. [PMID: 30034688 PMCID: PMC6021748 DOI: 10.1039/c6sc00672h] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 05/11/2016] [Indexed: 12/31/2022] Open
Abstract
Primary events that power ultrafast excited state proton transfer in water are revealed to involve coupled intermolecular and intramolecular motions.
Photochemistry powers numerous processes from luminescence and human vision, to light harvesting. However, the elucidation of multidimensional photochemical reaction coordinates on molecular timescales remains challenging. We developed wavelength-tunable femtosecond stimulated Raman spectroscopy to simultaneously achieve pre-resonance enhancement for transient reactant and product species of the widely used photoacid pyranine undergoing excited-state proton transfer (ESPT) reaction in solution. In the low-frequency region, the 280 cm–1 ring deformation mode following 400 nm photoexcitation exhibits pronounced intensity oscillations on the sub-picosecond timescale due to anharmonic vibrational coupling to the 180 cm–1 hydrogen-bond stretching mode only in ESPT-capable solvents, indicating a primary event of functional relevance. This leads to the contact ion pair formation on the 3 ps timescale before diffusion-controlled separation. The intermolecular 180 cm–1 mode also reveals vibrational cooling time constants, ∼500 fs and 45 ps in both H2O and D2O, which differ from ESPT time constants of ∼3/8 and 90/250 ps in H2O/D2O, respectively. Spectral results using H218O further substantiate the functional role of the intermolecular 180 cm–1 mode in modulating the distance between proton donor and acceptor and forming the transient ion pair. The direct observation of molecular structural evolution across a wide spectral region during photochemical reactions enriches our fundamental understanding of potential energy surface and holds the key to advancing energy and biological sciences with exceptional atomic and temporal precision.
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Affiliation(s)
- Weimin Liu
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
| | - Yanli Wang
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
| | - Longteng Tang
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
| | - Breland G Oscar
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
| | - Liangdong Zhu
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
| | - Chong Fang
- Oregon State University , Department of Chemistry , 263 Linus Pauling Science Centre (lab) , 153 Gilbert Hall (office) , Corvallis , OR 97331 , USA . ; ; Tel: +1 541 737 6704
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