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Salvadori G, Mazzeo P, Accomasso D, Cupellini L, Mennucci B. Deciphering Photoreceptors Through Atomistic Modeling from Light Absorption to Conformational Response. J Mol Biol 2024; 436:168358. [PMID: 37944793 DOI: 10.1016/j.jmb.2023.168358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
In this review, we discuss the successes and challenges of the atomistic modeling of photoreceptors. Throughout our presentation, we integrate explanations of the primary methodological approaches, ranging from quantum mechanical descriptions to classical enhanced sampling methods, all while providing illustrative examples of their practical application to specific systems. To enhance the effectiveness of our analysis, our primary focus has been directed towards the examination of applications across three distinct photoreceptors. These include an example of Blue Light-Using Flavin (BLUF) domains, a bacteriophytochrome, and the orange carotenoid protein (OCP) employed by cyanobacteria for photoprotection. Particular emphasis will be placed on the pivotal role played by the protein matrix in fine-tuning the initial photochemical event within the embedded chromophore. Furthermore, we will investigate how this localized perturbation initiates a cascade of events propagating from the binding pocket throughout the entire protein structure, thanks to the intricate network of interactions between the chromophore and the protein.
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Affiliation(s)
- Giacomo Salvadori
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Patrizia Mazzeo
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Davide Accomasso
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Lorenzo Cupellini
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Benedetta Mennucci
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
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Zhou Y, Tang S, Chen Z, Zhou Z, Huang J, Kang XW, Zou S, Wang B, Zhang T, Ding B, Zhong D. Origin of the multi-phasic quenching dynamics in the BLUF domains across the species. Nat Commun 2024; 15:623. [PMID: 38245518 PMCID: PMC10799861 DOI: 10.1038/s41467-023-44565-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024] Open
Abstract
Blue light using flavin (BLUF) photoreceptors respond to light via one of nature's smallest photo-switching domains. Upon photo-activation, the flavin cofactor in the BLUF domain exhibits multi-phasic dynamics, quenched by a proton-coupled electron transfer reaction involving the conserved Tyr and Gln. The dynamic behavior varies drastically across different species, the origin of which remains controversial. Here, we incorporate site-specific fluorinated Trp into three BLUF proteins, i.e., AppA, OaPAC and SyPixD, and characterize the percentages for the Wout, WinNHin and WinNHout conformations using 19F nuclear magnetic resonance spectroscopy. Using femtosecond spectroscopy, we identify that one key WinNHin conformation can introduce a branching one-step proton transfer in AppA and a two-step proton transfer in OaPAC and SyPixD. Correlating the flavin quenching dynamics with the active-site structural heterogeneity, we conclude that the quenching rate is determined by the percentage of WinNHin, which encodes a Tyr-Gln configuration that is not conducive to proton transfer.
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Affiliation(s)
- Yalin Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Siwei Tang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zijing Chen
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhongneng Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiulong Huang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shuhua Zou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bingyao Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tianyi Zhang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.
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Buhrke D, Lahav Y, Rao A, Ruf J, Schapiro I, Hamm P. Transient 2D IR Spectroscopy and Multiscale Simulations Reveal Vibrational Couplings in the Cyanobacteriochrome Slr1393-g3. J Am Chem Soc 2023. [PMID: 37450891 DOI: 10.1021/jacs.3c00896] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Cyanobacteriochromes are bistable photoreceptor proteins with desirable photochemical properties for biotechnological applications, such as optogenetics or fluorescence microscopy. Here, we investigate Slr1393-g3, a cyanobacteriochrome that reversibly photoswitches between a red-absorbing (Pr) and green-absorbing (Pg) form. We applied advanced IR spectroscopic methods to track the sequence of intermediates during the photocycle over many orders of magnitude in time. In the conversion from Pg to Pr, we have revealed a new intermediate with distinct spectroscopic features in the IR, which precedes Pr formation using transient IR spectroscopy. In addition, stationary and transient 2D IR experiments measured the vibrational couplings between different groups of the chromophore and the protein in these intermediate states, as well as their structural disorder. Anharmonic QM/MM calculations predict spectra in good agreement with experimental 2D IR spectra of the initial and final states of the photocycle. They facilitate the assignment of the IR spectra that serve as a basis for the interpretation of the spectroscopic results and suggest structural changes of the intermediates along the photocycle.
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Affiliation(s)
- David Buhrke
- Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
- Institute of Biology, Humboldt University Berlin, 10115 Berlin, Germany
| | - Yigal Lahav
- Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
- MIGAL - Galilee Research Institute, 1101602 Kiryat Shmona, Israel
| | - Aditya Rao
- Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Jeannette Ruf
- Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Peter Hamm
- Department of Chemistry, University of Zurich, 8057 Zurich, Switzerland
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Hildebrandt P. Vibrational Spectroscopy of Phytochromes. Biomolecules 2023; 13:1007. [PMID: 37371587 DOI: 10.3390/biom13061007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Phytochromes are biological photoswitches that translate light into physiological functions. Spectroscopic techniques are essential tools for molecular research into these photoreceptors. This review is directed at summarizing how resonance Raman and IR spectroscopy contributed to an understanding of the structure, dynamics, and reaction mechanism of phytochromes, outlining the substantial experimental and theoretical challenges and describing the strategies to master them. It is shown that the potential of the various vibrational spectroscopic techniques can be most efficiently exploited using integral approaches via a combination of theoretical methods as well as other experimental techniques.
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Affiliation(s)
- Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
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