Excited-state dynamics of all-trans protonated retinal Schiff base in CRABPII-based rhodopsin mimics

Li, Gaoshang; Hu, Yongnan; Pei, Sizhu; Meng, Jiajia; Wang, Jiayu; Ju, Wang; Yue, Shuai; Wang, Zhuan; Wang, Shufeng; Liu, Xinfeng; Weng, Yuxiang; Peng, Xubiao; Zhao, Qing

doi:10.1016/j.bpj.2022.09.032

Cited by 4 publications

(6 citation statements)

References 51 publications

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“…In Figure 7b, we show the difference of the theoretically calculated terahertz absorption spectra between without and with retinal binding, which shows similar properties to Figure 7a although there is some detailed mismatch at round frequency 55 cm -1 . We note that the mutation A32W has been proven to have significant impacts on the UV/VS absorption spectra, where the absorption peak of R2 bound with retinal is significantly blue shifted relative to R1 [29] . In our current study, by comparing the terahertz absorption difference between the cases with and without retinal binding, we show that the mutation A32W also significantly affects the impacts of retinal binding in the absorption in the 30~70 cm -1 terahertz domain.…”

Section: : Comparison Of the Impact Of Retinal Binding On Thz Absorpt...mentioning

confidence: 84%

“…We note that the mutation A32W has been proven to have significant impacts on the UV/VS absorption spectra, where the absorption peak of R2 bound with retinal is significantly blue shifted relative to R1 [29] . In our current study, by comparing the terahertz absorption difference between the cases with and without retinal binding, we show that the mutation A32W also significantly affects the impacts of retinal binding in the absorption in the 30∼70 cm −1 terahertz domain.…”

Section: Resultsmentioning

confidence: 99%

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Influences of single mutation and retinal binding on the THz absorption spectra of CRABP-II based rhodopsin mimics

Wang,

Hu,

Meng

et al. 2024

Preprint

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The collective vibration of many biomolecules such as the skeleton vibration, dipole rotation and conformational bending falls in the terahertz (THz) frequency domain. Terahertz time-domain spectroscopy (THZ-TDS), which is very sensitive to the conformational changes, can be used to characterize the collective vibration of biomolecules. In this study, we investigated the low-frequency THz absorption spectra of two rhodopsin mimics using transmission THz-TDS. Using the normal model analysis (NMA), we successfully modelled the experimental terahertz absorption curve and attributed a unique collective motion pattern to each distinctive terahertz absorption frequency. By comparing the terahertz absorption spectra between without and with retinal, we show that the retinal binding can significantly alters the terahertz absorption spectra as well as the vibration modes. Furthermore, by comparing the terahertz absorption spectra between the two mutants, we observed that the single mutation can significantly change the influence of retinal binding on the terahertz absorption spectrum.

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Section: : Comparison Of the Impact Of Retinal Binding On Thz Absorpt...mentioning

confidence: 84%

Section: Resultsmentioning

confidence: 99%

Influences of single mutation and retinal binding on the THz absorption spectra of CRABP-II based rhodopsin mimics

Wang,

Hu,

Meng

et al. 2024

Preprint

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“…Samples were essentially prepared as described previously: 46 M1-121E full-length sequences were cloned in a pET-28a plasmid with an N-terminal His-tag and expressed in Escherichia coli cells. We used codon-optimized E. coli constructs to maximize the efficiency and yield for protein purification.…”

Section: Methodsmentioning

confidence: 99%

“…So far, several rhodopsin mimics have been designed based on CRABPII or CRBPII, [34][35][36][37][38][39][40][41][42] and their dynamics have been well investigated. [43][44][45][46] In these mimics, the chromophore retinal can covalently bond to the protein by forming a Schiff base (SB) with the Lys residue, which is essential for the photoreaction process. However, unlike the traditional natural rhodopsin that consists of seven transmembrane α-helices connected by extracellular and intracellular loops, these mimics are not membrane proteins but have β-barrel-like structures with only half the number of residues seen in natural rhodopsin.…”

Section: Introductionmentioning

confidence: 99%

Is M1-L121E a good mimic on microbial rhodopsin? A viewpoint from excited-state dynamics

Li,

Meng,

et al. 2023

Preprint

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Microbial rhodopsin, an important photoreceptor protein, has been widely used in several fields, such as optogenetics, biotechnology, and biodevicesetc. However, current microbial rhodopsins are all transmembrane proteins, which both complicates the investigation on the photoreaction mechanism and limits their further applications. Therefore, a suitable mimic for microbial rhodopsin can not only provide a better model for understanding the mechanism, but also can extend the applications. The human protein CRABPII turns out to be a good template for design mimics on rhodopsin, due to the convenience in synthesis and the stability after mutations. Recently, Geigeret al.designed a new CRABPII-based mimic M1-L121E on microbial rhodopsin with the correct 13-cis (13C) isomerization after irritation. However, it still remains a question how similar it is compared with the natural microbial rhodopsin, in particular in the aspect of the photoreaction dynamics. In this article, we investigated the excited-state dynamics of this mimic by measuring its transient absorption spectra. Our results reveal that there are two components in the solution of mimic M1-L121E at PH=8, known as protonated Schiff base (PSB) and unprotonated Schiff base (USB) states. In both states, the photoreaction process from 13-cis (13C) to all-trans (AT) is faster than that from the inverse direction. In addition, the photoreaction process in PSB state is faster than that in the USB state. In the end, we compared the isomerization time of the PSB state with the properties of the microbial rhodopsin, and confirmed that the mimic M1-L121E indeed captures the main feature of the rhodopsin and is a good model of microbial rhodopsin in the photoreaction dynamics. However, our results also reveal significant differences in the excited-state dynamics of the mimic relative to the natural microbial rhodopsin, including the slower PSB isomerization rates in both 13C-AT and AT-13C directions, as well as the unusual USB photoreaction dynamics at PH=8. Such unique properties have not been observed in the natural rhodopsin, which could further deepen the understanding in photoreaction mechanism of the photosensitive proteins.

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“…In these mimics, the chromophore retinal can covalently bond to the protein by forming a Schiff base (SB) with the Lys residue, which is essential for the photoreaction process. The dynamics of some mimics have been investigated experimentally or computationally, − where it is found that the isomerization usually happens in a time scale of picoseconds. However, unlike the traditional natural rhodopsin, which consists of seven transmembrane α-helices connected by extracellular and intracellular loops, these mimics are not membrane proteins but have β-barrel-like structures with only half the number of residues seen in the natural rhodopsin.…”

Section: Introductionmentioning

confidence: 99%

Excited-State Dynamics of a CRABPII-Based Microbial Rhodopsin Mimic

Li,

Meng,

et al. 2024

J. Phys. Chem. B

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Microbial rhodopsin, a pivotal photoreceptor protein, has garnered widespread application in diverse fields such as optogenetics, biotechnology, biodevices, etc. However, current microbial rhodopsins are all transmembrane proteins, which both complicates the investigation on the photoreaction mechanism and limits their further applications. Therefore, a specific mimic for microbial rhodopsin can not only provide a better model for understanding the mechanism but also can extend the applications. The human protein CRABPII turns out to be a good template for design mimics on rhodopsin due to the convenience in synthesis and the stability after mutations. Recently, Geiger et al. designed a new CRABPII-based mimic M1-L121E on microbial rhodopsin with the 13-cis, syn (13C) isomerization after irradiation. However, it still remains a question as to how similar it is compared with the natural microbial rhodopsin, in particular, in the aspect of the photoreaction dynamics. In this article, we investigate the excited-state dynamics of this mimic by measuring its transient absorption spectra. Our results reveal that there are two components in the solution of mimic M1-L121E at pH 8, known as protonated Schiff base (PSB) and unprotonated Schiff base (USB) states. In both states, the photoreaction process from 13-cis, syn(13C) to all-trans,anti (AT) is faster than that from the inverse direction. In addition, the photoreaction process in the PSB state is faster than that in the USB state. We compared the isomerization time of the PSB state to that of microbial rhodopsin. Our findings indicate that M1-L121E exhibits behaviors similar to those of microbial rhodopsins in the general pattern of PSB isomerization, where the isomerization from 13C to AT is much faster than its inverse direction. However, our results also reveal significant differences in the excited-state dynamics of the mimic relative to the native microbial rhodopsin, including the slower PSB isomerization rates as well as the unusual USB photoreaction dynamics at pH = 8. By elucidating the distinctive characteristics of mimics M1-L121E, this study enhances our understanding of microbial rhodopsin mimics and their potential applications.

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Excited-state dynamics of all-trans protonated retinal Schiff base in CRABPII-based rhodopsin mimics

Cited by 4 publications

References 51 publications

Influences of single mutation and retinal binding on the THz absorption spectra of CRABP-II based rhodopsin mimics

Influences of single mutation and retinal binding on the THz absorption spectra of CRABP-II based rhodopsin mimics

Is M1-L121E a good mimic on microbial rhodopsin? A viewpoint from excited-state dynamics

Excited-State Dynamics of a CRABPII-Based Microbial Rhodopsin Mimic

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