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Yasushi Imamoto - One of the best experts on this subject based on the ideXlab platform.

  • 2003. Comparison of the photochemical reaction of Photoactive Yellow Protein in crystal with reaction in solution
    2020
    Co-Authors: Eriko Mano, Yasushi Imamoto, Hironari Kamikubo, Mikio Kataoka
    Abstract:

    Abstract. Photoactive Yellow Protein (PYP) is a photoreceptor Protein for the negative phototaxis of Ectothiorhodospira halophila. The crystal structures of several photo-intermediates have been revealed by X-ray crystallography. In the crystal structure of the active intermediate, PYPM, no significant structural changes were observed except for the vicinity of the chromophore. On the contrary, spectroscopic studies with solution condition demonstrated that global structural changes occur during the photo-cycle. In order to reveal the origin of the discrepancies, we measured the reaction kinetics upon illumination under crystal condition and to compare them with those observed under solution condition. The reactive portion decreases with the increase of crystallinity. The rate constant of PYPM decay also decreases with the increase of crystallinity. These results suggest two possibilities: (1) PYP in crystal does not react by the illumination; (2) the photoreaction rate is highly accelerated in crystal. Consequently, the photoreaction in crystal is considered to be highly influenced by the force constraint from crystalline lattice. Abbreviations PYP, Photoactive Yellow Protein from Ectothiorhodospira halophila; MES, 2-(N-morpholino) ethanesulfonic acid; FTIR, Fourier transform infrared, Rg, radius of gyration

  • ultrafast carbonyl motion of the Photoactive Yellow Protein chromophore probed by femtosecond circular dichroism
    Journal of the American Chemical Society, 2013
    Co-Authors: Lucille Mendonca, François Hache, Pascale Changenetbarret, Haik Chosrowjan, Seiji Taniguchi, Pascal Plaza, Yasushi Imamoto
    Abstract:

    Motions of the trans-p-coumaric acid carbonyl group following the photoexcitation of the R52Q mutant of Photoactive Yellow Protein (PYP) are investigated, for the first time, by ultrafast time-resolved circular dichroism (TRCD) spectroscopy. TRCD is monitored in the near-ultraviolet, over a time scale of 10 ps. Immediately after excitation, TRCD is found to exhibit a large negative peak, which decays within a few picoseconds. A quantitative analysis of the signals shows that, upon excitation, the carbonyl group undergoes a fast (≪0.8 ps) and unidirectional flipping motion in the excited state with an angle of ca. 17–53°. For the subset of Proteins that do not enter the signaling photocycle, TRCD provides strong evidence that the carbonyl group moves back to its initial position, leading to the formation of a nonreactive ground-state intermediate of trans conformation. The initial ground state is then restored within ca. 3 ps. Comparative study of R52Q and wild-type PYP provides direct evidence that the ab...

  • interaction between n terminal loop and β scaffold of Photoactive Yellow Protein
    Photochemistry and Photobiology, 2008
    Co-Authors: Yasushi Imamoto, Mikio Kataoka, Miki Harigai
    Abstract:

    : During the photoreaction cycle of Photoactive Yellow Protein (PYP), a physiologically active intermediate (PYP(M)) is formed as a consequence of global Protein conformational change. Previous studies have demonstrated that the photocycle of PYP is regulated by the N-terminal loop region, which is located across the central beta-sheet from the p-coumaric acid chromophore. In this paper, the hydrophobic interaction between N-terminal loop and beta-sheet was studied by characterizing PYP mutants of the hydrophobic residues. The rate constants and structural changes of the photocycle of L15A and L23A possibly participating in such an interaction were more similar to wild-type than F6A, showing that the CH/pi interaction between Phe6 and Lys123 is the most essential as reported previously. To better understand the interactions between N-terminal tail and beta-sheet of PYP, Phe6 and Phe121 were replaced by Cys and linked by a disulfide bond. Since the photocycle kinetics, structural change and thermal stability of F6C/F121C were similar to F6A, the CH/pi interaction between Phe6 and Lys123 is not substitutable. It is likely that the detachment of position 6 from position 123 substantially alters the nature of PYP.

  • A single CH/pi weak hydrogen bond governs stability and the photocycle of the Photoactive Yellow Protein.
    Journal of the American Chemical Society, 2006
    Co-Authors: Miki Harigai, Yasushi Imamoto
    Abstract:

    Importance of the CH/pi interaction on the structure and function of the Photoactive Yellow Protein (PYP) was substantiated. Focusing on the phenyl ring of Phe6 adjacent to the alkyl chain of Lys123, the mutants for these amino acid residues were characterized. The results demonstrated that the mutants lacking the pi-electron at position 6 or the alkyl chain at position 123 show substantial malfunction. This is a clear example that single CH/pi weak interaction plays a crucial role in the normal action of the Protein.

  • primary photoreaction of Photoactive Yellow Protein studied by subpicosecond nanosecond spectroscopy
    Biochemistry, 2001
    Co-Authors: Yasushi Imamoto, Fumio Tokunaga, Tsuyoshi Asahi, Hiroshi Masuhara
    Abstract:

    The primary photochemical event of Photoactive Yellow Protein (PYP) was studied by laser flash photolysis experiments on a subpicosecond−nanosecond time scale. PYP was excited by a 390-nm pulse, and the transient difference absorption spectra were recorded by a multichannel spectrometer for a more reliable spectral analysis than previously possible. Just after excitation, an absorbance decrease due to the stimulated emission at 500 nm and photoconversion of PYP at 450 nm were observed. The stimulated emission gradually shifted to 520 nm and was retained up to 4 ps. Then, the formation of a red-shifted intermediate with a broad absorption spectrum was observed from 20 ps to 1 ns. Another red-shifted intermediate with a narrow absorption spectrum was formed after 2 ns and was stable for at least 5 ns. The latter is therefore believed to correspond to I1 (PYPL), which has been detected on a nanosecond time scale or trapped at −80 °C. Singular value decomposition analysis demonstrated that the spectral shifts...

Klaas J. Hellingwerf - One of the best experts on this subject based on the ideXlab platform.

  • confinement in crystal lattice alters entire photocycle pathway of the Photoactive Yellow Protein
    Nature Communications, 2020
    Co-Authors: Patrick E Konold, Ivo H M Van Stokkum, Klaas J. Hellingwerf, Enis Arik, Jorn Weisenborn, Jos C Arents, John T M Kennis, Marie Louise Groot
    Abstract:

    Femtosecond time-resolved crystallography (TRC) on Proteins enables resolving the spatial structure of short-lived photocycle intermediates. An open question is whether confinement and lower hydration of the Proteins in the crystalline state affect the light-induced structural transformations. Here, we measured the full photocycle dynamics of a signal transduction Protein often used as model system in TRC, Photoactive Yellow Protein (PYP), in the crystalline state and compared those to the dynamics in solution, utilizing electronic and vibrational transient absorption measurements from 100 fs over 12 decades in time. We find that the photocycle kinetics and structural dynamics of PYP in the crystalline form deviate from those in solution from the very first steps following photon absorption. This illustrates that ultrafast TRC results cannot be uncritically extrapolated to in vivo function, and that comparative spectroscopic experiments on Proteins in crystalline and solution states can help identify structural intermediates under native conditions.

  • Confinement in crystal lattice alters entire photocycle pathway of the Photoactive Yellow Protein
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Patrick E Konold, Ivo H M Van Stokkum, Klaas J. Hellingwerf, Enis Arik, Jos C Arents, John T M Kennis, Jörn Weißenborn, Marie Louise Groot
    Abstract:

    Protein structural dynamics can be studied by time-resolved crystallography (TRC) and ultrafast transient spectroscopic methods. Here, the authors perform electronic and vibrational transient absorption measurements to characterise the full photocycle of Photoactive Yellow Protein (PYP) both in the crystalline and solution state and find that the photocycle kinetics and structural intermediates of PYP deviate in the crystalline state, which must be taken into consideration when planning TRC experiments

  • Photoactive Yellow Protein: Converting Light into a Metastable Structural Change
    2017
    Co-Authors: Marie Louise Groot, Klaas J. Hellingwerf
    Abstract:

    Two questions at the forefront of biophysical sciences are biological sensing and energy conversion. Photoactive Yellow Protein is at the crossing point of these two topics as it converts light energy into a structural change in the process of biological light sensing. This bacterial photosensor is an excellent model system to study how a Protein achieves such a function as it is relatively small and very stable. Over the years crystallography, spectroscopy, and multiscale modeling techniques have been applied to study the first step in the signal transduction process that it catalyzes- the ultrafast isomerization of the p-coumaric acid chromophore intrinsic to PYP. This has culminated in an ever-better understanding of the mechanism of its isomerization and the role of the Protein in this process. Here we provide a review of the current state of knowledge on this issue.

  • Photoactive Yellow Protein Studied by Ultraviolet-Visible Transient Absorption Spectroscopy
    2016
    Co-Authors: Author(s S. Yeremenko, Ivo H M Van Stokkum, Klaas J. Hellingwerf, K. Moffat, Sergey Yeremenko, Keith Y Moffat
    Abstract:

    Type article Title Influence of the crystalline state on photoinduced dynamics of Photoactive Yellow Protein studied by ultraviolet-visible transient absorption spectroscop

  • the solution structure of a transient photoreceptor intermediate δ25 Photoactive Yellow Protein
    Structure, 2005
    Co-Authors: Cedric Bernard, Michael A. Van Der Horst, Klaas J. Hellingwerf, Rolf Boelens, Robert Kaptein, Klaartje Houben, N M Derix, David Marks, Nico A J Van Nuland
    Abstract:

    The N-terminally truncated variant of Photoactive Yellow Protein (Delta25-PYP) undergoes a very similar photocycle as the corresponding wild-type Protein (WT-PYP), although the lifetime of its light-illuminated (pB) state is much longer. This has allowed determination of the structure of both its dark- (pG) as well as its pB-state in solution by nuclear magnetic resonance (NMR) spectroscopy. The pG structure shows a well-defined fold, similar to WT-PYP and the X-ray structure of the pG state of Delta25-PYP. In the long-lived photocycle intermediate pB, the central beta sheet is still intact, as well as a small part of one alpha helix. The remainder of pB is unfolded and highly flexible, as evidenced by results from proton-deuterium exchange and NMR relaxation studies. Thus, the partially unfolded nature of the presumed signaling state of PYP in solution, as suggested previously, has now been structurally demonstrated.

Fumio Tokunaga - One of the best experts on this subject based on the ideXlab platform.

  • Raman Optical Activity Probing Structural Deformations of the 4‑Hydroxycinnamyl Chromophore in Photoactive Yellow Protein
    2015
    Co-Authors: Takahito Shingae, Fumio Tokunaga, Masato Kumauchi, Kensuke Kubota, Masashi Unno
    Abstract:

    Many biological cofactors, such as light-absorbing chromophores in photoreceptors, contain a π-electron system and are planar molecules. These cofactors are, however, usually nonplanar within a Protein environment, and such structural distortions have been shown to be functionally important. Because the nonplanar structure makes the molecule chiral, Raman optical activity (ROA) provides a wealth of stereochemical information about the structural and conformational details of cofactors. The present study applied a near-infrared excited ROA to Photoactive Yellow Protein, a blue light receptor. We successfully obtained the ROA spectra of the 4-hydroxycinnamyl chromophore embedded in a Protein environment. Furthermore, calculations of the ROA spectra utilizing density functional theory provide detailed structural information, such as data on out-of-plane distortions of the chromophore. The structural information obtained from the ROA spectra includes the positions of hydrogen atoms, which are usually not detected in the crystal structures of biological samples

  • Coherent oscillations in ultrafast fluorescence of Photoactive Yellow Protein.
    The Journal of chemical physics, 2007
    Co-Authors: Ryosuke Nakamura, Hideki Ichida, Norio Hamada, Yasuo Kanematsu, Fumio Tokunaga
    Abstract:

    The ultrafast photoinduced dynamics of Photoactive Yellow Protein in aqueous solution were studied at room temperature by femtosecond fluorescence spectroscopy using an optical Kerr-gate technique. Coherent oscillations of the wave packet were directly observed in the two-dimensional time-energy map of ultrafast fluorescence with 180fs time resolution and 5nm spectral resolution. The two-dimensional map revealed that four or more oscillatory components exist within the broad bandwidth of the fluorescence spectrum, each of which is restricted in the respective narrow spectral region. Typical frequencies of the oscillatory modes are 50 and 120cm−1. In the landscape on the map, the oscillatory components were recognized as the ridges which were winding and descending with time. The amplitude of the oscillatory and winding behaviors is a few hundred cm−1, which is the same order as the frequencies of the oscillations. The mean spectral positions of the oscillatory components in the two-dimensional map are wel...

  • Low-Frequency Vibrations and Their Role in Ultrafast Photoisomerization Reaction Dynamics of Photoactive Yellow Protein
    The Journal of Physical Chemistry B, 2004
    Co-Authors: Haik Chosrowjan, Norio Hamada, Seiji Taniguchi, Noboru Mataga, Masashi Unno, Seigo Yamauchi, And Masato Kumauchi, Fumio Tokunaga
    Abstract:

    Low-frequency vibrational modes of the native Photoactive Yellow Protein (PYP) and its several mutant and analogue systems have been investigated in “time” (femtosecond fluorescence up-conversion) ...

  • assignment of resonance raman spectrum of Photoactive Yellow Protein in its long lived blue shifted intermediate
    Journal of Physical Chemistry B, 2003
    Co-Authors: Masashi Unno, Fumio Tokunaga, Masato Kumauchi, Jun Sasaki, Seigo Yamauchi
    Abstract:

    Photoactive Yellow Protein (PYP) is a bacterial photoreceptor containing a 4-hydroxycinnamyl chromophore. We report the resonance Raman spectra for the long-lived blue-shifted intermediate of PYP whose chromophore is isotopically labeled with 13C at the carbonyl carbon atom or at the ring carbon atoms. Spectra have been also measured with PYP in D2O where the phenolic hydroxyl group of the chromophore is deuterated. All of the observed Raman bands are assigned on the basis of the observed isotope shifts and normal mode calculations using a density functional theory. The complete assignment provides a satisfactory framework for future investigations of the photocycle mechanism in PYP by vibrational spectroscopy.

  • primary photoreaction of Photoactive Yellow Protein studied by subpicosecond nanosecond spectroscopy
    Biochemistry, 2001
    Co-Authors: Yasushi Imamoto, Fumio Tokunaga, Tsuyoshi Asahi, Hiroshi Masuhara
    Abstract:

    The primary photochemical event of Photoactive Yellow Protein (PYP) was studied by laser flash photolysis experiments on a subpicosecond−nanosecond time scale. PYP was excited by a 390-nm pulse, and the transient difference absorption spectra were recorded by a multichannel spectrometer for a more reliable spectral analysis than previously possible. Just after excitation, an absorbance decrease due to the stimulated emission at 500 nm and photoconversion of PYP at 450 nm were observed. The stimulated emission gradually shifted to 520 nm and was retained up to 4 ps. Then, the formation of a red-shifted intermediate with a broad absorption spectrum was observed from 20 ps to 1 ns. Another red-shifted intermediate with a narrow absorption spectrum was formed after 2 ns and was stable for at least 5 ns. The latter is therefore believed to correspond to I1 (PYPL), which has been detected on a nanosecond time scale or trapped at −80 °C. Singular value decomposition analysis demonstrated that the spectral shifts...

Hyotcherl Ihee - One of the best experts on this subject based on the ideXlab platform.

  • Kinetics of the E46Q mutant of Photoactive Yellow Protein investigated by transient grating spectroscopy
    ELSEVIER SCIENCE BV, 2018
    Co-Authors: Cheolhee Yang, Jungkweon Choi, Young-min Kim, Tae Wu Kim, Sang Jin Lee, Hyotcherl Ihee
    Abstract:

    To elucidate the role of internal proton transfer in the photodynamics of Photoactive Yellow Protein (PYP), the photocycle of the Glu46Gln mutant of PYP (E46Q-PYP) is investigated by transient grating (TG) spectroscopy. Compared with wild-type PYP (wt-PYP), the first spectrally blue-shifted intermediate of E46Q-PYP is formed more slowly, which is consistent with the absence of direct protonation from Glu46 residue, if the parallel kinetic model for wt-PYP is invoked. The smaller conformational change in E46Q-PYP, as manifested by the smaller change in the diffusion coefficient, mainly arises from the relatively larger volume of the ground state E46Q-PYP than wt-PYP rather than from the smaller volume of the pB state. (c) 2017 Elsevier B.V. All rights reserved.1

  • High-throughput instant quantification of Protein expression and purity based on Photoactive Yellow Protein turn off/on label
    WILEY-BLACKWELL, 2018
    Co-Authors: Young-min Kim, Prabhakar Ganesan, Hyotcherl Ihee
    Abstract:

    Quantifying the concentration and purity of a target Protein is essential for highthroughput Protein expression test and rapid screening of highly soluble Proteins. However, conventional methods such as PAGE and dot blot assay generally involve multiple time-consuming tasks requiring hours or do not allow instant quantification. Here, we demonstrate a new method based on the Photoactive Yellow Protein turn Off/On Label (POOL) system that can instantly quantify the concentration and purity of a target Protein. The main idea of POOL is to use Photoactive Yellow Protein (PYP), or its miniaturized version, as a fusion partner of the target Protein. The characteristic blue light absorption and the consequent Yellow color of PYP is absent when initially expressed without its chromophore, but can be turned on by binding its chromophore, p-coumaric acid. The appearance of Yellow color upon adding a precursor of chromophore to the coexpressed PYP can be used to check the expression amount of the target Protein via visual inspection within a few seconds as well as to quantify its concentration and purity with the aid of a spectrometer within a few minutes. The concentrations measured by the POOL method, which usually takes a few minutes, show excellent agreement with those by the BCA Kit, which usually takes ~1 h. We demonstrate the applicability of POOL in E. coli, insect, and mammalian cells, and for highthroughput Protein expression screening7

  • High-throughput instant quantification of Protein expression and purity based on Photoactive Yellow Protein turn off/on label
    'Wiley', 2018
    Co-Authors: Young-min Kim, Prabhakar Ganesan, Hyotcherl Ihee
    Abstract:

    Quantifying the concentration and purity of a target Protein is essential for highthroughput Protein expression test and rapid screening of highly soluble Proteins. However, conventional methods such as PAGE and dot blot assay generally involve multiple time-consuming tasks requiring hours or do not allow instant quantification. Here, we demonstrate a new method based on the Photoactive Yellow Protein turn Off/On Label (POOL) system that can instantly quantify the concentration and purity of a target Protein. The main idea of POOL is to use Photoactive Yellow Protein (PYP), or its miniaturized version, as a fusion partner of the target Protein. The characteristic blue light absorption and the consequent Yellow color of PYP is absent when initially expressed without its chromophore, but can be turned on by binding its chromophore, p-coumaric acid. The appearance of Yellow color upon adding a precursor of chromophore to the coexpressed PYP can be used to check the expression amount of the target Protein via visual inspection within a few seconds as well as to quantify its concentration and purity with the aid of a spectrometer within a few minutes. The concentrations measured by the POOL method, which usually takes a few minutes, show excellent agreement with those by the BCA Kit, which usually takes ~1 h. We demonstrate the applicability of POOL in E. coli, insect, and mammalian cells, and for highthroughput Protein expression screening1771sciescopu

  • Correction to “Photocycle of Photoactive Yellow Protein in Cell-Mimetic Environments: Molecular Volume Changes and Kinetics”
    2017
    Co-Authors: Cheolhee Yang, Seong Ok Kim, Yonggwan Kim, So Ri Yun, Jungkweon Choi, Hyotcherl Ihee
    Abstract:

    Correction to “Photocycle of Photoactive Yellow Protein in Cell-Mimetic Environments: Molecular Volume Changes and Kinetics

  • Measurements of complex refractive indices of Photoactive Yellow Protein
    arXiv: Chemical Physics, 2015
    Co-Authors: Kyeoreh Lee, Hyotcherl Ihee, Young-min Kim, Jaehwang Jung, Yongkeun Park
    Abstract:

    A novel optical technique for measuring the complex refractive index (CRI) of Photoactive Proteins over the wide range of visible wavelengths is presented. Employing quantitative phase microscopy equipped with a wavelength swept source, optical fields transmitted from a solution of Photoactive Proteins were precisely measured, from which the CRIs of the Photoactive Proteins were retrieved with the Fourier light scattering technique. Using the present method, both the real and imaginary RIs of a Photoactive Yellow Protein (PYP) solution were precisely measured over a broad wavelength range (461 - 582 nm). The internal population of the ground and excited states were switched by blue light excitation (445 nm center wavelength), and the broadband refractive index increments of each state were measured. The significant CRI deviation between in the presence and absence of the blue excitation was quantified and explained based on the Kramers-Kronig relations.

Gerrit Groenhof - One of the best experts on this subject based on the ideXlab platform.

  • Hydrogen bonding controls excited-state decay of the Photoactive Yellow Protein chromophore
    2016
    Co-Authors: Martial Boggio-pasqua, Michael A. Robb, Gerrit Groenhof
    Abstract:

    Photoactive Yellow Protein (PYP) is believed to be the primary photoreceptor for the photoavoidance response of the salt-tolerant bacterium Halorhodospira halophila. PYP contains a deprotonated 4-hydroxy-cinnamic acid (or p-coumaric acid, pca) chromophore linked covalently to the γ-sulfur of Cys69 Via a thioester bond.1 Upon absorbing a blue-light photon, PYP enters a fully reversible photocycle involving several intermediates on a time scale spanning from a few hundred femtoseconds to seconds.2 In previous works we have used mixed quantum/classical (QM/MM) simulations to reveal the detailed sequence of structural changes that follows photon absorption in both wild-type PYP3 and the Arg52Gln mutant.4 The first step is a photoisomerization of the chromophore of the double (wt-PYP) or single bond (Arg52Gln). In the Protein radiationless decay from the excited state is very efficient because the intersection seam between the ground- (S0) and excited-stat

  • femtosecond structural dynamics drives the trans cis isomerization in Photoactive Yellow Protein
    Science, 2016
    Co-Authors: Kanupriya Pande, Gerrit Groenhof, C. Hutchison, Andrew Aquila, Josef S. Robinson, Jason Tenboer, Shibom Basu, Sébastien Boutet, Daniel P. Deponte, Mengning Liang
    Abstract:

    A variety of organisms have evolved mechanisms to detect and respond to light, in which the response is mediated by Protein structural changes after photon absorption. The initial step is often the photoisomerization of a conjugated chromophore. Isomerization occurs on ultrafast time scales and is substantially influenced by the chromophore environment. Here we identify structural changes associated with the earliest steps in the trans-to-cis isomerization of the chromophore in Photoactive Yellow Protein. Femtosecond hard x-ray pulses emitted by the Linac Coherent Light Source were used to conduct time-resolved serial femtosecond crystallography on Photoactive Yellow Protein microcrystals over a time range from 100 femtoseconds to 3 picoseconds to determine the structural dynamics of the photoisomerization reaction.

  • Femtosecond structural dynamics drives the trans/cis isomerization in Photoactive Yellow Protein.
    Science (New York N.Y.), 2016
    Co-Authors: Kanupriya Pande, Gerrit Groenhof, C. Hutchison, Andrew Aquila, Josef S. Robinson, Jason Tenboer, Shibom Basu, Sébastien Boutet, Daniel P. Deponte, Mengning Liang
    Abstract:

    A variety of organisms have evolved mechanisms to detect and respond to light, in which the response is mediated by Protein structural changes after photon absorption. The initial step is often the photoisomerization of a conjugated chromophore. Isomerization occurs on ultrafast time scales and is substantially influenced by the chromophore environment. Here we identify structural changes associated with the earliest steps in the trans-to-cis isomerization of the chromophore in Photoactive Yellow Protein. Femtosecond hard x-ray pulses emitted by the Linac Coherent Light Source were used to conduct time-resolved serial femtosecond crystallography on Photoactive Yellow Protein microcrystals over a time range from 100 femtoseconds to 3 picoseconds to determine the structural dynamics of the photoisomerization reaction.

  • 2002b. Signal transduction in the Photoactive Yellow Protein. I. Photon absorption and the isomerization of the chromophore
    2015
    Co-Authors: Gerrit Groenhof, Marc F. Lensink, Herman J. C. Berendsen, Alan E. Mark
    Abstract:

    ABSTRACT Molecular dynamics simulation techniques, together with semiempirical PM3 calcu-lations, have been used to investigate the effect of photoisomerization of the 4-hydroxy-cinnamic acid chromophore on the structural properties of the Photoactive Yellow Protein (PYP) from Ectothioro-dospira halophila. In this bacteria, exposure to blue light leads to a negative photoactic response. The calculations suggest that the isomerization does not directly destabilize the Protein. However, because of the isomerization, a proton transfer from a glu-tamic acid residue (Glu46) to the phenolate oxygen atom of the chromophore becomes energetically favor-able. The proton transfer initiates conformational changes within the Protein, which are in turn be-lieved to lead to signaling. Proteins 2002;48:212–219. © 2002 Wiley-Liss, Inc. Key words: Photoactive Yellow Protein; signal trans-duction; proton transfer; molecular dy-namics; semiempirical PM3 calculation

  • Hydrogen Bonding Controls Excited-State Decay of the Photoactive Yellow Protein Chromophore
    2015
    Co-Authors: Martial Boggio-pasqua, Michael A. Robb, Gerrit Groenhof
    Abstract:

    Hydrogen Bonding Controls Excited-State Decay of the Photoactive Yellow Protein Chromophor