Protein and solvent dynamics of the water-soluble chlorophyll-binding protein (WSCP)

Rusevich, Leonid L.; Embs, Jan Peter; Bektas, Inga; Paulsen, Harald; Ренгер, Г.; Pieper, Jörg

doi:10.1051/epjconf/20158302016

Cited by 6 publications

(9 citation statements)

References 23 publications

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“…Thus, the increased D-value is a quantitative measure for a significantly enhanced protein dynamics of OCP W288A , which can be viewed as a structural analogue of the active-state OCP R . A global diffusion as observed for WSCP 48 or hemoglobin 52 could not be detected on the given time scale of motions. This is consistent with rather slow values of translational diffusion for both OCP forms observed by fluorescence correlation spectroscopy.…”

Section: The Journal Of Physical Chemistry Bmentioning

confidence: 70%

“…In contrast, a protein is expected to be an incoherent scatterer as the vanadium standard; 47 that is, it should display a flat background in the angle spectrum. Following, 48 the OCP W288A contribution is obtained by subtraction of the buffer signal from the sample data under the condition that the coherent peak at ∼100°vanishes according to…”

Section: Resultsmentioning

confidence: 99%

“…In contrast, a protein is expected to be an incoherent scatterer as the vanadium standard; that is, it should display a flat background in the angle spectrum. Following, the OCP W288A contribution is obtained by subtraction of the buffer signal from the sample data under the condition that the coherent peak at ∼100° vanishes according to where k is a scaling factor, which was found to be 0.76 in the case of OCP W288A (and 0.81 in the case of OCP O , not shown). As a result, the OCP W288A contribution to the angle spectrum shown as a red line in Figure is featureless confirming the validity of the approach.…”

Section: Resultsmentioning

confidence: 99%

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Solution Structure and Conformational Flexibility in the Active State of the Orange Carotenoid Protein. Part II: Quasielastic Neutron Scattering

et al. 2019

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Orange carotenoid proteins (OCPs), which are protecting cyanobacterial light-harvesting antennae from photodamage, undergo a pronounced structural change upon light absorption. In addition, the active state is anticipated to boost a significantly higher molecular flexibility similar to a "molten globule" state. Here, we used quasielastic neutron scattering to directly characterize the vibrational and conformational molecular dynamics of OCP in its ground and active states, respectively, on the picosecond time scale. At a temperature of 100 K, we observe mainly (vibronic) inelastic features with peak energies at 5 and 6 meV (40 and 48 cm −1 , respectively). At physiological temperatures, however, two (Lorentzian) quasielastic components represent localized protein motions, that is, stochastic structural fluctuations of protein side chains between various conformational substates of the protein. Global diffusion of OCP is not observed on the given time scale. The slower Lorentzian component is affected by illumination and can be well-characterized by a jump-diffusion model. While the jump diffusion constant D is (2.82 ± 0.01) × 10 −5 cm 2 /s at 300 K in the ground state, it is increased by ∼20% to (3.48 ± 0.01) × 10 −5 cm 2 /s in the active state, revealing a strong enhancement of molecular mobility. The increased mobility is also reflected in the average atomic mean square displacement ⟨u 2 ⟩; we determine a ⟨u 2 ⟩ of 1.47 ± 0.05 Å in the ground state, but 1.86 ± 0.05 Å in the active state (at 300 K). This effect is assigned to two factors: (i) the elongated structure of the active state with two widely separated protein domains is characterized by a larger number of surface residues with a concomitantly higher degree of motional freedom and (ii) a larger number of hydration water molecules bound at the surface of the protein. We thus conclude that the active state of the orange carotenoid protein displays an enhanced conformational dynamics. The higher degree of flexibility may provide additional channels for nonradiative decay so that harmful excess energy can be more efficiently converted to heat.

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Section: The Journal Of Physical Chemistry Bmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Solution Structure and Conformational Flexibility in the Active State of the Orange Carotenoid Protein. Part II: Quasielastic Neutron Scattering

et al. 2019

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“…As pointed out in refs , , these spectra contain information about the dynamics of both LHC II complex and buffer solution. Therefore, INS spectra of the buffer solution were measured separately (blue symbols in Figure A,B) and have to be properly subtracted. ,, The INS spectra of trimeric and monomeric LHC II are rather similar and reveal two inelastic peaks at roughly 2.4 and 6.5 meV, respectively. The latter peak is also found in the buffer spectrum so that it can be mainly attributed to the solvent.…”

Section: Resultsmentioning

confidence: 99%

Rigid versus Flexible Protein Matrix: Light-Harvesting Complex II Exhibits a Temperature-Dependent Phonon Spectral Density

et al. 2018

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Dynamics-function correlations are usually inferred when molecular mobility and protein function are simultaneously impaired at characteristic temperatures or hydration levels. In this sense, excitation energy transfer in the photosynthetic light-harvesting complex II (LHC II) is an untypical example because it remains fully functional even at cryogenic temperatures relying mainly on interactions of electronic states with protein vibrations. Here, we study the vibrational and conformational protein dynamics of monomeric and trimeric LHC II from spinach using inelastic neutron scattering (INS) in the temperature range of 20-305 K. INS spectra of trimeric LHC II reveal a distinct vibrational peak at ∼2.4 meV. At temperatures above ∼160 K, however, the inelastic peak shifts toward lower energies, which is attributed to vibrational anharmonicity. A more drastic shift is observed at about 240 K, which is interpreted in terms of a "softening" of the protein matrix along with the dynamical transition. Monomeric LHC II exhibits a higher degree of conformational mobility at physiological temperatures, which can be attributed to a higher number of solvent-exposed side chains at the protein surface. The effects of the changes in protein dynamics on the spectroscopic properties of LHC II are considered in comparative model calculations. The absorption line shapes of a pigment molecule embedded into LHC II are simulated for the cases of (i) a rigid protein matrix, (ii) a protein matrix with temperature-dependent spectral density of protein vibrations, and (iii) temperature-dependent electron-phonon coupling strength. Our findings indicate that vibrational and conformational protein dynamics affect the spectroscopic (absorption) properties of LHC II at physiological temperatures.

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“…The spectra thus obtained were verified by the static structure factor, S ( Q ), calculated by integrating the S ( Q ,ω) along the ω-direction, examples of which are shown in Figure S1c,d. The QENS spectra of the D 2 O-solution samples and the D 2 O-buffer show increase in intensity at Q > ∼ 1.4 Å –1 , which arises from coherent scattering of D 2 O. , On the other hand, the spectra of the proteins do not contain such a contribution. , Proper subtraction of the D 2 O-buffer spectra should thus provide S ( Q ) with rather flat intensity at Q > ∼ 1.4 Å –1 . As shown in Figure S1c,d, whereas increase in intensity at Q ≥ 1.4 Å –1 is observed in the curves of the solution sample and the buffer, such increase disappears in the difference curves.…”

Section: Experimental Methodsmentioning

confidence: 98%

Ligation-Dependent Picosecond Dynamics in Human Hemoglobin As Revealed by Quasielastic Neutron Scattering

et al. 2017

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Hemoglobin, the vital O carrier in red blood cells, has long served as a classic example of an allosteric protein. Although high-resolution X-ray structural models are currently available for both the deoxy tense (T) and fully liganded relaxed (R) states of hemoglobin, much less is known about their dynamics, especially on the picosecond to subnanosecond time scales. Here, we investigate the picosecond dynamics of the deoxy and CO forms of human hemoglobin using quasielastic neutron scattering under near physiological conditions in order to extract the dynamics changes upon ligation. From the analysis of the global motions, we found that whereas the apparent diffusion coefficients of the deoxy form can be described by assuming translational and rotational diffusion of a rigid body, those of the CO form need to involve an additional contribution of internal large-scale motions. We also found that the local dynamics in the deoxy and CO forms are very similar in amplitude but are slightly lower in frequency in the former than in the latter. Our results reveal the presence of rapid large-scale motions in hemoglobin and further demonstrate that this internal mobility is governed allosterically by the ligation state of the heme group.

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Protein and solvent dynamics of the water-soluble chlorophyll-binding protein (WSCP)

Cited by 6 publications

References 23 publications

Solution Structure and Conformational Flexibility in the Active State of the Orange Carotenoid Protein. Part II: Quasielastic Neutron Scattering

Solution Structure and Conformational Flexibility in the Active State of the Orange Carotenoid Protein. Part II: Quasielastic Neutron Scattering

Rigid versus Flexible Protein Matrix: Light-Harvesting Complex II Exhibits a Temperature-Dependent Phonon Spectral Density

Ligation-Dependent Picosecond Dynamics in Human Hemoglobin As Revealed by Quasielastic Neutron Scattering

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