Detection of structural changes upon oxidation in multinuclear Mn–oxo–carboxylate assemblies by Fourier transform infrared spectroscopy: relationship to photosystem II

Smith, James C.; González‐Vergara, Enrique; Vincent, John B.

doi:10.1016/s0020-1693(96)05350-9

Cited by 35 publications

(51 citation statements)

References 28 publications

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“…These numbers are smaller or on the same order of magnitude as the expected energy gap for bridging carboxylate ligands. For example, in a study of trimeric and dimeric manganese compounds, bridging carboxylates gave rise to energy splitting of 220 to 100 cm Ϫ1 , with the smaller values of ⌬ arising from Mn 3ϩ ⅐Mn 4ϩ dinuclear complexes (39,41). We conclude that the broad lines in Fig.…”

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 65%

“…The CϭO and C-O stretches of the carboxylate are intermediate in frequency between the CϭO and C-O stretching vibrations of the carboxylic acid (35,38). The third explanation is that these groups are ligating manganese and that the oxidation of metal causes a frequency shift of vibrational modes, assignable to the ligand (38,39). On the basis of the pattern of observed frequencies, we favor the third possible explanation of these spectra, as described below.…”

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 77%

“…3C, dotted areas) gives ⌬ equal to 74 cm Ϫ1 for the positive lines and 128 cm Ϫ1 for the negative lines. Although these values can be influenced by the oxidation state of the metal and by cancellation of intensity in the difference spectra (13,39,40), these numbers are far smaller than the expected energy gap between asymmetric and symmetric stretching vibrations of free carboxylates that are not ligating metals. These numbers are smaller or on the same order of magnitude as the expected energy gap for bridging carboxylate ligands.…”

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 91%

“…When carboxylates bind to metals with bridging ligation, the energy gap between the asymmetric and symmetric stretching vibrations may be similar to that of the free carboxylate (38,40). In recent studies, ⌬ was also found to be dependent on the oxidation state of the manganese, (39,40). When carboxylates bind to metals with bidentate ligation, the characteristic spectral change is a decrease in ⌬ between the asymmetric and symmetric modes of the carboxylate (38,40).…”

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 98%

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Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Steenhuis¹,

Hutchison

Barry

1999

Journal of Biological Chemistry

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Photosystem II (PSII) is the photosynthetic enzyme catalyzing the oxidation of water and reduction of plastoquinone (Q). This reaction occurs at a catalytic site containing four manganese atoms and cycling among five oxidation states, the S n states, where n refers to the number of oxidizing equivalents stored. Biochemical and spectroscopic techniques have been used previously to conclude that aspartate 170 in the D1 subunit influences the structure and function of the PSII active site (Boerner, R. J., Nguyen, A. P., Barry, B. A., and Debus, R. J. (1992) Biochemistry 31, 6660 -6672). Substitution of glutamate for aspartate 170 resulted in an assembled manganese cluster, which was capable of enzymatic turnover, but at lower steady-state oxygen evolution rates. Here, we obtained the difference (lightminus-dark) Fourier transform IR spectrum associated with the S 2 Q ؊ -minus-S 1 Q transition by illumination of oxygen-evolving wild-type and DE170D1 PSII preparations at 200 K. These spectra are known to be dominated by contributions from carboxylic acid and carboxylate residues that are close to or ligating the manganese cluster. Substitution of glutamate for aspartate 170 results in alterations in the S 2 Q ؊ -minus-S 1 Q spectrum; the alterations are consistent with a change in carboxylate coordination to manganese or calcium. In particular, the spectra are consistent with a shift from bridging/ bidentate carboxylates in wild-type PSII to unidentate carboxylate ligation in DE170D1 PSII.Photosystem II (PSII) 1 is the photosynthetic reaction center that is responsible for the light-driven oxidation of water and the reduction of quinone in plants, green algae, and cyanobacteria. The catalytic site contains a tetranuclear manganese cluster, and the catalytic cycle of water oxidation has been proposed to consist of five oxidation states (S n ) called the JoliotKok S states. The subscript n refers to the number of oxidizing equivalents stored at the active site. Absorption of four photons and four corresponding charge separations are necessary to complete one catalytic cycle. Each cycle results in the oxidation of two water molecules to form one molecule of molecular oxygen and four protons. Calcium is required for oxygen evolution and may be bound in proximity to the manganese cluster (reviewed in Refs. 1 and 2).Many studies of PSII have focused on the S 2 state (for review, see Ref. 3). Dark adaptation at room temperature sets the catalytic center to the S 1 state because S 0 converts to S 1 by reduction of tyrosine radical, D ⅐ (4, 5). Two different EPR signals, a g ϭ 2 multiline signal (6) and a g ϭ 4.1 signal (7), are observed from the S 2 state. Illumination of plant or cyanobacterial PSII at 200 K results in the formation of the g ϭ 2 multiline EPR signal (for examples, see Refs. 6 and 8) and an EPR signal from Fe 2ϩ Q A Ϫ (9). The S 1 -to-S 2 transition is associated with oxidation of manganese, probably from Mn 3ϩ to Mn 4ϩ (reviewed in Ref. 10). Recently, we have obtained the difference FT-IR spectrum associate...

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Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 65%

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 77%

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 91%

Section: Interpretation Of the Lines In The 1750 To 1670 CMmentioning

confidence: 98%

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Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Steenhuis¹,

Hutchison

Barry

1999

Journal of Biological Chemistry

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“…This is, however, quite difficult to rationally explain. Alternatively, the observed band change was reproduced by the upshift of an S 2 /S 1 band pair from 1395/1346 (or 1360/1345) cm Ϫ1 to 1403/1360 (or 1404/1392) cm Ϫ1 , although the presumed shift opposes the expected trends of the ligand (5,35). It was indicated that the symmetric stretching modes of the ␣-carboxylate group of the D1 C-terminal Ala-344 appear at ϳ1356 cm Ϫ1 for the S 1 state and at ϳ1320 cm Ϫ1 for the S 2 state (30), respectively.…”

Section: Discussionmentioning

confidence: 94%

Impact of Replacement of D1 C-terminal Alanine with Glycine on Structure and Function of Photosynthetic Oxygen-evolving Complex

Mizusawa

Kimura

Ishii

et al. 2004

Journal of Biological Chemistry

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The C-terminal alanine 344 (Ala-344) in the D1 protein of photosystem II is conserved in all of the organisms performing oxygenic photosynthesis. A free ␣-COO ؊ of Ala-344 has been proposed to be responsible for ligating the Mn cluster. Here, we constructed a mutant having D1 in which D1-Ala-344 was replaced with glycine (Gly) in cyanobacterium Synechocystis sp. PCC 6803. The effects of this minimal change in the side group from methyl to hydrogen on the properties of the oxygenevolving complex were comprehensively investigated using purified core particles. The mutant grew photoautotrophically, and little change was observed in the protein composition of the oxygen-evolving core particles. The Gly-substituted oxygen-evolving complex showed small but normal S 2 multiline and enhanced g ‫؍‬ 4.1 electron spin resonance signals and S 2 -state thermoluminescence bands with slightly elevated peak temperature. The Gly substitution resulted in distinct but relatively small changes in a few bands arising from the putative carboxylate ligand for the Mn cluster in the mid-frequency (1800 -1000 cm ؊1 ) S 2 /S 1 Fourier transform infrared difference spectrum. In contrast, the low frequency (670 -350 cm ؊1 ) S 2 /S 1 Fourier transform infrared difference spectrum was markedly changed by the substitution. The results indicate that the internal structure of the Mn cluster and/or the interaction between the Mn cluster and its ligand are considerably altered by a simple change in the side group, from methyl to hydrogen, at the C-terminal of the D1 protein.Photosynthetic water oxidation takes place in an oxygenevolving complex (OEC) 1 in which the catalytic center is composed of a tetranuclear Mn cluster located on the lumenal side of the D1/D2 heterodimer. Two water molecules are oxidized to an oxygen molecule through five intermediates labeled S n (n ϭ 0 -4), where n denotes the number of oxidizing equivalents stored. In a dark-adapted sample, a thermally stable S 1 state predominates. The S n state advances to the S nϩ1 state by absorbing each photon to reach the highest oxidation state, S 4 , which spontaneously relaxes to the lowest oxidation state, S 0 , concomitant with the release of an oxygen molecule (1, 2).Studies using chemical modifiers (3) and electron spin echo envelope modulation (4) and FTIR spectroscopy (5, 6) suggested that histidine and/or acidic amino acids are involved in the ligation of the Mn cluster. Several residues of the D1 protein have been proposed based on site-directed mutagenesis studies mainly using cyanobacterium Synechocystis sp. PCC 6803 as potential candidates for the ligands to the Mn cluster, (reviewed in Refs. 7-9). They are , some of which were arranged in close proximity to the Mn cluster in x-ray structural models of photosystem (PS) . However, the properties of OEC have not been characterized using isolated PS II preparations with the exception of a few mutants. The studies using the O 2 -evolving PS II core particles from the D1-D170H mutant showed that the mutation leads to little ...

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Magnetic and Spectroscopic Study on a New Asymmetric Mixed‐valence Mn₂(II,III) Coordination Compound

Jung

Rentschler

2015

Zeitschrift anorg allge chemie

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A new dinuclear mixed-valence compound [Mn II Mn III (bttpnol)(O 2 C-C 6 H 4 -NO 2 ) 2 ]ClO 4 was synthesized by using the asymmetric heptadentate ligand N-(2-hydroxybenzyl)-N,NЈ,NЈtris(2-pyridylmethyl)-1,3-diaminopropan-2-ol (H 2 btppnol). One central manganese atom assumes N 3 O 3 and the other N 2 O 4 coordination sphere. Both manganese ions are bridged by the alkoxy-group of the dinucleating ligand and two bidentate carboxylate groups of the nitrobenzoate ligands. The structural data show clearly that Mn III prefers

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Detection of structural changes upon oxidation in multinuclear Mn–oxo–carboxylate assemblies by Fourier transform infrared spectroscopy: relationship to photosystem II

Cited by 35 publications

References 28 publications

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Impact of Replacement of D1 C-terminal Alanine with Glycine on Structure and Function of Photosynthetic Oxygen-evolving Complex

Magnetic and Spectroscopic Study on a New Asymmetric Mixed‐valence Mn₂(II,III) Coordination Compound

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Detection of structural changes upon oxidation in multinuclear Mn–oxo–carboxylate assemblies by Fourier transform infrared spectroscopy: relationship to photosystem II

Cited by 35 publications

References 28 publications

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Alterations in Carboxylate Ligation at the Active Site of Photosystem II

Impact of Replacement of D1 C-terminal Alanine with Glycine on Structure and Function of Photosynthetic Oxygen-evolving Complex

Magnetic and Spectroscopic Study on a New Asymmetric Mixed‐valence Mn2(II,III) Coordination Compound

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Magnetic and Spectroscopic Study on a New Asymmetric Mixed‐valence Mn₂(II,III) Coordination Compound