Comparison of the Stacking of Chlorophylls in Chlorosomes Versus Aggregates of Bacteriochlorophyll C and Chlorophyll A using 2-D MAS NMR Spectroscopy

Boender, G. J.; Balaban, Teodor Silviu; Holzwarth, Alfred R.; Schaffner, Kurt; Raap, J.; Prytulla, S.; Oschkinat, Hartmut; Groot, Huub J. M. de

doi:10.1007/978-94-009-0173-5_82

Cited by 10 publications

(5 citation statements)

References 7 publications

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“…2-D CP/MAS 13 C homonuclear dipolar correlation spectra collected from intact 13 C-enriched chlorosomes revealed that the BChl c in the chlorosomes is in a pure chlorophyll aggregate without intrinsic protein units (). The structure was partially resolved with MAS NMR and it was deduced that the BChl c forms stacks ( , ), in line with the chromophore arrangement in the parallel chain model ( , ). The NMR lines are inhomogeneously broadened, indicating that the stacks are partially disordered ().…”

mentioning

confidence: 70%

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

Rossum¹,

Steensgaard²,

Mulder³

et al. 2001

Biochemistry

148

194

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Heteronuclear 2-D and 3-D magic-angle spinning NMR dipolar correlation spectroscopy was applied to determine solid-state (1)H shifts for aggregated bacteriochlorophyll c (BChl c) in uniformly (13)C-enriched light harvesting chlorosomes of the green photosynthetic bacterium Chlorobium tepidum. A complete assignment of 29 different observable resonances of the 61 protons of the aggregated BChl c in the intact chlorosomes is obtained. Aggregation shifts relative to monomeric BChl c in solution are detected for protons attached to rings I, II, and III/V and to their side chains. The 2(1)-H(3), 3(2)-H(3), and 3(1)-H resonances are shifted upfield by -2.2, -1, and -3.3 ppm, respectively, relative to monomeric BChl c in solution. Although the resonances are inhomogeneously broadened and reveal considerable global structural heterogeneity, the 5-CH and the 7-Me responses are doubled, which provides evidence for the existence of at least two relatively well-defined structurally different arrangements. Ab initio quantum chemical modeling studies were performed to refine a model for the self-assembled BChl c with two different types of BChl stacks. The BChl in the stacks can adopt either anti- or syn-configuration of the coordinative bond, where anti and syn designate the relative orientation of the Mg-OH bond relative to the direction of the 17-17(1) bond. The analogy between aggregation shifts for BChl c in the chlorosome and for self-assembled chlorophyll a/H(2)O is explored, and a bilayer model for the tubular supra-structure of sheets of BChl c is proposed, from a homology modeling approach.

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mentioning

confidence: 70%

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

Rossum¹,

Steensgaard²,

Mulder³

et al. 2001

Biochemistry

148

194

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“…This pulse sequence is similar to the RFDR pulse sequences proposed earlier. 16,17 Following the 1 H 90°preparation pulse, RAMP-amplitude CP is applied to transfer magnetization from 1 H to 13 C. The RAMP-amplitude CP was varied from 100% to 50% during this preparation step. The protons were decoupled from the carbon by use of the two-pulse phase modulation (TPPM) 18 decoupling scheme during 13 C evolution and detection, while continuous wave (CW) decoupling was applied during mixing in the homonuclear ( 13 C-13 C) experiments.…”

Section: Methodsmentioning

confidence: 99%

Ultrahigh Field MAS NMR Dipolar Correlation Spectroscopy of the Histidine Residues in Light-Harvesting Complex II from Photosynthetic Bacteria Reveals Partial Internal Charge Transfer in the B850/His Complex

et al. 2001

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Low-temperature 15N and 13C CP/MAS (cross-polarization/magic angle spinning) NMR has been used to analyze BChl-histidine interactions and the electronic structure of histidine residues in the light-harvesting complex II (LH2) of Rhodopseudomonas acidophila. The histidines were selectively labeled at both or one of the two nitrogen sites of the imidazole ring. The resonances of histidine nitrogens that are interacting with B850 BChl a have been assigned. Specific 15N labeling confirmed that it is the tau-nitrogen of histidines which is ligated to Mg2+ of B850 BChl molecules (beta-His30, alpha-His31). The pi-nitrogens of these Mg2+-bound histidines were found to be protonated and may be involved in hydrogen bond interactions. Comparison of the 2-D MAS NMR homonuclear (13C-13C) dipolar correlation spectrum of [13C6,15N3]-histidines in the LH2 complex with model systems in the solid state reveals two different classes of electronic structures from the histidines in the LH2. In terms of the 13C isotropic shifts, one corresponds to the neutral form of histidine and the other resembles a positively charged histidine species. 15N-13C double-CP/MAS NMR data provide evidence that the electronic structure of the histidines in the neutral BChl a/His complexes resembles the positive charge character form. While the Mg...15N isotropic shift confirms a partial positive charge transfer, its anisotropy is essentially of the lone pair type. This provides evidence that the hybridization structure corresponding to the neutral form of the imidazole is capable of "buffering" a significant amount of positive charge.

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“…Many high-resolution solidstate 2D 13 C-13 C and 15 N- 13 C chemical shift spectra in solids have been published. 20,21,50,[54][55][56][57][58][59] In particular, 2D methods have been used to assign chemical shifts in solid peptides. 39,57,59,60 These experiments have incorporated pulse sequences that are similar to that shown in Figure 1 and that employ initial CP transfer from 1 H to one low-γ nucleus, and then one or two periods of indirect chemical shift evolution connected by heteronuclear and/or homonuclear polarization transfer mixing periods.…”

Section: T H Imentioning

confidence: 99%

“…The optimal choice may depend on the MAS rate, the available decoupling power, and the desired bandwidth. Most experiments thus far have utilized broadband heteronuclear polarization transfer methods 21,22,39,61 and RFDR 18,54,55,[58][59][60] or spin diffusion 14,18,[62][63][64][65] for the homonuclear mixing.…”

Section: T H Imentioning

confidence: 99%

2D and 3D¹⁵N−¹³C−¹³C NMR Chemical Shift Correlation Spectroscopy of Solids: Assignment of MAS Spectra of Peptides

et al. 2000

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Strategies are discussed for resolving and assigning peptide backbone and side chain resonances in uniformly 13 C, 15 N-labeled solid peptides. Methods for 2D 13 C-13 C, 15 N-( 13 C)-13 C, and 3D 15 N-13 C-13 C chemical shift correlation spectroscopy are demonstrated in the chemotactic tripeptide N-formyl-[U-13 C, 15 N]-Met-Leu-Phe-OH (MLF). Band-selective heteronuclear double-cross polarization (DCP) and γ-encoded homonuclear double-quantum mixing provide large improvements in sensitivity relative to previously published methods. Directional transfers from amide 15 N to 13 C′ or 13 C R resonances provide two-to 3-fold improvements in signal intensity on the observed 13 C spin, in comparison to broadband DCP. Similarly, homonuclear 13 C-13 C transfer is enhanced by use of the rotating frame sequence SPC-5; backbone-to-side chain polarization transfers are achieved with especially high efficiency. Furthermore, the double-quantum nature of the homonuclear transfer permits straightforward classification of C′, C R , C β , and C γ signals, on the basis of the sign of the cross-peaks. The experiments described here include optimized solid-state analogues of the solutionstate schemes commonly employed for amino acid identification and sequential backbone assignment. We expect that these experiments will facilitate application of 2D and 3D correlation methods to assignment of larger solid peptides and proteins.

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Comparison of the Stacking of Chlorophylls in Chlorosomes Versus Aggregates of Bacteriochlorophyll C and Chlorophyll A using 2-D MAS NMR Spectroscopy

Cited by 10 publications

References 7 publications

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

Ultrahigh Field MAS NMR Dipolar Correlation Spectroscopy of the Histidine Residues in Light-Harvesting Complex II from Photosynthetic Bacteria Reveals Partial Internal Charge Transfer in the B850/His Complex

2D and 3D¹⁵N−¹³C−¹³C NMR Chemical Shift Correlation Spectroscopy of Solids: Assignment of MAS Spectra of Peptides

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Comparison of the Stacking of Chlorophylls in Chlorosomes Versus Aggregates of Bacteriochlorophyll C and Chlorophyll A using 2-D MAS NMR Spectroscopy

Cited by 10 publications

References 7 publications

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

A Refined Model of the Chlorosomal Antennae of the Green Bacterium Chlorobium tepidum from Proton Chemical Shift Constraints Obtained with High-Field 2-D and 3-D MAS NMR Dipolar Correlation Spectroscopy

Ultrahigh Field MAS NMR Dipolar Correlation Spectroscopy of the Histidine Residues in Light-Harvesting Complex II from Photosynthetic Bacteria Reveals Partial Internal Charge Transfer in the B850/His Complex

2D and 3D15N−13C−13C NMR Chemical Shift Correlation Spectroscopy of Solids: Assignment of MAS Spectra of Peptides

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2D and 3D¹⁵N−¹³C−¹³C NMR Chemical Shift Correlation Spectroscopy of Solids: Assignment of MAS Spectra of Peptides