Practical aspects of Lee–Goldburg based CRAMPS techniques for high-resolution 1H NMR spectroscopy in solids: Implementation and applications

Coelho, Carlos; Rocha, João; Madhu, Perunthiruthy K.; Mafra, Luís

doi:10.1016/j.jmr.2008.07.019

Cited by 51 publications

(55 citation statements)

References 84 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The optimizations were carried out by acquiring 1D 1 H wPMLG3 þ magic-angle spinning (MAS) spectra on glycine through monitoring the splitting between α-protons lines (28). To optimize performance for 2D fashion, ν 1 and Δt were further examined in the indirect dimension of 2D 1 HfwPMLG3 þ g-1 HfwPMLG3 þ g homonuclear correlation spectra of the same sample (52). Optimum values were obtained using a pulse length Δt of 2.1 μs and rf amplitude (ν 1 ) of 78 kHz.…”

Section: Methodsmentioning

confidence: 99%

“…Optimum values were obtained using a pulse length Δt of 2.1 μs and rf amplitude (ν 1 ) of 78 kHz. In addition, the acquisition window τ w was set to 6.5 μs, slightly higher than the calibrated value, for compensation of the spectral quality loss caused by any mistuned wobble curve (52). The PMLG3 segment was composed of six rf pulses (Δt ¼ 2.1 μs) with a delay τ x of 0.1 μs (28) between two pulses to stabilize their phases, thus τ PMLG3 ¼ 13.2 μs.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Two ground state isoforms and a chromophore D -ring photoflip triggering extensive intramolecular changes in a canonical phytochrome

Song

Psakis

Lang

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

162

299

View full text Add to dashboard Cite

Phytochrome photoreceptors mediate light responses in plants and in many microorganisms. Here we report studies using 1 H-13 C magic-angle spinning NMR spectroscopy of the sensor module of cyanobacterial phytochrome Cph1. Two isoforms of the red-light absorbing Pr ground state are identified. Conclusive evidence that photoisomerization occurs at the C15-methine bridge leading to a β-facial disposition of the ring D is presented. In the far-red-light absorbing Pfr state, strong hydrogen-bonding interactions of the D-ring carbonyl group to Tyr-263 and of N24 to Asp-207 hold the chromophore in a tensed conformation. Signaling is triggered when Asp-207 is released from its salt bridge to Arg-472, probably inducing conformational changes in the tongue region. A second signal route is initiated by partner swapping of the B-ring propionate between Arg-254 and Arg-222.chromophore-protein interaction | signal transduction | solid-state NMR | photomorphogenesis P hytochrome was first demonstrated in plants as a red-lightdependent photoreceptor regulating numerous photomorphogenic processes (1, 2). Phytochromes are, however, also now known in photosynthetic prokaryotes including cyanobacteria (3, 4), nonphotosynthetic bacteria (5), and fungi (6). Generally, the phytochrome apoprotein binds an open-chain tetrapyrrole as a chromophore (7,8) to form the red-light absorbing Pr ground state (λ max ≈ 658 nm in case of cyanobacterial phytchrome Cph1 from Synechocystis 6803). Red light absorption photoactivates the molecule to form the photoactivated far-red-light absorbing Pfr state (λ max ≈ 702 nm for Cph1) via a series of intermediates (8-10). Photoactivation is thought to be initiated by a double bond isomerization of the chromophore (10, 11). Early NMR spectroscopic studies on proteolytic phytochrome fragments (12, 13) indicated that this isomerization occurs at the C15═C16 double bond (for numbering, see Fig. 1A), a geometrical change in line with vibrational spectroscopic investigations (14-16) and results from recent 13 C solid-state NMR (17, 18) in which the most significant changes during the light-triggered conversions are confined to rings C and D. Exact geometries of the chromophore in the Pr state have been resolved as periplanar ZZZssa configurations in bacteriophytochromes from Deinococcus radiodurans (19) and Rhodopseudomonas palustris (20) as well as in the more plant-phytochrome-like Cph1 from the cyanobacterium Synechocystis 6803 (21). On the other hand, the crystal structure of the unusual bacteriophytochrome PaBphP Pseudomonas aeruginosa (22) whose ground state is Pfr shows a ZZEssa conformation, consistent with the expected primary photochemistry at the C15═C16 double bond (Fig. 1 B vs. C). Very recently, however, Ulijasz et al. presented structural simulations based on liquid NMR data of a 20-kDa GAF (cGMP phosphodiesterase/ adenylyl cyclase/FhlA) domain fragment of "SyB-Cph1" phytochrome from the thermotolerant cyanobacterium Synechococcus OSB′ (23). Surprisingly, they concluded that photoisomerization occ...

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Two ground state isoforms and a chromophore D -ring photoflip triggering extensive intramolecular changes in a canonical phytochrome

Song

Psakis

Lang

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

162

299

View full text Add to dashboard Cite

show abstract

“…Setting up the LG condition has been described in detail previously, [31] while the LG-HETCOR-LG required the additional coordination between the LG cycles in the evolution period and the indirect spectral width and resolution. Thus, indirect spectral width must be set to the inverse of an even number of LG cycles.…”

Section: Setting Up Wise-lg and Lg-hetcor-lg Experimentsmentioning

confidence: 99%

“…The LG decoupling is particularly successful where inter-proton couplings are weakened by a process of partial averaging, for example in molecules with significant rotational freedom within crystalline lattices. [31] By contrast, carbon-proton systems subjected to rigorous motional restrictions or in the presence of intermediate time scale mobility, for example amino acid powders or membrane proteins, do not respond to the same degree and resolving 1 J CHcouplings is more challenging. In variants of the LG experiment, averaging is achieved by frequency excursions [32] or by variation in the phase of the frequency offset pulses.…”

Section: Introductionmentioning

confidence: 99%

Heteronuclear chemical shift correlation and J‐resolved MAS NMR spectroscopy of lipid membranes

Zorin

Ciesielski

Griffin

et al. 2010

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

Direct observation of J-couplings remains a challenge in high-resolution solid-state NMR. In some cases, it is possible to use Lee-Goldburg (LG) homonuclear decoupling during rare spin observation in MAS NMR correlation spectroscopy of lipid membranes to obtain J-resolved spectra in the direct dimension. In one simple implementation, a wide line separation-type (13)C-(1)H HETCOR can provide high-resolution (1)H/(13)C spectra, which are J-resolved in both dimensions. Coupling constants, (1)J(HC), obtained from (1)H doublets, can be compared with scaled (1)J(θ)(CH)-values obtained from the (13)C multiplets to assess the LG efficiency and scaling factor. The use of homonuclear decoupling during proton evolution, LG-HETCOR-LG, can provide J-values, at least in the rare spin dimension, and allows measurements in less mobile membrane environments. The LG-decoupled spectroscopic approach is demonstrated on pure dioleoylphosphatidylcholine (DOPC) membranes and used to investigate lipid mixtures of DOPC/cholesterol and DOPC/cholesterol/sphingomyelin.

show abstract

“…The preparation period was followed by the wPMLG sequence consisting of a train of pulses with narrow windows for direct acquisition of the signal, resulting in wPMLG-5. [10,13,34] The implementation of the wPMLG-5 pulse sequence on our spectrometer was first tested on glycine (Figure 3). The three peaks are well resolved, two coming from CH 2 and one from NH 2 groups.…”

Section: Resultsmentioning

confidence: 99%

wPMLG‐5 Spectroscopy of Self‐Aggregated BChl e in Natural Chlorosomes of Chlorobaculum Limnaeum

Miloslavina

Gupta

Tank

et al. 2014

Israel Journal of Chemistry

View full text Add to dashboard Cite

1H magic angle spinning (MAS) nuclear magnetic resonance (NMR), employing rapid spinning and the wPMLG‐5 pulse sequence, was used to explore the possibility for performing 1H solid state NMR of a light‐harvesting organelle, the chlorosome antenna of Chlorobaculum limnaeum. This natural antenna system is built from bacteriochlorophyll e (BChl e) molecules that are self‐assembled to form a supramolecular scaffold for in vivo harvesting of light. We present preliminary data on this chlorosome species and address the feasibility of performing wPMLG spectroscopy, in terms of high power irradiation on a fragile biological sample. In parallel, enhancing the 1H shift dispersion from the magnetic field can help to resolve signals from protons that resonate downfield. Different line narrowing mechanisms operating in parallel provide access to resolving selected 1H signals collected from the moderately sized and chemically diverse BChl e molecular motif in the chlorosome scaffold. These discoveries will be helpful for future studies of structural and functional characteristics of self‐assembled natural and artificial light‐harvesting molecules.

show abstract

Practical aspects of Lee–Goldburg based CRAMPS techniques for high-resolution 1H NMR spectroscopy in solids: Implementation and applications

Cited by 51 publications

References 84 publications

Two ground state isoforms and a chromophore D -ring photoflip triggering extensive intramolecular changes in a canonical phytochrome

Two ground state isoforms and a chromophore D -ring photoflip triggering extensive intramolecular changes in a canonical phytochrome

Heteronuclear chemical shift correlation and J‐resolved MAS NMR spectroscopy of lipid membranes

wPMLG‐5 Spectroscopy of Self‐Aggregated BChl e in Natural Chlorosomes of Chlorobaculum Limnaeum

Contact Info

Product

Resources

About