The Application of “Excitation Sculpting” in the Construction of Selective One-Dimensional Homonuclear Coherence-Transfer Experiments

“…11,12,21,45 The ␤-turn values can be either ϩ⌬J or Ϫ⌬J. 21,32,45 For the 12-mer at pH 7.4, the most significant finding is the presence of Ͼ1 Hz (ϩ) ⌬J for F1, G3, K4, N5, V6, N7, C8, T9, S10, and G11. Again, as observed for the ⌬␦H ␣ values, the contiguous -NCTS-region exhibits significant directional deviations in J-couplings from random coil values.…”

Section: Nmr Spectroscopymentioning

confidence: 94%

“…To confirm these findings, we estimated the presence or absence of solvent exchange between H 2 O and the backbone amide protons in the FPGKNVNCTSGE sequence, using PFG-NOESY experiments (150 ms mixing time). 11,12,32 The exchange regime that we can measure is on the NMR timescale (milliseconds to seconds); any exchange processes that occur on a slower timescale will not be observed. As shown in Figure 5, we observe solvent exchange for all ␣-NH protons, indicating that there is proton exchange occurring at these sites.…”

Section: Thus the Absence Of Sequential D Nn(iiϩ1) Noes In The Lustmentioning

confidence: 99%

“…11,12 Proton scalar coupling assignments were obtained using "excitation sculpting" 31 two-dimensional (2D) PFG-"clean" total correlated spectroscopy (TOCSY) experiments. 11,12,32 Proton sequential assignments and NOEs were obtained using (z-axis)-PFG-NOE spectroscopy (NOESY) and rotating frame NOESY (ROESY) experiments, 11,12,31 using a range of mixing times from 50 to 200 ms; spectra were jointly analyzed to exclude artifactual NOEs arising from spin diffusion. 19 3 J NH-CH␣ values were determined using z-PFG phase enhanced (P.E.)…”

Section: Nmr Experimentsmentioning

confidence: 99%

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Model peptide studies of sequence regions in the elastomeric biomineralization protein, Lustrin A. I. The C‐domain consensus—PG—, —NVNCT—motif

et al. 2002

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The lustrin superfamily represents a unique group of biomineralization proteins localized between layered aragonite mineral plates (i.e., nacre layer) in mollusk shell. Recent atomic force microscopy (AFM) pulling studies have demonstrated that the lustrin-containing organic nacre layer in the abalone, Haliotis rufescens, exhibits a typical sawtooth force-extension curve with hysteretic recovery. This force extension behavior is reminiscent of reversible unfolding and refolding in elastomeric proteins such as titin and tenascin. Since secondary structure plays an important role in force-induced protein unfolding and refolding, the question is, What secondary structure(s) exist within the major domains of Lustrin A? Using a model peptide (FPGKNVNCTSGE) representing the 12-residue consensus sequence found near the N-termini of the first eight cysteine-rich domains (C-domains) within the Lustrin A protein, we employed CD, NMR spectroscopy, and simulated annealing/minimization to determine the secondary structure preferences for this sequence. At pH 7.4, we find that the 12-mer sequence adopts a loop conformation, consisting of a "bend" or "turn" involving residues G3-K4 and N7-C8-T9, with extended conformations arising at F1-G3; K4-V6; T9-S10-G11 in the sequence. Minor pH-dependent conformational effects were noted for this peptide; however, there is no evidence for a salt-bridge interaction between the K4 and E12 side chains. The presence of a loop conformation within the highly conserved -PG-, -NVNCT- sequence of C1-C8 domains may have important structural and mechanistic implications for the Lustrin A protein with regard to elastic behavior.

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“…This applies to NOE and TOCSY methods, 2 -4 and also to many related techniques such as SELCOSY, SELRELAY, SELTOCSY, 5 TOCSY-ROESY, ROESY-TOCSY, 6 COSY-NOESY, COSY-ROESY, TOCSY-NOESY and TOCSY-ROESY. 7 The selective population transfer (SPT) method 4,8,9 has long been known as a valuable mean of determining the Ł Correspondence to: Jun Uzawa, Plant Science Center, Riken (Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.…”

Section: Introductionmentioning

confidence: 96%

A new selective population transfer experiment using a double pulsed field gradient spin‐echo

Uzawa

2004

Magnetic Reson in Chemistry

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A new pulse sequence is proposed for the determination of scalar coupling correlation in small- and medium-sized organic compounds. The method uses a combination of the double pulsed field gradient spin-echo (DPFGSE) and the selective population transfer (SPT) techniques and is shown to be useful in the analysis of complex spectra with many overlapped signals. The usefulness of this method in the structural elucidation of natural substances is demonstrated using strychnine and digitoxin as examples.

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The Application of “Excitation Sculpting” in the Construction of Selective One-Dimensional Homonuclear Coherence-Transfer Experiments

Cited by 38 publications

References 5 publications

Extending the limits of the selective 1D NOESY experiment with an improved selective TOCSY edited preparation function

Extending the limits of the selective 1D NOESY experiment with an improved selective TOCSY edited preparation function

Model peptide studies of sequence regions in the elastomeric biomineralization protein, Lustrin A. I. The C‐domain consensus—PG—, —NVNCT—motif

A new selective population transfer experiment using a double pulsed field gradient spin‐echo

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