– dipolar-assisted rotational resonance in magic-angle spinning NMR

Takegoshi, K.; Nakamura, Shinji; Terao, Takehiko

doi:10.1016/s0009-2614(01)00791-6

Cited by 972 publications

(1,076 citation statements)

References 13 publications

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“…Strong crosspeaks in the 2D fpRFDR spectra connect 13 C NMR lines of directly-bonded carbon sites. In 2D radiofrequency-assisted diffusion (RAD) measurements, exchange periods ranging from 500 ms to 1000 ms were used, during which an rf field amplitude equal to the MAS frequency was applied to protons (61,62). With long exchange periods, strong crosspeaks in 2D RAD spectra connect all 13 C NMR lines arising from a single labeled residue or from pairs of labeled residues that occur sequentially (i.e., consecutively in the amylin sequence).…”

Section: Solid State Nmrmentioning

confidence: 99%

Peptide Conformation and Supramolecular Organization in Amylin Fibrils: Constraints from Solid-State NMR

et al. 2007

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The 37-residue amylin peptide, also known as islet amyloid polypeptide, forms fibrils that are the main peptide or protein component of amyloid that develops in the pancreas of type 2 diabetes patients. Amylin also readily forms amyloid fibrils in vitro that are highly polymorphic under typical experimental conditions. We describe a protocol for the preparation of synthetic amylin fibrils that exhibit a single predominant morphology, which we call a striated ribbon, in electron microscope and atomic force microscope images. Solid state nuclear magnetic resonance (NMR) measurements on a series of isotopically labeled samples indicate a single molecular structure within the striated ribbons. We use scanning transmission electron microscopy and several types of one-dimensional and two-dimensional solid state NMR techniques to obtain constraints on the peptide conformation and supramolecular structure in these amylin fibrils, and derive molecular structural models that are consistent with the experimental data. The basic structural unit in amylin striated ribbons, which we call the protofilament, contains four-layers of parallel β-sheets, formed by two symmetric layers of amylin molecules. The molecular structure of amylin protofilaments in striated ribbons closely resembles the protofilament in amyloid fibrils with similar morphology formed by the 40-residue β-amyloid peptide that is associated with Alzheimer's disease. Keywordsislet amyloid polypeptide; type 2 diabetes; amyloid fibril structure; electron microscopy; atomic force microscopy Amylin, also called islet amyloid polypeptide or IAPP, is a 37-residue peptide that is cosecreted with insulin by the β-cells of pancreas. The normal biological effects of amylin secretion include inhibition of glucagon secretion and reduction of the rate of gastric emptying, effects that contribute to the maintenance of postprandial glucose homeostasis (1). Amylin is the major peptide or protein component of the islet amyloid found in the pancreas of approximately 90% of type 2 (or non-insulin-dependent) diabetes patients (2,3). Fibrillar amylin has been shown * Corresponding author: Dr. Robert Tycko, National Institutes of Health, Building 5, Room 112, Bethesda, MD 20892-0520. phone 301-402-8272. fax 301-496-0825. e-mail robertty@mail.nih.gov.Supporting Information Available HPLC chromatograms from the purification of both reduced and oxidized amylin by reverse-phase chromatography ( Figure S1); FPLC chromatograms from the purification of both human and rodent amylin by size-exclusion chromatography ( Figure S2); 1D 13 C spectra of amylin fibrils with various isotopic labeling patterns, in lyophilized and rehydrated conditions ( Figures S3-S5); Table of 13 C NMR chemical shifts in amylin fibrils, TALOS predictions of backbone torsion angles based on these shifts, and torsion angles determined from 15 N fpRFDR-CT measurements (Table S1). This material is freely available on the World Wide Web at http://www.acs.org. to be toxic to cultured β-cells (4), and has been propo...

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Section: Solid State Nmrmentioning

confidence: 99%

Peptide Conformation and Supramolecular Organization in Amylin Fibrils: Constraints from Solid-State NMR

et al. 2007

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“…19 Once the secondary structure is known, the 3D fold of the protein can be obtained by measuring inter-residue 13 C-13 C distances using 2D or 3D correlation experiments with long mixing times. 20,21 This full-structure determination approach has been applied to a human a-defensin, HNP-1. 22,23 The monomer 3D structure forms the basis for determining the oligomeric structure of membrane proteins.…”

Section: Solid-state Nmr Techniques For Studying Protein-membrane Intmentioning

confidence: 99%

Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR

Hong¹,

Su²

2011

Protein Science

130

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Many membrane peptides and protein domains contain functionally important cationic Arg and Lys residues, whose insertion into the hydrophobic interior of the lipid bilayer encounters significant energy barriers. To understand how these cationic molecules overcome the free energy barrier to insert into the lipid membrane, we have used solid-state NMR spectroscopy to determine the membrane-bound topology of these peptides. A versatile array of solid-state NMR experiments now readily yields the conformation, dynamics, orientation, depth of insertion, and site-specific protein-lipid interactions of these molecules. We summarize key findings of several Arg-rich membrane peptides, including b-sheet antimicrobial peptides, unstructured cell-penetrating peptides, and the voltage-sensing helix of voltage-gated potassium channels. Our results indicate the central role of guanidinium-phosphate and guanidinium-water interactions in dictating the structural topology of these cationic molecules in the lipid membrane, which in turn account for the mechanisms of this functionally diverse class of membrane peptides.

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“…These requirements in some way have limited its diffusion. However, it has been demonstrate 49 that it is possibile to identify the supramolecular conformation of fibrils directly from symmetry-induced resonance patterns in 2D heteronuclear 15 N-13 C OC NCO and 15 N-13 C OC NCA (superscript OC designates experiments 50 designed using optimal control theory) correlation and homonuclear 13 C - 13 Cα DARR 51 correlation SSNMR spectra for a single 13 C, 15 N-labeled hIAPP20-29 (SNNFGAILSS) decapeptide from the human islet amyloid polypeptide (hIAPP), which is believed to form the fibrillation core domain of fibrils in the pancreas of type 2 diabetes patients. Again, several types of oneand two-dimensional SSNMR techniques have been used to obtain constraints on the peptide conformation and supramolecular structure in amylin fibrils, a 37-residue peptide also called islet amyloid polypeptide or IAPP, and to derive molecular structural models that are consistent with the experimental data.…”

Section: Distances and Constrains Determined By Solid-state Nmrmentioning

confidence: 99%

Solid‐State NMR Studies on Supramolecular Chemistry

Chierotti

Gobetto

2012

Supramolecular Chemistry

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Solid‐state NMR (SSNMR) methods provide new insights in the investigation of the structure and dynamics of condensed phases. Advances in commercial solid‐state hardware and the developments of new pulse sequences have been of paramount importance for overcoming the earlier resolution problems and yield spectra sensitive to intra‐ and intermolecular hydrogen‐bonding and π–π interactions. This chapter aims to provide an overview of the recent development of the technique for the study of the structure and dynamics of supramolecular systems paying particular attention to the role of the weak interactions such as hydrogen bonds through NMR chemical shift as well as the through‐space dipolar coupling SSNMR investigations.

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– dipolar-assisted rotational resonance in magic-angle spinning NMR

Cited by 972 publications

References 13 publications

Peptide Conformation and Supramolecular Organization in Amylin Fibrils: Constraints from Solid-State NMR

Peptide Conformation and Supramolecular Organization in Amylin Fibrils: Constraints from Solid-State NMR

Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR

Solid‐State NMR Studies on Supramolecular Chemistry

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