Tracking Transitions in Spider Wrapping Silk Conformation and Dynamics by (19)F-NMR Spectroscopy.
Biochemistry. 2016 May 6;
Authors: Sarker M, Orrell KE, Xu L, Tremblay ML, Bak JJ, Liu XQ, Rainey JK
Abstract
Aciniform silk protein (AcSp1) is the primary component of wrapping silk, the toughest of the spider silks due to combined high tensile strength and extensibility. Argiope trifasciata AcSp1 contains a core repetitive domain with at least 14 homogeneous 200-amino acid units ("W" units). Upon fibrillogenesis, AcSp1 converts from an ?-helix-rich soluble state to a mixed ?-helical/?-sheet conformation. Solution-state nuclear magnetic resonance (NMR) spectroscopy allowed demonstration of variable local stability within the W-unit, but comprehensive characterization was confounded by spectral overlap, exacerbated by decreased chemical shift dispersion upon denaturation. Here, (19)F-NMR spectroscopy, in the context of a single W-unit (W1), is applied to track changes in structure and dynamics. Four strategic positions in the W-unit were mutated to tryptophan and biosynthetically labeled with 5-fluorotryptophan (5F-Trp). Simulated annealing-based structure calculations implied that these substitutions should be tolerated while circular dichroism (CD) spectroscopy and (1)H-(15)N chemical shift displacements indicated minimal structural perturbation in W1 mutants. Fiber formation by W2 concatemers containing 5F-Trp substitutions in both W-units demonstrated retention of functionality, a somewhat surprising finding in light of sequence conservation between species. Each 5F-Trp-labeled W1 exhibited a unique (19)F chemical shift, linewidth, longitudinal relaxation time constant (T1), and solvent isotope shift. Perturbation to (19)F chemical shift and nuclear spin relaxation parameters reflected changes in conformation and dynamics at each 5F-Trp site upon addition of urea and dodecylphosphocholine (DPC). (19)F-NMR spectroscopy allowed unambiguous localized tracking throughout titration with each perturbant, demonstrating distinct behavior for each perturbant not previously revealed by heteronuclear NMR experiments.
PMID: 27153372 [PubMed - as supplied by publisher]
[NMR paper] Elucidating proline dynamics in spider dragline silk fibre using 2H-13C HETCOR MAS NMR.
Elucidating proline dynamics in spider dragline silk fibre using 2H-13C HETCOR MAS NMR.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.rsc.org-images-entities-char_z_RSClogo.gif Related Articles Elucidating proline dynamics in spider dragline silk fibre using 2H-13C HETCOR MAS NMR.
Chem Commun (Camb). 2014 May 14;50(37):4856-9
Authors: Shi X, Yarger JL, Holland GP
Abstract
(2)H-(13)C HETCOR MAS NMR is performed on (2)H/(13)C/(15)N-Pro enriched A. aurantia dragline silk. Proline dynamics are extracted...
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04-22-2015 03:33 PM
Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk - (e) Science News
Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk - (e) Science News
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Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk
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Jan Rainey's group at Dalhousie University used nuclear magnetic resonance (NMR) spectroscopy to analyze the structure of AcSp1's repeat sequence at very high resolution, producing one of the first spider silk repeat...
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02-12-2015 06:10 AM
Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk - Nanowerk
Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk - Nanowerk
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Nanowerk
<img alt="" height="1" width="1">
Arachnid Rapunzel: Researchers spin spider silk proteins into artificial silk
Nanowerk
Jan Rainey's group at Dalhousie University used nuclear magnetic resonance (NMR) spectroscopy to analyze the structure of AcSp1's repeat sequence at very high resolution, producing one of the first spider silk repeat unit structure sequences...
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02-11-2015 12:26 AM
[NMR paper] Molecular Dynamics of Spider Dragline Silk Fiber Investigated by 2H MAS NMR.
Molecular Dynamics of Spider Dragline Silk Fiber Investigated by 2H MAS NMR.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-pubmed-acspubs.jpg Related Articles Molecular Dynamics of Spider Dragline Silk Fiber Investigated by 2H MAS NMR.
Biomacromolecules. 2015 Jan 25;
Authors: Shi X, Holland GP, Yarger JL
Abstract
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Exploring the Backbone Dynamics of Native Spider Silk Proteins in Black Widow Silk Glands with Solution-state NMR Spectroscopy
Exploring the Backbone Dynamics of Native Spider Silk Proteins in Black Widow Silk Glands with Solution-state NMR Spectroscopy
Publication date: Available online 13 June 2014
Source:Polymer</br>
Author(s): Dian Xu , Jeffery L. Yarger , Gregory P. Holland</br>
Spider dragline silk is an outstanding biopolymer with a strength that exceeds steel by weight and a toughness greater than high-performance fibers like Kevlar. For this reason, understanding how a spider converts the gel-like, aqueous protein spinning dope within the major ampullate (MA) gland into a super...
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06-14-2014 12:53 AM
[NMR paper] Amino Acid Analysis of spider dragline silk using (1)H NMR.
Amino Acid Analysis of spider dragline silk using (1)H NMR.
Related Articles Amino Acid Analysis of spider dragline silk using (1)H NMR.
Anal Biochem. 2013 May 30;
Authors: Shi X, Holland GP, Yarger JL
Abstract
The amino acid composition of N. clavipes dragline silk fiber is determined by conducting (1)H Nuclear Magnetic Resonance (NMR) spectroscopy experiments on acid hydrolyzed material. N. clavipes dragline silk was found to consist of 43.0±0.6% Gly, 29.3±0.2% Ala, 9.1±0.1% Glx, 4.0±0.1% Leu, 3.3±0.1% Tyr, 3.4 ±0.2% Ser, 2.7±0.1%...
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06-04-2013 06:31 PM
[NMR paper] Probing site-specific (13)C/ (15)N-isotope enrichment of spider silk with liquid-state NMR spectroscopy.
Probing site-specific (13)C/ (15)N-isotope enrichment of spider silk with liquid-state NMR spectroscopy.
Probing site-specific (13)C/ (15)N-isotope enrichment of spider silk with liquid-state NMR spectroscopy.
Anal Bioanal Chem. 2013 Feb 26;
Authors: Shi X, Yarger JL, Holland GP
Abstract
Solid-state nuclear magnetic resonance (NMR) has been extensively used to elucidate spider silk protein structure and dynamics. In many of these studies, site-specific isotope enrichment is critical for designing particular NMR methods...
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02-26-2013 06:35 PM
[NMR paper] Effect of pH and copper(II) on the conformation transitions of silk fibroin based on
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Related Articles Effect of pH and copper(II) on the conformation transitions of silk fibroin based on EPR, NMR, and Raman spectroscopy.
Biochemistry. 2004 Sep 28;43(38):11932-41
Authors: Zong XH, Zhou P, Shao ZZ, Chen SM, Chen X, Hu BW, Deng F, Yao WH
Much attention has been paid to the natural mechanism of silkworm spinning due to the impressive mechanical properties of the natural fibers. Our results in the present work show...
Tracking Transitions in Spider Wrapping Silk Conformation and Dynamics by (19)F-NMR Spectroscopy.
Linear Mode
