Structure and dynamics of aromatic residues in spider silk: 2D carbon correlation NMR of dragline fibers

Thomas Izdebski, Paul Akhenblit, Janelle E. Jenkins, Jeffery Yarger, Gregory P. Holland

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The structure of aromatic residues in spider silk has remained relatively uncharacterized. This is primarily due to the relatively low abundance of aromatic residues in dragline spider silk. NMR characterization has been further hindered by the inability to 13C-isotopically enrich these amino acids in the silk effectively. In the present contribution, it is shown that feeding spiders an aqueous solution of [U-13C/15N]-L- phenylalanine 13C-enriches Tyr to a level of 20-30% in dragline spider silk. This enables the collection of 2D through-bond 13C double quantum/single quantum (DQ/SQ) correlation spectra with the refocused INADEQUATE solid-state NMR pulse sequence. These 2D spectra provide the complete unambiguous assignment of the Tyr resonances in dragline silks from two spider species: N. clavipes and A. aurantia. Additionally, weak resonances are detected for Phe in A. aurantia dragline silk that is present at levels <1%. The conformation dependence of the Cα, Cβ, and carbonyl chemical shifts show that Tyr and Phe present in the GGX and GPGXX motifs in the spider silk proteins MaSp1 and MaSp2 are in disordered helical structures and not incorporated in the β-sheet domains.

Original languageEnglish (US)
Pages (from-to)168-174
Number of pages7
JournalBiomacromolecules
Volume11
Issue number1
DOIs
StatePublished - Jan 11 2010

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Silk
Carbon
Nuclear magnetic resonance
Fibers
Chemical shift
Phenylalanine
Conformations
Amino acids
Proteins
Amino Acids

ASJC Scopus subject areas

  • Bioengineering
  • Materials Chemistry
  • Polymers and Plastics
  • Biomaterials

Cite this

Structure and dynamics of aromatic residues in spider silk : 2D carbon correlation NMR of dragline fibers. / Izdebski, Thomas; Akhenblit, Paul; Jenkins, Janelle E.; Yarger, Jeffery; Holland, Gregory P.

In: Biomacromolecules, Vol. 11, No. 1, 11.01.2010, p. 168-174.

Research output: Contribution to journalArticle

Izdebski, Thomas ; Akhenblit, Paul ; Jenkins, Janelle E. ; Yarger, Jeffery ; Holland, Gregory P. / Structure and dynamics of aromatic residues in spider silk : 2D carbon correlation NMR of dragline fibers. In: Biomacromolecules. 2010 ; Vol. 11, No. 1. pp. 168-174.
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