Morphology and molecular mobility of fibrous hard a-keratins by 1H, 13C, and129Xe NMR

Maria Baias, Dan E. Demco, Daniel Istrate, Crisan Popescu, Bernhard Blümich, Martin Möller

Research output: Contribution to journalArticle

Abstract

The morphology and molecular mobility changes of the side chains for hard α-keratin due to oxidative and reductive/oxidative treatments for temperatures around the DSC denaturation peak were investigated by 1H, 13C, and 129Xe NMR spectroscopy and 1H spin diffusion. Proton wide-line spectra were used to obtain the phase composition (rigid, interface, and amorphous fractions) and molecular dynamics of each phase. Proton spin diffusion experiments using a double-quantum filter and initial rate approximation were employed to obtain the dependence of the rigid domain sizes on chemical treatments and denaturation temperatures. A drastic reduction in the rigid domain thickness takes place for the reductive/oxidative treatment. The keratin mobility gradient in the interfacial region at different denaturation temperatures was measured for hard α-keratin from 1H spin diffusion data. 13C CPMAS spectra were used to provide a detailed examination of the effects of the chemical treatments especially on the disulfide bonds. Thermally polarized 129Xe spectra suggest the existence of voids in the hard α-keratin induced by the reductive and oxidative treatment. The surface of the hard α-keratin fiber surface is probed by the laser hyperpolarized 129Xe. A qualitative model describing the changes induced in hard α-keratin protein by chemical transformation was developed and could be correlated with the changes in domain thickness, phase composition, and molecular dynamics.

Original languageEnglish (US)
Pages (from-to)12136-12147
Number of pages12
JournalJournal of Physical Chemistry B
Volume113
Issue number35
DOIs
StatePublished - Sep 3 2009

Fingerprint

keratins
Keratin
Keratins
Nuclear magnetic resonance
nuclear magnetic resonance
Denaturation
biopolymer denaturation
Phase composition
Molecular dynamics
Protons
molecular dynamics
protons
disulfides
Disulfides
Temperature
Nuclear magnetic resonance spectroscopy
temperature
line spectra
voids
examination

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

Morphology and molecular mobility of fibrous hard a-keratins by 1H, 13C, and129Xe NMR. / Baias, Maria; Demco, Dan E.; Istrate, Daniel; Popescu, Crisan; Blümich, Bernhard; Möller, Martin.

In: Journal of Physical Chemistry B, Vol. 113, No. 35, 03.09.2009, p. 12136-12147.

Research output: Contribution to journalArticle

Baias, M, Demco, DE, Istrate, D, Popescu, C, Blümich, B & Möller, M 2009, 'Morphology and molecular mobility of fibrous hard a-keratins by 1H, 13C, and129Xe NMR', Journal of Physical Chemistry B, vol. 113, no. 35, pp. 12136-12147. https://doi.org/10.1021/jp904484r
Baias, Maria ; Demco, Dan E. ; Istrate, Daniel ; Popescu, Crisan ; Blümich, Bernhard ; Möller, Martin. / Morphology and molecular mobility of fibrous hard a-keratins by 1H, 13C, and129Xe NMR. In: Journal of Physical Chemistry B. 2009 ; Vol. 113, No. 35. pp. 12136-12147.
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