Conformational differences in protein disulfide linkages between normal hair and hair from subjects with trichothiodystrophy: a quantitative analysis by Raman microspectroscopy.
Raman spectra of normal hair shafts and hair shafts from patients exhibiting trichothiodystrophy (TTD) were obtained using line focus laser illumination. Because hair from TTD patients has a significant decrease in the content of the sulfur-containing amino acids in comparison to normal hair, the 550-500 cm(-1) disulfide stretching mode region of the Raman spectrum was examined in detail. A quantitative spectral analysis demonstrates significant increases in the two energetically less favored gauche-gauche-trans (g-g-t) and trans-gauche-trans (t-g-t) forms. These observations suggest that the increased amounts of these less stable disulfide conformers are contributing factors to or associated with the hair brittleness observed for this congenital disorder. Structure-spectra correlations for the three dominant disulfide conformers are confirmed by quantum chemical calculations using modern density functional theory (DFT).
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
S
S
Schlücker
C
C
Liang
K R
KR
Strehle
J J
JJ
DiGiovanna
K H
KH
Kraemer
I W
IW
Levin
D001704:Biopolymers / Q000737:chemistry; D004260:DNA Repair / Q000235:genetics; D004220:Disulfides / Q000737:chemistry; D006197:Hair / Q000737:chemistry* / Q000473:pathology; D006201:Hair Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
D001704:Biopolymers; D004220:Disulfides; D011506:Proteins