Secondary structural changes of proteins in fingernails of chronic fatigue syndrome patients from Fourier-transform infrared spectra

BackgroundGenerally, nails can be an index of health, with abnormalities sometimes found under diseased conditions. Fatigue is also supposed to affect the condition of nails. Possible differences in infrared (IR) spectra of nail plates of chronic fatigue syndrome (CFS) patients compared to healthy control subjects were investigated in this study.MethodsUsing an attenuated total reflection (ATR)–Fourier-transform infrared (FTIR) spectrophotometer, spectra in the region of 4000–600 cm–1 were obtained. The amide I region was then separated by Fourier deconvolution and curve fitting based on the Gauss and Lorentz formula and revealed differences in the secondary structural content of proteins compared to healthy donors.ResultsThe specific secondary structural pattern commonly observed in nails of male and female CFS patients in the absence and presence of medication indicated a decreased α-helix content and increased β-sheet content, suggesting reduced levels of normal elements of the nail plate.ConclusionsThis provides the first evidence of alterations in the fingernails of CFS patients which could be detected by IR spectroscopy. Possible explanations for the alterations will be discussed.