Infrared and confocal Raman spectroscopy to differentiate changes in the protein secondary structure in normal and abnormal thyroid tissues

Abstract

Thirty thyroid samples of normal and abnormal tissues were analyzed by infrared and confocal Raman Spectroscopy. We studied the Amide I (1,720–1,580 cm−1) spectral region in order to determine different components of the proteins' secondary structure in the samples. Peak positions of the Amide I bands were determined using the second derivative and Fourier self‐deconvolution of infrared and Raman spectra. We obtained band areas corresponding to β‐turn, 310‐helix, α‐helix, β‐sheet, β‐turns, and side chains for the infrared and confocal Raman spectra by Gaussian fitting. Using the second derivative of the infrared and Raman spectra, we demonstrated the consistency of the vibrational assignments because compounds of low symmetry without an inversion center present coincident bands that differ only in intensity; hence, the infrared procedures to identify and assign the bands of the proteins' secondary structure in the Raman spectra are valid. The results obtained are supported by vibrational theory and indicate that infrared and confocal Raman spectroscopy are important, useful, and fast tools to identify changes in the proteins' secondary structure in normal tissues, goiter, and follicular and papillary thyroid carcinomas.

Radial variation in biochemical composition of the bovine caudal intervertebral disc

“…57,58 In biological tissues, amide bands have been primarily used to study age-and disease-related alterations in protein secondary structure and conformation. 57,59,60 The peak at~1455 cm −1 corresponds to deformation vibrations of CH 2 and CH 3 amino acid side chains and lipids. 26 It should be noted that Raman vibrations have been related to more T A B L E 1 NP and AF values from differential scanning calorimetry than one amino acid or chemical group, making it difficult to identify differences in the fingerprint region.…”

“…Bands with a peak at 1252 and 1661 cm −1 have been associated with amide III and amide I, respectively, where amide I mainly reflects the C=O stretching vibration and the amide III band has contributions from several chemical bonds . In biological tissues, amide bands have been primarily used to study age‐ and disease‐related alterations in protein secondary structure and conformation . The peak at ~1455 cm −1 corresponds to deformation vibrations of CH 2 and CH 3 amino acid side chains and lipids .…”

Mutation Spectrum in TPO Gene of Bangladeshi Patients with Thyroid Dyshormonogenesis and Analysis of the Effects of Different Mutations on the Structural Features and Functions of TPO Protein through In Silico Approach

“…Such compositional analysis in various cellular conditions has become very popular for characterizing the biochemical changes in various disease conditions and also for the study on characterizing the spectrum of various hormones such as corticosteroids [70–72]. The study by Claudio et al analyzed the molecular vibrational spectrum of thyroid tissues from normal and disease conditions which could ultimately represent the characteristics of secondary structures of proteins [73]. Although use of IR and Raman spectroscopy could offer more insights into the physiological conditions of TDH patients carrying mutations in the TPO gene, the present study was not subjected to such approaches because we did not have such facilities.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Tellez Soto used IR absorption and confocal Raman spectroscopy to differentiate changes in protein secondary structure in normal and abnormal thyroid tissues. The results obtained were supported by vibrational analysis and indicate that IR and confocal Raman spectroscopy are important, useful, and fast tools to identify changes in the proteins' secondary structure in normal tissues, goiter, and follicular and papillary thyroid carcinomas . Wang et al implemented hyper‐spectral Raman imaging to correlate chemical substitution and crystallinity in biogenic hydroxyapatite for dentin and enamel in normal and hypoplastic human teeth .…”