Dynamic Detection of Thiol Oxidation/Reduction Status During the Conversion of Cysteine/Cystine

The thiol redox state (TRS) plays a key role in evaluating essential biochemical processes, such as evaluating intracellular enzymatic activity. The TRS, characterized by the kinetic parameters of the thiol (- SH)/disulfide bond (-SS-) redox process, was measured by the Fourier-transform Raman spectroscopy (FT-Raman) and the terahertz time-domain spectroscopy (THz-TDS) in this study. A good correlation was observed between the disulfide concentration in samples and the intensities of the disulfide characteristic peaks in the FT-Raman and THz-TDS spectra. And the linear regression analysis correlation coefficients had values of 92.2% for FT-Raman-derived data and 95.4% for THz-TDS-derived data. The dynamic response of the cysteine/cystine experimental spectrum and characteristic peaks were analyzed by solid-state density functional theory. It can be found that both Raman and terahertz vibrational spectroscopy techniques can quantitatively analyze the ratio of cysteine/cystine. This provides a new method for the biological analysis of sulfur-containing amino acids and other related mixtures in basic science. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study utilized FT-Raman and THz-TDS spectroscopy techniques to measure the TRS, showing a good correlation between disulfide concentration and characteristic peak intensities, with correlation coefficients of 92.2% and 95.4% for FT-Raman and THz-TDS data, respectively. Solid-state density functional theory analysis revealed that both Raman and terahertz vibrational spectroscopy techniques can quantitatively analyze the ratio of cysteine/cystine, providing a new method for biological analysis of sulfur-containing amino acids and related mixtures in basic science.