Effect of High Blood Cortisol Concentration on the Spectroscopically Determined Secondary Structure of Proteins and Lipid Balance on the Example of Elite Women Volleyball Players

Cortisol is a stress hormone plays a crucial role in the balance between phospholipids and lipids level. In consequence, it affects the secondary structure of proteins. Currently cortisol concentration in plasma is determined by biochemical analysis. A new, optical method to estimate stress level is proposed in this work. Infrared and Raman spectroscopies were used to determine quantitative and qualitative changes in the lipids and proteins fraction in function of cortisol concentration in 49 samples of plasma collected from volleyball players at various stages of preparation for the competition. With the cortisol level increase, a decrease of structures related to PO2- phospholipids groups and amides III, II and I bonds was noticed in the transmission spectra. Changes in the secondary structure of protein were indicated as a frequency shift of α-helix and β-sheet vibrations observed in Raman spectra and second derivative of transmission spectra. Pearson correlation test presented positive correlations between phospholipids and proteins level and between cortisol concentration and phospholipids in transmittance spectra. Negative correlations between cortisol concentration and proteins and phospholipids level was observed in the Raman spectra. Both optical techniques are considered to become effective tools for estimating the concentration of cortisol in the plasma.