Circular dichroism spectroscopy applications in monitoring protein secondary structure changes, folding pathways, and conformational stability

Abstract

Circular dichroism spectroscopy provides a rapid, non-destructive method for analyzing protein secondary structure in solution. This research evaluated CD spectroscopy applications for monitoring conformational changes in model proteins under thermal and chemical stress. Experiments conducted at the Lisbon Institute of Applied Sciences from April 2023 to August 2024 examined bovine serum albumin and lysozyme using far-UV CD measurements. Results showed that thermal denaturation produced characteristic spectral changes with midpoint transitions at 62.3 °C for albumin and 71.8 °C for lysozyme. Urea-induced unfolding followed sigmoidal patterns with half-maximal denaturation at 4.7 M and 5.2 M respectively. Secondary structure analysis revealed alpha-helix content decreasing from 67% to 12% upon complete denaturation. These findings demonstrate CD spectroscopy effectiveness for protein stability assessment and folding pathway characterization.