Two-Dimensional terahertz correlation spectroscopic study on the conformation change of protein induced by pH

In this work, the terahertz (THz) absorption spectra of a typical protein BSA (Bovine Serum Albumin) in aqueous solution were measured under different pH conditions. The temporal changes in the absorption spectra were analyzed using the two-dimensional correlation spectroscopy (2DCOS). By comparing the cross peaks corresponding to the different pH values, it can be obtained that the conformation is related to the pH condition. The results provide a new approach to analyze the conformation change process of protein.