Theoretical study of two-photon circular dichroism on molecular structures simulating aromatic amino acid residues in proteins with secondary structures

Abstract

Herein, we report on the calculation and the comparative analysis of the theoretical two-photon circular dichroism (TPCD) spectra of L-histidine (His), L-phenylalanine (Phe), and L-tyrosine (Tyr) simulating residues in proteins with secondary structures (α-helix, β-strand and random coil), down to the far-UV region (FUV). This work exposes unique signatures in the FUV for each conformer in each configuration. The outcomes of this research show how FUV-TPCD can be used to study peptide and protein structures in a region never evaluated before but packed with important structural information.