The influence of putrescine on the structure, enzyme activity and stability of α-chymotrypsin

Abstract

Information on protein stability is essential to study protein structure, activity, and interactions with ligands. The interaction of putrescine with α-chymotrypsin (α-Chy) was investigated by using different types of spectroscopic techniques in an aqueous medium at two temperatures (25 and 35 °C), in combination with a molecular docking study and molecular dynamics simulation. Fluorescence measurements showed that the observed quenching was a dynamic one. The intrinsic fluorescence of α-chymotrypsin was decreased in the presence of putrescine due to the excited-state proton transfer. Additionally, circular dichroism results revealed that putrescine binding had no dramatic influence on the α-chymotrypsin structure. Molecular docking also indicated that the hydrogen bonds interactions were dominant in the binding site.