Related Experiment Video
Updated: Feb 25, 2026

Author Spotlight: A Computational Approach to Decipher Amino Acid Preferences in Multispecific Protein-Protein Interactions
Published on: January 26, 2024
Probing the binding properties of dicyandiamide with pepsin by spectroscopy and docking methods
Yuanyuan Yue1, Shufang Zhao1, Jianming Liu1
1Henan Key Laboratory of Green Chemicals Media and Reactions, Ministry of Education, Key Laboratory of Green Chemical Media and Reactions, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering Institution, Henan Normal University, 453007, Xinxiang, China.
Abstract:
Dicyandiamide (DCD), considered to be a nitrification inhibitor, poses threat to human's health with exposure from milk, infant formula and other food products. In this work, DCD was investigated for its binding reaction with pepsin using spectroscopy and docking methods. Fluorescence experiments indicated DCD quenched the fluorescence of pepsin through a static process. Thermodynamic analysis of the binding data (ΔH0 = -21.72 kJ mol-1 and ΔS0 = 17.61 J mol-1 K-1) suggested the involvement of hydrophobic and hydrogen bonding in the complex formation. The pepsin interacted with DCD at a hydrophobic cavity, leading to a conformational changes in the pepsin, as revealed from UV-vis absorption, Fourier transform infrared, the time-resolved fluorescence, three-dimensional fluorescence and circular dichroism spectral results.

