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Author Spotlight: A Computational Approach to Decipher Amino Acid Preferences in Multispecific Protein-Protein Interactions
Published on: January 26, 2024
A comprehensive insight into the effects of caffeic acid (CA) on pepsin: Multi-spectroscopy and MD simulations
Fatemeh Hashemi-Shahraki1, Behzad Shareghi1, Sadegh Farhadian1
1Department of Biology, Faculty of Science, Shahrekord University, P.O. Box.115, Shahrekord, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran.
Abstract:
The interaction between caffeic acid (CA) and pepsin was investigated using multi-spectroscopy approaches and molecular dynamic simulations (MDS). The effects of CA on the structure, stability, and activity of pepsin were studied. Fluorescence emission spectra and UV-vis absorption peaks all represented the static quenching mechanism of pepsin by CA. Moreover, the fluorescence spectra displayed that the interaction of CA exposed the tryptophan chromophores of pepsin to a more hydrophilic micro-environment. Consistent with the simulation results, thermodynamic parameters revealed that CA was bound to pepsin with a high binding affinity. The Van der Waals force and Hydrogen bond interaction were the dominant driving forces during the binding process. The circular dichroism (CD) spectroscopy analysis showed that the CA binding to pepsin decreased the contents of α-Helix and Random Coil but increased the content of β-sheet in the pepsin structure. Accordingly, MD simulations confirmed all the experimental results. As a result, CA is considered an inhibitor with adverse effects on pepsin activity.
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