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Toxic interaction between acid yellow 23 and trypsin: spectroscopic methods coupled with molecular docking
Jing Wang1, Rutao Liu, Pengfei Qin
1Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan 250100, People's Republic of China.
Acid yellow 23 (AY23), an azo dye, was found to inhibit trypsin activity by binding to its structure. This interaction, driven by electrostatic forces, may contribute to the dye's toxic effects on organisms.
Area of Science:
- Biochemistry
- Toxicology
- Dye Chemistry
Background:
- Acid yellow 23 (AY23) is a widely used azo dye with potential environmental and health risks.
- Trypsin is a crucial digestive enzyme whose function can be affected by external compounds.
Purpose of the Study:
- To investigate the toxic effects of Acid yellow 23 on trypsin.
- To elucidate the interaction mechanism between AY23 and trypsin at a molecular level.
Main Methods:
- Spectroscopic techniques (fluorescence quenching) were employed to study the binding.
- Thermodynamic parameters were calculated to understand the binding forces.
- Molecular docking simulations were performed to identify interaction sites and mechanisms.
Main Results:
- AY23 quenched trypsin's intrinsic fluorescence through static quenching, indicating complex formation.
- Binding constants and thermodynamic data suggested predominant electrostatic interactions with one binding site.
- Conformational changes in trypsin's structure and microenvironment were observed.
- Molecular docking revealed interactions with His 57 and Lys 224 residues, leading to enzyme inhibition.
Conclusions:
- AY23 interacts with trypsin, causing structural alterations and inhibiting enzyme activity.
- The binding is primarily driven by electrostatic forces.
- These interactions suggest a potential mechanism for AY23 toxicity within biological systems.
