Exploring How Berberine Fatty Acid Salts Interact with Lysozyme

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A new study published in the journal Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy provided new information on how berberine mid-chain fatty acid salts interact with lysozyme (1). The results presented in this study give new insights into protein–ligand binding and potential biomedical applications. The research team employed a combination of advanced spectroscopic methods and molecular docking techniques in their study.

In the study, the research team focused on three berberine salts, including berberine caproate ([BBR][C6]), berberine heptylate ([BBR][C7]), and berberine octoate ([BBR][C8]), and their interactions with lysozyme (Lyz), a well-studied enzyme with antibacterial activity (1). Berberine is a compound that is extracted from a group of shrubs called berberis, and it has been used extensively in traditional Chinese medicine (2).

In their study, the researchers explored whether berberine salts form stable, non-fluorescent complexes with the enzyme. To test this, they used steady-state fluorescence and UV–visible (UV-vis) absorption spectroscopy. These techniques unveiled that the binding mechanism between [BBR][Cn] compounds and Lyz followed a static quenching process with a 1:1 binding ratio (1).

Overall, the researchers used spectroscopic analyses, including UV–vis, synchronous fluorescence, three-dimensional fluorescence, and Fourier transform infrared (FT-IR), to uncover significant conformational changes in the lysozyme upon binding (1). Notably, the α-helix content of Lyz decreased while β-sheet content increased, indicating that the berberine salts alter the enzyme’s secondary structure (1). Förster resonance energy transfer (FRET) studies further quantified the molecular distance between Lyz and the berberine compounds, supporting the observed conformational shifts (1).

The main drivers of the binding process include hydrophobic interactions, van der Waals forces, and hydrogen bonding. The researchers determined this through thermodynamic analyses and molecular docking simulations (1). The binding event was shown to enhance the esterase-like activity of lysozyme, pointing toward functional as well as structural consequences. The researchers also found that the strength of the interaction depended on environmental factors such as pH and temperature, as well as the length of the anionic alkyl chain in the berberine salts (1).

According to the scientists, the findings help us gain a better understanding of how natural compounds like berberine derivatives interact with key enzymes at the molecular level (1). Ultimately, the main goal is that this knowledge could inform the development of new drug delivery systems and therapeutic applications where modulation of enzyme activity is desirable.

References

1. Cheng, Y.; Yan, Z.; Hu, L. Unveiling the Binding Details of Berberine Mid-chain Fatty Acid Salts on Lysozyme: Multi-spectroscopy and Molecular Docking. Spectrochimica Acta A: Mol. Biomol. Spectrosc. 2026, 347, 126902. DOI: 10.1016/j.saa.2025.126902
2. Gunnars, K. Berberine – A Powerful Supplement With Many Benefits. Healthline.com. Available at: https://www.healthline.com/nutrition/berberine-powerful-supplement (accessed 2025-09-15).