Binding effects of quercetin on the structural and functional properties of major royal jelly protein 1 under...

This study aims to investigate the effects of pH levels on the binding ability and antioxidant activity of major royal jelly protein 1 (MRJP1) with quercetin (Q) and to elucidate the interaction mechanisms using multi-spectroscopy and molecular docking analysis. The results showed that the quenching of MRJP1 by Q was governed by a static quenching mechanism at pH 5.5, 7.0, and 8.5. MRJP1 exhibited a higher binding affinity for Q at pH 8.5 and 7.0 than at pH 5.5. Hydrophilic interaction was the main driving force for the formation of the MRJP1-Q complex at pH 5.5-8.5. Molecular modeling further revealed that Q preferred to interact with the central domain of MRJP1 across all tested pH conditions. Importantly, the formation of the MRJP1-Q complex increased the apparent solubility of Q and synergistically enhanced the ABTS⁺ radical scavenging capacities of both components. These findings suggest that the MRJP1-Q complex represents a nutritionally valuable substance with potent antioxidant capabilities, holding promise for functional food and nutraceutical applications.