Agaricus bisporus lectin – isoflavone molecular interactions focusing on the inclusion of glycosylation from genistein to genistin

Isoflavones like genistein (GNE) and genistin (GNI), its glycosylated counterpart, known for their health benefits, commonly occur in plant-based foods. This study investigates their molecular interactions with Agaricus bisporus lectin (ABL), a protein with nutraceutical potential. Interactions of ABL with GNE and GNI, were found to significantly increase β -sheet components of the protein by around 8.0 and 6.5 %, respectively, as determined by Fourier transform infrared (FTIR) and circular dichroism (CD) analyses. α -Helical structures were reduced by a corresponding amount, with in silico docking suggesting that these were the main structural changes in the presence of the isoflavones. The ligands were found to interact with the glucose binding domain (GBD) of the protein, with GNE displaying stronger interaction strength, as shown by fluorescence quenching analysis, estimated to be 3.68 × 10 5 L mol −1 , compared to 1.66 × 10 5 L mol −1 for GNI. Hence, despite interacting with the GBD of the protein, glycosylation did not improve the binding strength for GNI with ABL, underlining the ability of the aglycone isoflavone to interact strongly with this domain leading to the formation of π-alkyl hydrophobic forces between ligand and host. These findings provide insights on the potential use of ABL in functional food formulations or nutraceuticals. • Agaricus bisporus lectin interactions with genistein and genistin were studied. • Both ligands were found to interact with the glucose binding domain of the protein. • Secondary structural changes occurred in the protein due to this interaction. • Aglycone isoflavone binds strongly with lectin due to π-alkyl hydrophobic interactions.