Interaction between secondary lipid oxidation products and hemoglobin with multi-spectroscopic techniques and docking studies

This study aimed to explore the effect of secondary lipid oxidation products (SLOPs) on hemoglobin (Hb) in chicken model. The fluorescence quenching technique and molecular docking were employed, and the apparent binding constants Ksv and the binding site numbers of SLOPs with Hb were calculated. The results revealed that three SLOPs (hexanal, benzaldehyde, and 2-pentanone) obviously promoted the oxidation of Hb, which is consistent with the change of Hb hydrophobicity, particle size, polydispersity index and zeta potential. The SLOPs strongly quenched the intrinsic fluorescence of Hb and triggered the alterations in the Hb structure. Hydrophobic interaction was the main force between SLOPs and Hb. Among the three SLOPs, hexanal demonstrated more stronger oxidation on Hb, which is closely related to its hydrophobic ability and structure characteristic, especially 10 μM hexanal is more prone to form an obvious unfolded structure and caused molecular aggregation than lower concentrations.