Kinetic and thermodynamic insights into the interaction of Aβ1-42 with astaxanthin and aggregation behavior of Aβ1-42: Surface plasmon resonance, microscopic, and molecular docking studies

Amyloid-beta 1-42 (A beta 1-42) aggregation is considered as an important process in the pathology of Alzheimer's disease (AD). Astaxanthin (ATX), a xanthophyll carotenoid, has a broad range of biological activities such as neuroprotective one. The present study aimed to elucidate the interaction of ATX with A beta 1-42, as well as its effect on A beta 1-42 aggregates under different conditions. Based on the surface plasmon resonance (SPR) results, ATX possessed a high affinity towards A beta 1-42 and the binding process was spontaneous, endothermic, and entropy-driven. Additionally, the binding affinity of ATX to A beta 1-42 was glucose and insulin concentration-dependent. Hydrophobic interactions may play an important role in the interaction between ATX and A beta 1-42. The results of SPR, thioflavin T (ThT), and transmission electron microscopy (TEM) analyses represented the dependency of the anti-amyloid activity of ATX on glucose, insulin, and ATX concentrations. Further, molecular docking results indicated the presence of some same binding sites on A beta 1-42 for ATX and glucose, as well as ATX and insulin, which suggests the possible competition between the molecules for A beta 1-42 binding. Furthermore, the MTT results confirmed that ATX effect on the viability of A beta 1-42-treated PC12 cells was dependent on glucose, insulin, and ATX concentrations. In general, the results provided further insights into the interaction between A beta 1-42 and ATX, as well as the effect of ATX on A beta 1-42 aggregates under various conditions.

Automated summary

The study explored the interaction between ATX and Aβ1-42, finding high affinity between them dependent on glucose and insulin concentrations. ATX's anti-amyloid activity on Aβ1-42 was influenced by glucose, insulin, and ATX concentrations.