Insights into the binding mode of curcumin to MD-2: studies from molecular docking, molecular dynamics simulations and experimental assessments.

Curcumin, a natural product, has been shown to possess notable anti-inflammatory activities and numerous studies have been carried out on its clinical applications. Recently, several reports mentioned that myeloid differentiation protein 2 (MD-2) may be the direct target of curcumin in the inhibition of lipopolysaccharide (LPS) signaling. However, the exact interaction between curcumin and MD-2 is still incompletely understood. In the present study, computational and experimental methods were employed to explore the underlying structural mechanism of curcumin binding to the MD-2 protein. Molecular docking and molecular dynamics (MD) simulation studies showed that curcumin could be embedded into the hydrophobic pocket of MD-2 and form stable hydrogen bonding interactions with residues R90 and Y102 of MD-2. Moreover, experimental results of curcumin binding to the MD-2(R90A/Y102A) mutant further confirmed that residues ARG-90 and TYR-102 contribute to the recognition process of curcumin binding to the MD-2 protein. In conclusion, we have explored the binding mechanism of curcumin to MD-2; more importantly, this work could offer useful references for designing novel analogs of curcumin as potential anti-inflammatory agents targeting the MD-2 protein.