Interactions of Curcumin with Porcine Lipoxygenase and Its Effect on Protein Structure

The interaction between curcumin and porcine 12-Lipoxygenase(LOX)was investigated by spectrophotometry,fluorescence spectroscopy and circular dichroism(CD). The results showed that curcumin inhibited the activity of porcine 12-LOX.The more concentration it was,the more inhibition effect it behaved. The IC₅₀ value of curcumin inhibited 12-LOX was 2.156 μg/mL. Fluorescence results showed that curcumin had strong quenching effects on porcine 12-LOX,and the quenching mechanism was static quenching. The interaction between curcumin and porcine 12-LOX was mainly van der Waals force and hydrogen bonding. Synchronous fluorescence spectroscopy indicated that the binding site of curcumin to porcine 12-LOX was closer to the tryptophan residue. CD chromatography showed that curcumin interacted with porcine 12-LOX and made the LOX secondary structure changed.