Optimization of lipoxygenase extraction conditions in silver carp muscle and the study on its enzymatic properties

The extraction process and enzymatic properties of Lipoxygenase ( LOX) from silver carp muscle were evaluated.The extraction conditions of LOX were optimized by single-factor experiment and the storage stability, thermal stability, optimum p H of LOX were studied by circular dichroism and fluorescence spectroscopy.The effects of p H, ionic strength and the addition of EDTA, DTT on the enzyme activity and concentration of LOX were studied respectively.The results showed that the suitable extraction condition parameters were: p H7.8, ionic strength 50 mmol/L, EDTA 2 mmol/L and DTT 2 mmol/L, the enzyme concentration of LOX was ( 1.98 ± 0.037) mg/m L and the activity was ( 244.44 ± 5.93) U under that condition. Our present work showed that the enzyme activity of LOX was stable within 0² d under room temperature, the optimum p H was 7.8 and the optimum temperature was 40 ℃.