extraction of lipase from the intestine of rainbow trout (oncorhynchus mykiss) and effects of inhibitors and metals on its activity

aquatic animals are important resources for extraction of valuable compounds such as enzymes. in this study, lipase was extracted from the intestine of rainbow trout. samples were defatted with acetone several times; ammonium sulphate (60%) was used for precipitation followed by ultrafiltration for concentrating the samples. the final purification of the enzyme was performed by passing of the samples through g-75 column chromatography. after extraction, effects of two inhibitors were investigated on the activity of the enzyme. the enzyme activity was assayed by p-nitrophenyl palmitate as a substrate. the results showed that ethylenediaminetetraacetic acid and phenylmethylsulfonyl fluoride had significant inhibitory effects on the lipase activity (p<0.05). mncl2, cacl2 and mgcl2 significantly increased the lipase activity (p<0.05), while kcl and nacl decreased the activity (p<0.05). so when intestinal lipase of rainbow trout is used as an additive in related industries, these inhibitors can be used for inhibiting enzyme activity.