Phospholipase A Activity in Rainbow Trout Muscle

Abstract

A sensitive method for assay of phospholipase A activity in the lateral line muscle of rainbow trout is described. ¹⁴C labelled lecithin was converted to lysolecithin by the enzyme. Unreacted lecithin was removed by silicic acid column chromatography and the lysolecithin recovered by thin-layer chromatography. The amount of lysolecithin formed was between 43 and 87 mμmoles per gram lateral line muscle per hour under the experimental conditions. The amount formed was directly proportional to time between half an hour and 4 hr and the optimum pH was found to be approximately 7.5. The results are discussed in relation to the enzymic activity previously demonstrated in fish muscle.