Abstract: | The phospholipase A2 and lysophospholipase A1 activities were determined in various mixtures. When estimating the phospholipase A2 activity in venoms of snakes and insects the known methods based on measuring a change in the optical density of the egg yolk suspension are not acceptible if in investigated object besides phospholipases lysophospholipases are present (venoms of viper and giant hornet). In this case anomalous curves of changes in the system optical density in time are obtained. At the same time the analysis of such curves revealed that the method can be rather sensitive for determining lysophospholipases in venoms, as well as in phospholipase preparations of different purification, including electrophoretically homogeneous preparations. The results obtained enabled us to estimate the content of phospholipase A2 and lysophospholipase A1 in the venom of giant hornet and in its fractions, obtained during isolation and purification of the concerned enzymes. |