The Effect of Phenol on the Activity and Temperature Characteristicsof Peptidases in Chironomid Larvae at Different рН Values
The effect of phenol (Ph, 0.25 mmol/L) on the activity and temperature dependence of casein- and hemoglobinlytic peptidases functioning in the whole organism of chironomid larvae <i>Chironomus</i> sp. within the temperature range of 0−70ºС at different рН values (3.0, 5.0 and 7.4) was investigated. The temperature optimum of the studied peptidases of chironomid larvae corresponds to 40°С. Under the influence of phenol, the activity of caseinlytic peptidases increases, more significantly at 20°С and рН 5.0 (3.3 times), that of hemoglobinlytic peptidases – at рН 3.0 (3.5 times). The effect successively decreases from рН 3.0 up to рН 7.4. under both temperatures. In the presence of phenol, the shape of the curves of the temperature dependence and the Q<sub>10</sub> values transform most significantly in the zone of high temperatures. The values of activation energy (<i>E</i><sub>act</sub>) of the process of hydrolysis of casein and hemoglobinlytic peptidases in the zone of low and high temperatures are different. In the presence of phenol, <i>E</i><sub>act</sub> values of the process of hydrolysis of casein caseinlytic peptidases at рН 7.4 are increased, at рН 5.0 they decreased in the zone of high temperatures. <i>E</i><sub>act</sub> values of the process of hydrolysis of hemoglobinlytic peptidases are decreased in most cases. The mechanisms of the influence of phenol on peptidase activity and digestive processes in fish-benthophagous eating of chironomid larvae are discussed.