Changes in activity of proteases during embryogenesis of Anagasta kuehniella (insecta)

Abstract

1. 1. Cleavage of hemoglobin by homogenates of eggs of Anagasta kuehniella (Zeller) has been investigated. Three distinct pH optima (4·5, 6·9 and 9·5) of activity are manifested during embryological development. Several characteristics suggest the two activities with lower pH optima are of the cathepsin type while activity at the high pH may be of the trypsin type. 2. 2. The activity having optimum at pH 6·9 fluctuates in a diurnal manner during the 4-day development period. Such diurnal fluctuations in activity persisted even in eggs in which embryonic development had been arrested by exposure to 57°C for 15 min within 6 hr after oviposition. 3. 3. The protein complement undergoes virtually complete alteration during embryogenesis. Loss of soluble proteins from the egg near the end of the developmental period seems to correlate with increases in proteolytic activity.