FIG. 3.

Analytical IEF analysis of proteinases produced during penetration of M. sexta cuticle. Following 48 h of incubation, enzymes were extracted with 0.2 M potassium phosphate buffer. Shown are extracts from uninoculated cuticle (lane a), inoculated cuticle presoaked in water (lane b), inoculated cuticle presoaked in 0.1 M HEPES buffer (pH 8) (lane c), and inoculated cuticle presoaked in 50 mM citric acid-sodium phosphate buffer (pH 3) (lane d), extract from lane d treated with pepstatin for 10 min (lane e), extract from lane b incubated with 1 mM phenanthroline for 10 min (lane f), and extract from lane b incubated with PMSF for 10 min (lane g).