ABSTRACT
Activity of acidic proteinase in the midgut of larval Parasarcophaga surcoufi was investigated and partially characterized. Larval midgut extract showed a moderate acidic pH [pH 4] optimum for hydrolysis of hemoglobin. The proteolytic activity of the larval midgut was estimated by hydrolysis of hemoglobin and was found to be inhibited by pepstatin [aspartic proteinase inhibitor], dithiothreitol [DTT] and mercaptoethanol, while it was not inhibited by soybean trypsin inhibitor [STI] and EDTA. These characteristics may imply that cathepsin D-like proteinase is an effective acidic proteinase present in the Parasarcophaga surcoufi larval midgut
Subject(s)
Insecta , /enzymology , Larva , Peptide Hydrolases/biosynthesis , MiceABSTRACT
The contribution of both pentose phosphate cycle [PPC] and glycolytic-citric acid cycle [GCAC] to metabolism of glucose by different physiological states of Dermacentor andersoni female was evaluated. The radiorespirometric method was used after injection of glucose 3,4-[14]C [G[3,4]] glucose-1-[14]C [G[1]] and glucose-6-[14]C [G[6]] into the hemocoel of separate females of different physiological states and following by the expired [14]CO[2], was trapped for 7 hrs. at 1 hr. intervals. The contribution of PPC to glucose metabolism is 23, 50 and 84% in the unfed, unmated-partly fed, and ovipositing females respectively. Accordingly, the GCAC contribution is 77, 50 and 16% in the same physiological states respectively. The greatly increasing trend in PPC activity from the unfed to the ovipositing state is attributed to increasing need to requisite two-carbon unit intermediates for other metabolic processes. The metabolic products of PPC used in biosynthetic processes associated with feeding and oogenesis is a reliable reason for the active operation of this metabolic pathway
Subject(s)
Radiometry , Pentosephosphates , GlucoseABSTRACT
The fed female argasid tick Argas [Persicargas] arboreusmolts when topically applied with 1 micro g ecdysterone, inokosterone or cyasterone per tick. This is not observed in case of the female ixodid tick Rhipicephalus sanguineus even at 100 micro g amount per tick. This is suggested to be due to a difference in specific genetical instruction in their epidermal cells and also to a complementary state of their neurosecretions