title: Juvenile hormone esterase activity repressive factor in the plasma of parasitized insect larvae.
abstract: A proteinaceous factor that represses plasma juvenile hormone esterase activity in parasitized insect larvae has been isolated and partially characterized from last instar larvae of the armyworm Pseudaletia separata parasitized with the wasp Apantales kariyai. Purification procedures consisted of extraction with 25% ethanol, gel filtration and reversed phase high performance liquid chromatography. Plasma juvenile hormone esterase activity in Day 3 last instar larvae was repressed by 50% when larvae were injected on Days 1 and 2 with 6.5 pmol of the purified peptide, which has a molecular weight of about 4,500 Da. The application of the factor also causes more than a 2-day delay in the onset of pupation. The sequence of 23 amino acid residues at the amino terminus of the factor was determined as follows: H-Glu-Asn-Phe-Ser-Gly-Gly-Xaa-Val-Ala-Gly-Tyr-Met- Arg-Thr-Pro-Asp-Gly-Arg-Xaa-Lys-Pro-Thr-Phe-Tyr-Gln-.
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hayakawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors*; D002851:Chromatography, High Pressure Liquid; D016207:Cytokines; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D006927:Hymenoptera; D019476:Insect Proteins; D007814:Larva / Q000201:enzymology; D007915:Lepidoptera / Q000201:enzymology / Q000469:parasitology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011506:Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D014863:Wasps
chemical_list: D016207:Cytokines; D004791:Enzyme Inhibitors; D019476:Insect Proteins; D011506:Proteins; C068690:growth blocking peptide, Apanteles kariyai; D002265:Carboxylic Ester Hydrolases; C038003:juvenile hormone esterase