Open AccessSources of propionate for the biogenesis of ethyl-branched insect juvenile hormones: Role of isoleucine and valine
Author(s) -
Philip A. Brindle,
Fred C. Baker,
Leslie W. Tsai,
Carol C. Reuter,
David A. Schooley
Publication year - 1987
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.84.22.7906
Subject(s) - corpus allatum , juvenile hormone , valine , isoleucine , propionate , manduca sexta , methionine , biochemistry , chemistry , leucine , biology , hormone , amino acid , insect , botany
Corpora allata from adult femaleManduca sexta biosynthesize the sesquiterpenoid juvenile hormone (JH) III and the unusual ethyl-branched homologue JH IIin vitro . We maintained corpora allata in medium 199 using [methyl -3 H]methionine as the source of the JH methyl ester moiety and as a mass marker. This allowed measurement of the relative contributions of14 C-labeled precursors to the biogenesis of JH II and III carbon skeletons. We showed efficient incorporation of a propionate equivalent, from isoleucine or valine catabolism, into the ethyl-branched portion of JH II, using double-label liquid scintillation counting of isolated JHs and gas chromatography/mass spectrometry with selected ion monitoring of JH deuteromethoxyhydrin derivatives. Methionine was a poor source of propionate for JH II biosynthesis, while glucose, succinate, threonine, and β-alanine did not contribute propionate at all. Leucine, isoleucine, and glucose incorporated into JH III and the acetate-derived portion of JH II.