title: Radiochromatographic assay of metabolites of the oostatic peptide labeled in different positions of the peptide chain.
abstract: Reversed-phase high-performance liquid radio-chromatography (radio-HPLC) was set up to detect the time course of labeled degradation product formation of the pentapeptide H-Tyr-Asp-Pro-Ala-Pro-OH (5P), which has oostatic effects in different insect species. The detection limit of the system was in the range of 80-150 Bq. To follow formation of the degradation products, three amino acid residues in 5P were independently tritiated: Tyr1, Pro3 and Pro5. Each of the three tritiated peptides was analyzed after incubation with fresh hemolymph or ovaries of Neobellieria bullata. In the incubation mixture, free terminal amino acids and shortened sequences of 5P were identified. A metabolite of tyrosine represented the only exception; it was finally identified as water using degradation of [3H]Tyr by tyrosinase. Metabolic degradation of [3H]Tyr-5P was found to be considerably quicker than that of H-[3H]Tyr-Asp-Pro-Ala-OH (4P). The degradation of 5P was considerably slower in ovaries in comparison to hemolymph.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo sq. 2, 166 10 Prague 6, Czech Republic.
authors.forename: Richard
authors.initials: R
authors.lastname: Tykva
authors.forename: Jan
authors.initials: J
authors.lastname: Hlavácek
authors.forename: Vera
authors.initials: V
authors.lastname: Vlasáková
authors.forename: Bohuslav
authors.initials: B
authors.lastname: Cerný
authors.forename: Lenka
authors.initials: L
authors.lastname: Borovicková
authors.forename: Blanka
authors.initials: B
authors.lastname: Bennettová
authors.forename: Josef
authors.initials: J
authors.lastname: Holík
authors.forename: Jirina
authors.initials: J
authors.lastname: Slaninová
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004175:Diptera / Q000378:metabolism; D005260:Female; D006458:Hemolymph / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism* / Q000493:pharmacokinetics / Q000592:standards; D010053:Ovary / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D014316:Tritium; D014443:Tyrosine / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D014316:Tritium; C065612:Peptide oostatic hormone; D014443:Tyrosine