Analogs of the H-Tyr-Asp-Pro-Ala-Pro-OH pentapeptide with D-amino acid residues either in differing or in all of the positions of the sequences were prepared and their oostatic potency was compared with that of the parent pentapeptide. The D-amino acid residue containing analogs exhibited an equal or even higher oostatic effect in the flesh fly Neobellieria bullata than the parent peptide. Contrary to the rapid incorporation of radioactivity from the labeled H-Tyr-Asp-[3H]Pro-Ala-Pro-OH pentapeptide into the ovaries of N. bullata in vitro, the radioactivity incorporation from the labeled pentapeptides with either D-aspartic acid or D-alanine was significantly delayed. As compared to the parent pentapeptide, also the degradation of both the D-amino acid-containing analogs mentioned above proceeded at a significantly lower rate. The decreased intake of radioactivity, the lower degradation and finally also the high oostatic effect may be ascribed to the decreased enzymatic degradation of the peptide bonds neighboring the D-amino acid residues in the corresponding peptides. The introduction of the non-coded D: -amino acids thus enhances the oostatic effect in N. bullata owing to the prolonged half-life of the corresponding pentapeptides, which can thus affect more ovarian cells.
- MeSH
- alanin chemie metabolismus MeSH
- aminokyseliny biosyntéza chemie MeSH
- kyselina D-aspartová chemie metabolismus MeSH
- magnetická rezonanční spektroskopie MeSH
- ovarium cytologie růst a vývoj MeSH
- peptidy chemie MeSH
- proteolýza MeSH
- Sarcophagidae chemie růst a vývoj MeSH
- tritium chemie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
?-5-Aza-2'-deoxy cytidine was labeled by tritium on the C-6 of the heterocyclic triazine ring. The structure of the ?-5-aza-2'-deoxy-[6-3H]cytidine and the position of the label was proved by 3H and 1H NMR. The specific activity was 0.71 TBq mmol-1 (19.2 Ci mmol-1) and radiochemical purity was >99%. The long term stability of the product during the storage at -21 and -72 °C was followed by radio-HPLC.
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.
- MeSH
- Diptera metabolismus MeSH
- financování organizované MeSH
- hemolymfa metabolismus MeSH
- oligopeptidy farmakokinetika metabolismus normy MeSH
- ovarium metabolismus MeSH
- referenční standardy MeSH
- reprodukovatelnost výsledků MeSH
- sekvence aminokyselin MeSH
- tritium MeSH
- tyrosin metabolismus MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
