HYPERTREHALOSEMIC INSECT PEPTIDE PERIPLANETIN CC-2 AND ITS ANALOGS - SYNTHESIS AND BIOLOGICAL EVALUATION

The effects of hypertrehalosaemic octapeptides (peptides from AKH fami ly) on transcription and trehalosegenesis in the fat body of adult fem ales of Tenebrio molitor L. were examined. A synthetic hypertrehalosae mic peptide from CC of Periplaneta americana periplanetin CC-2 (Pea-CA H-II) Glp-Leu-Thr-Phe-Thr-Pro-Asn-Trp-amide (1), its new synthetic ana logues Glp-Leu-Thr-Phe-Thr-Pro-Asn-Phe-amide (2), Glp-Leu-Thr-Phe-Thr- Pro-Asn-D-Trp-amide (3), Glp-Leu-Thr-Phe-Thr-Pro-Asn-D-Phe-amide (4), and an octapeptide from T. molitor Glp-Leu-Asn-Phe-Ser-Pro-Asn-Trp-ami de (Tem-HrTH) (5) were tested. Peptides 2, 3 and 5 suppress transcript ion in the fat body tissue measured as incorporation of [H-3]-uridine into total RNA. The rate of RNA inhibition in the tissue depends on th e peptide concentration. Periplanetin CC-2 (2) was inactive in this te st. Endogenic T. molitor octapeptide (5) stimulates trehalose release from the fat body of females, whereas Pea-CAH-II analogues (2-4) do no t increase trehalose release from this tissue.