The amino-acid sequence of a peptide (PS-1) from Drosophila funebris: a paragonial peptide from males which reduces the receptivity of the female.

The substance, PS-1, produced in the paragonial gland of adult male Drosophila funebris influences the mating behavior of virgin female flies after injection. The substance was isolated and characterized as a 27-residue peptide. The complete amino acid sequence was determined by manual sequence analysis of tryptic peptides, automated Edman degradation, and carboxypeptidase A digestion. The sequence is Asp-Val/Leu-Pro-Ser-Ala-Asn-Ala-Asn-Ala-Asn-Gln-Arg-Thr-Ala-Ala-Ala-Lys-Pro-Gln-Ala-Asn-Ala-Glu-Ala-Ser-Ser. The ratio of Val : Leu in the second position of the sequence is 7:3. This is the first detailed report on an insect peptide which causes a biological response in the opposite sex following mating.