Mass spectrometry and characterization of Aedes aegypti trypsin modulating oostatic factor (TMOF) and its analogs.
Autor(es): Borovsky, D.; Carlson, D. A.; Griffin, P. F.; Shabanowitz, J.; Hunt, D. F.
Resumo: Trypsin modulating oostatic factor (TMOF), a decapeptide that directly inhibits the biosynthesis of trypsin- and chymotrypsin-like enzymes in epithelial cells of mosquito midgut and indirectly inhibits vitellogenesis in anautogenous females, has been sequenced by Fourier transform mass spectrometry analysis. The peptide has a primary amino acid sequence of NH sub(2)-Tyr-Asp-Pro-Ala-(Pro) sub(6)-COOH and probably exhibits left-handed helical conformation as was shown by computer stereoview simulation. The factor is metabolized very rapidly (half-life of 1.6 h) in intact mosquitoes when injected after the blood meal. Inhibition of trypsin biosynthesis was followed in ligated abdomens, which synthesize trypsin but do not metabolize TMOF. At concentrations of 3 x 10 super(-9) M and 6.8 x 10 super(-6) M, TMOF inhibited 50 and 90% of trypsin-like enzyme biosynthesis, respectively. Several analogs of varying chain lengths were synthesized and evaluated for biological activity using dose-response curves.
Palavras-Chave: Enzyme inhibitors; Inhibitors; Amino acid sequence; Vitellogenesis; Enzymes; Biosynthesis; Hormones; Biological activity; Peptide hormones; Aedes aegypti; Culicidae; Diptera
Imprenta: Insect Biochemistry and Molecular Biology, v. 23, n. 6, p. 703-712, 1993.
Descritores: Aedes aegypti - Biosynthesis ; Aedes aegypti - Cell
Data de publicação: 1993
