Isolation and structure determination of a paralytic peptide from the hemolymph of the silkworm, Bombyx mori.
A peptide with paralytic activity in larvae of the silkworm, Bombyx mori, was isolated from its hemolymph. Purification procedures consisted of extraction with 50% acetone, Vydac C4 reversed-phase cartridge elution and 4 steps of reversed-phase HPLC. Injection of the purified peptide into 4th instar B. mori larvae caused rapid and rigid paralysis for 2 min at a dose of 3.4 ng/larva. This paralytic peptide consists of 23 amino acid residues containing 2 cysteines with an intra-disulfide bond. The complete amino acid sequence is: H-Glu-AsnPhe-Val-Gly-Gly-Cys-Ala-Thr-Gly-Phe-Lys-Arg-Thr-Ala-Asp-G ly-Arg-Cys-Lys-Pro-Thr-Phe-OH. The relationship between structure and the biologic activity of synthetic analogs indicated that the entire amino acid sequence and the intra-disulfide bond were necessary for biological activity.
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Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Japan.
Nagata
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Suzuki
A
A
Kataoka
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D012831:Bombyx / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006458:Hemolymph / Q000737:chemistry*; D007814:Larva / Q000737:chemistry; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology*; D010243:Paralysis / Q000139:chemically induced*; D017421:Sequence Analysis; D013329:Structure-Activity Relationship
D004220:Disulfides; D009479:Neuropeptides; C121924:paralytic peptide, insect