title: Processing of delta-endotoxin from Bacillus thuringiensis subsp. kurstaki HD-1 and HD-73 by gut juices of various insect larvae.
abstract: Midgut juices were prepared from Adoxophyes sp., smaller tea tortrix (STT); Bombyx mori, silkworm (SW); Spodoptera litura, common cutworm (CCW); Plutella xylostella, diamondback moth (DBM); and Musca domestica, housefly (HF) and immobilized onto Sepharose 4B. delta-Endotoxins (ICPs) from Bacillus thuringiensis subsp. kurstaki HD-1 and HD-73 were digested by these immobilized gut juice proteases. All gut juices tested derived relatively proteolytic resistant cores from ICP. The molecular sizes of these cores, about 55 kDa in SDS-PAGE, were resulted. In the case of CCW, however, digestion was very strong and only 1/20 concentration of core protein remained relative to other digests. The N-terminal amino acid sequencing of the core proteins showed that they were truncated at the very end of the N-terminus of protoxin, CryIA, at different sites. Although housefly larvae were completely insensitive to active toxin, the gut juice produced the core, suggesting that the housefly may lack the binding sites for the core-active toxin.
authors.affiliation: Laboratory of Biochemistry and Genetic Engineering, Tsukuba Laboratories of Research and Development, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ogiwara
authors.forename: L S
authors.initials: LS
authors.lastname: Indrasith
authors.forename: S
authors.initials: S
authors.lastname: Asano
authors.forename: H
authors.initials: H
authors.lastname: Hori
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004063:Digestion / Q000502:physiology; D004731:Endotoxins / Q000378:metabolism*; D006460:Hemolysin Proteins; D007313:Insecta / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D007814:Larva / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis