title: Purification and characterization of a trypsin-like digestive enzyme from spruce budworm (Choristoneura fumiferana) responsible for the activation of delta-endotoxin from Bacillus thuringiensis.
abstract: A trypsin-like enzyme purified from spruce budworm (Choristoneura fumiferana) gut juice has a molecular mass of 25 kDa and its pH activity profile indicates a pKa of 8. Sequence homology with bovine trypsin of the N-terminus and active site, and the ionization dependence for catalysis, reflect the typical trypsin-like activities measured. The action of this enzyme (designated CFT-1) is compared to the neat gut juice with regard to the proteolytic activation of the delta-endotoxin from Bacillus thuringiensis.
authors.affiliation: Forest Pest Management Institute, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Milne
authors.forename: H
authors.initials: H
authors.lastname: Kaplan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism*; D001427:Bacterial Toxins; D004064:Digestive System / Q000201:enzymology; D004731:Endotoxins / Q000378:metabolism*; D004798:Enzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006460:Hemolysin Proteins; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000494:pharmacology; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D014357:Trypsin
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D004798:Enzymes; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D007531:Isoflurophate; D014357:Trypsin