Induction of cecropin-like and attacin-like antibacterial but not antiviral activity in Heliothis virescens larvae.
Inducible cecropin-like and attacin-like proteins were isolated from immune hemolymph obtained from vaccinated Heliothis virescens larvae. The attacin-like protein had a molecular weight of approximately 25,000 daltons and was not dialyzable. The cecropin-like peptide had an estimated molecular weight of 6,000-7,000 daltons and was dialyzable, heat-stable and sensitive to trypsin digestion. The cecropin-like peptide showed bactericidal activity against Escherichia coli and Enterobacter cloacae, and the attacin-like protein showed bactericidal activity against E. coli. The immune hemolymph was bactericidal against E. coli, E. cloacae and Pseudomonas aeruginosa. Ultrastructural cell envelope damage to E. coli, produced by the immune hemolymph, was observed by scanning electron microscopy. No antiviral activity by the inducible cecropin-like and attacin-like proteins was detected against herpes simplex virus-1 and the vesicular stomatitis virus.
Ourth
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DD
Department of Biology, University of Memphis, TN 38152.
Lockey
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TD
Renis
H E
HE
D000818:Animals; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000633:toxicity; D000998:Antiviral Agents; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D016972:Enterobacter cloacae / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects / Q000648:ultrastructure; D006458:Hemolymph / Q000502:physiology; D007301:Insect Hormones / Q000096:biosynthesis* / Q000302:isolation & purification / Q000633:toxicity; D019476:Insect Proteins; D007814:Larva; D007915:Lepidoptera / Q000378:metabolism / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011550:Pseudomonas aeruginosa / Q000187:drug effects
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000998:Antiviral Agents; D007301:Insect Hormones; D019476:Insect Proteins; C039711:attacin antibacterial protein, insect