title: Fusion proteins containing neuropeptides as novel insect contol agents: snowdrop lectin delivers fused allatostatin to insect haemolymph following oral ingestion.
abstract: The mannose-binding lectin from snowdrop (Galanthus nivalis agglutinin: GNA), when fed to insects, binds to the gut epithelium and passes into the haemolymph. The potential for GNA to act as a carrier protein to deliver an insect neuropeptide, Manduca sexta allatostatin (Manse-AS), to the haemolymph of lepidopteran larvae has been examined by expressing a GNA/Manse-AS fusion protein (FP) in Escherichia coli, and feeding purified FP to larvae of the tomato moth Lacanobia oleracea. FP, administered at 1.5 or 0.5% of dietary proteins, was found to strongly inhibit feeding and prevent growth of fifth stadium larvae, whereas neither GNA nor Manse-AS alone, nor a mixture of GNA and Manse-AS in control treatments, had deleterious effects at similar levels. Elevated levels of material reacting with anti-Manse-AS antibodies were detected in the haemolymph of insects fed diets containing FP, suggesting that transport of the peptide had occurred. Evidence for the delivery of intact FP to the haemolymph was provided by the co-elution of Manse-AS-like immunoreactivity with standard FP after size exclusion chromatography of haemolymph from FP-fed larvae. GNA/Manse-AS and similar fusion proteins offer a novel and effective strategy for delivering insect neuropeptides by oral administration, which could be used in conjunction with expression in transgenic plants to give crop protection in the field.
authors.affiliation: Central Science Laboratory, Department for Environment, Food and Rural Affairs, Sand Hutton, York YO41 1LZ, UK. e.fitches@csl.gov.uk
authors.forename: Elaine
authors.initials: E
authors.lastname: Fitches
authors.forename: Neil
authors.initials: N
authors.lastname: Audsley
authors.forename: John A
authors.initials: JA
authors.lastname: Gatehouse
authors.forename: John P
authors.initials: JP
authors.lastname: Edwards
mesh_terms: D000284:Administration, Oral; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D017931:DNA Primers; D004068:Digestive System Physiological Phenomena; D006386:Hemagglutination Tests; D006458:Hemolymph / Q000502:physiology*; D007313:Insecta / Q000502:physiology*; D037241:Mannose-Binding Lectins / Q000008:administration & dosage / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D037121:Plant Lectins / Q000008:administration & dosage / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D037241:Mannose-Binding Lectins; D009479:Neuropeptides; D037121:Plant Lectins; D011993:Recombinant Fusion Proteins; C063117:snowdrop lectin