title: Proteomic identification of a novel toxin protein (Txp40) from Xenorhabdus nematophila and its insecticidal activity against larvae of Plutella xylostella.
abstract: For the identification of a novel insecticidal protein, a two-dimensional liquid chromatography (PF-2D) system was used in a quantitative proteomic analysis of  Xenorhabdus nematophila  CBNU strain isolated from entomophagous nematode  Steinernema carpocapsae . Protein patterns obtained from minimum and maximum insecticidal activities during cultivation were contrasted, and a novel toxin protein (Txp40) was identified by MALDI-TOF/MS. The DNA sequence of the cloned toxin gene (1089 bp) has an open reading frame encoding 363 amino acids with a predicted molecular mass of 41162 Da. The txp40 identified in this study is most closely related to the known txp40 cloned from X. nematophila EB (ADQ92844) with 94.4% identical sequence residues. Following the expression of the newly identified toxin gene in  Escherichia coli , the insecticidal activity of the recombinant toxin protein was determined against  Plutella xylostella  larvae; a 56.7% mortality rate was observed within 24 h.
authors.affiliation: Department of Microbiology, Chungbuk National University, Cheongju, Chungbuk, South Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Park
authors.forename: Mina
authors.initials: M
authors.lastname: Kim
authors.forename: Jiho
authors.initials: J
authors.lastname: Min
authors.forename: Si-Myung
authors.initials: SM
authors.lastname: Lee
authors.forename: Kong-Sik
authors.initials: KS
authors.lastname: Shin
authors.forename: Sung-Dug
authors.initials: SD
authors.lastname: Oh
authors.forename: Suk-Jung
authors.initials: SJ
authors.lastname: Oh
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects* / Q000254:growth & development; D040901:Proteomics; D017168:Rhabditida / Q000382:microbiology*; D016415:Sequence Alignment; D020593:Xenorhabdus / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D007306:Insecticides