Identification and molecular cloning of insecticidal toxins from the venom of the brown spider Loxosceles intermedia.
The venom of Loxosceles intermedia was investigated for the presence of insecticidal toxins active against Spodoptera frugiperda (Lepdoptera: Noctuidade), an insect that has caused great reductions in corn production in Brazil. A combination of gel filtration (Sephadex G-100) and ion-exchange chromatography (Carboxymethyl Cellulose, CM 52) resulted in four major fractions that were submitted to biological assay. Fraction 4 was further purified by a reverse phase HPLC (C18 Column) resulting in peptides active against Spodoptera frugiperda. Three new potential insecticidal toxins named LiTx x 1, LiTx x 2 and LiTx x 3 were identified. The partial amino terminal sequences of these peptides were obtained and used to clone the corresponding cDNAs with the help of degenerate oligonucleotides. The amino acid sequence deduced from the cDNA of LiTx x 1, LiTx x 2 and LiTx x 3 revealed mature proteins of approximately 7.4, 7.9 and 5.6 kDa.
Departamento de Farmacologia, ICB, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte Cep: 31270901, MG, Brazil.
Cibele Soares
CS
de Castro
Flávia Galindo
FG
Silvestre
Simone Costa
SC
Araújo
de Menezes Yazbeck
de MY
Gabriel
Oldemir C
OC
Mangili
Ivan
I
Cruz
Carlos
C
Chávez-Olórtegui
Evanguedes
E
Kalapothakis
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001938:Brazil; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D016000:Cluster Analysis; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects*; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D010455:Peptides / Q000633:toxicity*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013111:Spider Venoms / Q000235:genetics* / Q000633:toxicity*; D013112:Spiders
C043517:2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide; D018076:DNA, Complementary; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D010455:Peptides; D013111:Spider Venoms