title: Purification and cDNA cloning of an insecticidal protein from the venom of the scorpion Orthochirus scrobiculosus.
abstract: Injection of crude venom from the scorpion Orthochirus scrobiculosus into larvae of Heliothis virescens (Lepidoptera: Noctuidae) caused trembling and uncoordinated movement before development of a progressive and prolonged flaccid paralysis. The isolation of the toxin (OsI-1) responsible for this effect of O. scrobiclosus venom is described. The molecular mass of OsI-1 toxin was 6994 Da, as determined by desorption mass spectroscopy. The complete primary structure of OsI-1 was deduced from the sequence of cDNA clones obtained by rapid amplification of cDNA ends (RACE) PCR. Comparison of the deduced amino acid sequence of OsI-1 with those of other insecticidal scorpion toxins indicates that it is a sodium (Na+) channel active depressant insect-selective toxin. The analysis of amino acid sequence of the toxin in conjunction with mass spectroscopy data indicates post-translational modification in maturation with the removal of 3 C-terminal amino acids and amidation of the C-terminus.
authors.affiliation: Laboratory of Neuroreceptors & Neuroregulators, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow.
authors.forename: S
authors.initials: S
authors.lastname: Kozlov
authors.forename: A
authors.initials: A
authors.lastname: Lipkin
authors.forename: E
authors.initials: E
authors.lastname: Nosyreva
authors.forename: A
authors.initials: A
authors.lastname: Blake
authors.forename: J D
authors.initials: JD
authors.lastname: Windass
authors.forename: E
authors.initials: E
authors.lastname: Grishin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002268:Carboxypeptidases / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D006868:Hydrolysis; D007202:Indicators and Reagents; D007306:Insecticides / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity; D007915:Lepidoptera; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry / Q000302:isolation & purification*; D014176:Protein Biosynthesis; D011506:Proteins / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012604:Scorpion Venoms / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D012605:Scorpions / Q000378:metabolism*; D017421:Sequence Analysis; D012997:Solvents; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin
chemical_list: D007202:Indicators and Reagents; D007306:Insecticides; D009498:Neurotoxins; C404752:OsI-1 toxin; D011506:Proteins; D012604:Scorpion Venoms; D012997:Solvents; D002268:Carboxypeptidases; D014357:Trypsin