| The Heteropoda venatoria is one of the largest indoor spiders that are widely distributed in the world’s tropical and subtropical regions. Its venom can poison most of the insects to death. In this study we constructed the cDNA library of Heterpopda cenatoria poison gland and the partial transcriptome information were obtained. After analysis and screening of the library we identified the putative cysteine rich coding cDNA clone in the library that was most likely be toxic peptides of the spider. The polypeptide toxins of ICK motif contained six cysteines were picked out and be analyzed. These toxins could be divided into eight family named as A, B, C, D, E, F, G and H respectively. The full length precursor peptide of this familiar each shared by a characteristics that it contained signal peptide, intermediate peptide and mature peptide in sequence from N terminal to C terminal. And they were obvious characteristics in the signal peptide segments, intermediate peptide cleavage and amino acids between cysteine residues of mature peptide in each family.The crude venom of the spider was collected by electroporation stimulation and seperated by reversed-phase high performance liquid chromatography. In collected components in39peaks that detected by MALDI-TOF mass spectrometry some71molecules between1000-7000Da were obtained. The6virtual purified components of the crude venom are tested with mass spectrometry. The molecular weight of the6components are4581Da (18.4min),4639Da (26.1min),3272Da (37.2min),3926Da (40.8min),3919Da (44.9min) and3599Da (48.3min) each. The component of molecular weigh of3732Da was identified as the toxin KJ1(κ appa-SPRTX-Hvle) by peptide sequencing homology analysis and message composition. The KJ1was composed of29amino acid residues in which the6Cys form three disulfide bonds covalent by CⅠ-CⅣ, CⅡ-CⅤ,CⅢ-CⅥ, The amino acid sequences is deduced as DDCGTLFSGCDTSKDCCEGYVCHLWCKYK by mass spectrum test. Its encoding cDNA sequences was identified in the library. |
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