CDNA Cloning And Sequence Analysis Of Spider Peptide Toxins And The Toxinomics Study Of The Venom From The Spider Chilobrachys Jingzhao

In previous work, many components with different structures and functions were purified and characterized and the cDNA sequences of seven peptides were obtained from Ornithoctonus huwena Wang. In order to study the cDNA structures of spider peptides, which are significant for the understanding of the evolutionary relationship and the genetic classification of these peptides. In this study, six cDNAs encoding six toxins HWTX-III, HWTX-IIIa, HWTX-XI, JZTX-V, JZTX-XI and JZTX-XIV were cloned and sequenced. On the basis of their amino acid sequences, we designed and synthesized 3'RACE and 5'RACE primers. By overlapping the two partial cDNA sequences obtained by 3' and 5' RACE, their full-length sequence were obtained. All of the cDNAs of the six cDNAs composed of 5'UTR, open reading frame (ORF) and 3'UTR. The ORF encode a precursor including a potential signal peptide, a mature toxin and an intervening pro region.The prepro regions of HWTX-III and HWTX-IIIa, by the comparison of the cDNA sequences, were demonstrated to have high similarity with the prepro sequences of HWTX-I, SHL-I, HWTX-IV and HWTX-V. These peptides belong to a superfamily. The whole cDNA of HWTX-XI is different from that of other huwentoxins that we have identified previously and belongs to a new cDNA family.The cDNA sequences of JZTX have low similarity. The additional amino acid residues in the C terminal of the precursors indicate that the carboxyl terminal of JZTX-XI and JZTX-V were amidated.Spider venom contains a variety of toxic peptide components. These toxins have broader applications in the field of neurobiology and pharmacology.