Silva Edelyn C N, Camargos Thalita S, Maranhão Andrea Q, Silva-Pereira Ildinete, Silva Luciano P, Possani Lourival D, Schwartz Elisabeth F
Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
Toxicon. 2009 Sep 1;54(3):252-61. doi: 10.1016/j.toxicon.2009.04.010. Epub 2009 Apr 18.
Scorpion venom glands produce a large variety of bioactive peptides. This communication reports the identification of venom components obtained by sequencing clones isolated from a cDNA library prepared with venomous glands of the Brazilian scorpion Opisthacanthus cayaporum (Ischnuridae). Two main types of components were identified: peptides with toxin-like sequences and proteins involved in cellular processes. Using the expressed sequence tag (EST) strategy 118 clones were identified, from which 61 code for unique sequences (17 contigs and 44 singlets) with an average length of 531 base-pairs (bp). These results were compared with those previously obtained by the proteomic analysis of the same venom, showing a considerable degree of similarity in terms of the molecular masses expected and DNA sequences found. About 36% of the ESTs correspond to toxin-like peptides and proteins with identifiable open reading frames (ORFs). The cDNA sequencing results also show the presence of sequences whose putative products correspond to a scorpine-like component; three short antimicrobial peptides; three K(+)-channel blockers; and an additional peptide containing 78 amino acid residues, whose sequence resembles peptide La1 from another Ischnuridae scorpion Liocheles australiasiae, thus far with unknown function.
蝎毒腺能产生多种生物活性肽。本通讯报道了从巴西蝎子Opisthacanthus cayaporum（异蝎科）毒腺制备的cDNA文库中分离出的克隆进行测序后所鉴定出的毒液成分。鉴定出了两种主要类型的成分：具有毒素样序列的肽和参与细胞过程的蛋白质。采用表达序列标签（EST）策略鉴定出118个克隆，其中61个编码独特序列（17个重叠群和44个单拷贝），平均长度为531个碱基对（bp）。将这些结果与之前对同一种毒液进行蛋白质组分析所得到的结果进行比较，发现在预期分子量和所发现的DNA序列方面有相当程度的相似性。约36%的EST对应于具有可识别开放阅读框（ORF）的毒素样肽和蛋白质。cDNA测序结果还显示存在一些序列，其推定产物对应于一种蝎毒素样成分；三种短抗菌肽；三种钾离子通道阻滞剂；以及一种含有78个氨基酸残基的额外肽，其序列类似于另一种异蝎科蝎子澳大利亚滑螯蝎的肽La1，目前功能未知。
