Liebau E, Eckelt V H, Wildenburg G, Teesdale-Spittle P, Brophy P M, Walter R D, Henkle-Dührsen K
Department of Biochemical Parasitology, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany.
Biochem J. 1997 Jun 1;324 ( Pt 2)(Pt 2):659-66. doi: 10.1042/bj3240659.
A recombinant glutathione S-transferase (GST) (EC 2.5.1.18) from the parasitic nematode Ascaris suum (AsGST1) displays specific activity with a variety of model substrates and secondary products of lipid peroxidation. The AsGST1 interacts with a range of model inhibitors, haematin-related compounds, bile acids and anthelminthics. The reported variations in biochemical activity correlate with structural differences observed by homology modelling. Here, differences in the topography of the proposed substrate binding site between the AsGST1 and the host GSTs were identified. A rabbit polyclonal antiserum was raised against the glutathione-binding proteins of A. suum and specific antibodies against AsGST1 were affinity-purified using the recombinant protein. These antibodies were used to localize the AsGST1 in adult worms by immunohistochemical staining. The strongest immunostaining for AsGST1 was localized in the intestine in all worms examined. This suggests that the enzyme may be responsible for the metabolism of materials that are incorporated from the environment, as well as for molecules that are excreted or secreted from the parasite to the environment. It also demonstrates the accessibility of the enzyme to an inhibitor or blocking antibody. In addition, the structure and sequence of the gene encoding AsGST1 have been determined. Southern-blot analyses of the AsGST1 gene suggests that it is a single-copy gene. The nucleotide sequence analysis revealed that the gene is composed of four exons and three introns, and potential regulatory elements were identified in the 5' flanking sequence.
来自寄生线虫猪蛔虫的重组谷胱甘肽S-转移酶（GST）（EC 2.5.1.18）（AsGST1）对多种模型底物和脂质过氧化的次级产物具有特异性活性。AsGST1与一系列模型抑制剂、血红素相关化合物、胆汁酸和驱虫药相互作用。报道的生化活性变化与同源建模观察到的结构差异相关。在此，确定了AsGST1与宿主GSTs之间拟议的底物结合位点的拓扑结构差异。制备了针对猪蛔虫谷胱甘肽结合蛋白的兔多克隆抗血清，并使用重组蛋白亲和纯化了针对AsGST1的特异性抗体。这些抗体用于通过免疫组织化学染色在成虫中定位AsGST1。在所检查的所有蠕虫中，AsGST1的最强免疫染色定位于肠道。这表明该酶可能负责从环境中摄取的物质的代谢，以及寄生虫排泄或分泌到环境中的分子的代谢。这也证明了该酶对抑制剂或阻断抗体的可及性。此外，还确定了编码AsGST1的基因的结构和序列。对AsGST1基因的Southern印迹分析表明它是一个单拷贝基因。核苷酸序列分析表明该基因由四个外显子和三个内含子组成，并且在5'侧翼序列中鉴定出潜在的调控元件。
