Creaney J, Wijffels G L, Sexton J L, Sandeman R M, Spithill T W, Parsons J C
Victorian Institute of Animal Science, Department of Agriculture, Australia.
Exp Parasitol. 1995 Aug;81(1):106-16. doi: 10.1006/expr.1995.1098.
Four cDNA clones (GST-1, -7, -47, and -51) encoding isoenzymes of the detoxification enzyme glutathione S-transferase (GST) have previously been identified and characterised from Fasciola hepatica. In the present study, antisera were generated to synthetic peptides of regions unique to each of the four GST proteins predicted by the cDNAs. The antisera were characterised, and two were found to distinguish GST-1 from GST-7, GST-47, and GST-51 as a group. These two antisera were used to localise different GSTs in adult and newly excysted juvenile F. hepatica. The antiserum to GST-1 was specific and localised GST-1 to the parenchyma of adult fluke but not to the lamellae of the intestinal caeca. The antiserum to a GST-51 peptide, which cross-reacted with GST-7 and GST-47 but not GST-1, localised the other GSTs not only to the parenchyma but also to the intestinal lamellae of adult fluke. This appears to be the first evidence of tissue-specific expression of GST isoenzymes in trematodes. In contrast to adult fluke, immunolocalisation of the GSTs in juvenile F. hepatica revealed the binding of both the GST-1 and GST-51 antisera to the parenchymal cytoplasm, to cytoplasmic extensions of the parenchyma cells in the subtegumental area, as well as the excretory ducts. No labeling was observed in the intestinal epithelium of the juvenile fluke. These results demonstrate that adult F. hepatica, in contrast to juvenile flukes, contain a GST, which is not GST-1, associated with the lamellae of the gut and suggest that GSTs in adult fluke may play a role in the absorptive function of the adult gut.
先前已从肝片吸虫中鉴定并表征了四个编码解毒酶谷胱甘肽S-转移酶（GST）同工酶的cDNA克隆（GST-1、-7、-47和-51）。在本研究中，针对由cDNA预测的四种GST蛋白各自特有的区域合成肽产生了抗血清。对这些抗血清进行了表征，发现其中两种抗血清可将GST-1与GST-7、GST-47和GST-51作为一个组区分开来。这两种抗血清用于在成年和新脱囊的幼年肝片吸虫中定位不同的GST。针对GST-1的抗血清具有特异性，将GST-1定位在成年吸虫的实质组织中，但未定位在肠盲囊的薄片中。针对GST-51肽的抗血清与GST-7和GST-47发生交叉反应，但与GST-1不发生交叉反应，它不仅将其他GST定位在成年吸虫的实质组织中，还定位在成年吸虫的肠薄片中。这似乎是吸虫中GST同工酶组织特异性表达的首个证据。与成年吸虫不同，幼年肝片吸虫中GST的免疫定位显示，GST-1和GST-51抗血清均与实质细胞质、皮下区域实质细胞的细胞质延伸以及排泄管结合。在幼年吸虫的肠上皮中未观察到标记。这些结果表明，与幼年吸虫相比，成年肝片吸虫含有一种与肠道薄片相关的GST，而不是GST-1，并表明成年吸虫中的GST可能在成年肠道的吸收功能中起作用。
