Britton C, Knox D P, Kennedy M W
Wellcome Laboratories for Experimental Parasitology, University of Glasgow, UK.
Parasitology. 1994 Aug;109 ( Pt 2):257-63. doi: 10.1017/s0031182000076381.
The presence of superoxide dismutase (SOD) activity in the bovine lungworm Dictyocaulus viviparus was examined using the xanthine-xanthine oxidase assay system and by non-denaturing PAGE followed by specific enzyme staining. High levels of activity were detected in excretory-secretory (ES) products of adult worms and in soluble extracts of both the L3 and adult stages of the parasite. Stage-specific and ES-specific activities were indicated by differences in SOD isoenzyme profiles between adult and larval parasite extracts and between adult extract and ES products, with a fast migrating activity being specific to ES products. All isoenzymes were sensitive to cyanide, indicating copper/zinc dependency. The antigenicity of ES SOD was demonstrated by a reduction in SOD activity in both the chemical assay and non-denaturing PAGE following incubation of parasite ES products with IgG antibody purified from serum of infected or vaccinated bovine hosts. The high level of SOD activity released by adult D. viviparus may be a reflection of the problems faced by a parasite occupying an oxygen-rich environment. Antibody inhibition of SOD may, therefore, be an important target of protective immunity.
利用黄嘌呤-黄嘌呤氧化酶检测系统并通过非变性聚丙烯酰胺凝胶电泳（PAGE）随后进行特异性酶染色，对牛肺线虫（胎生网尾线虫）中的超氧化物歧化酶（SOD）活性进行了检测。在成虫的排泄-分泌（ES）产物以及该寄生虫L3期和成虫期的可溶性提取物中均检测到了高水平的活性。成虫和幼虫寄生虫提取物之间以及成虫提取物与ES产物之间的SOD同工酶谱差异表明了阶段特异性和ES特异性活性，其中一种快速迁移的活性是ES产物特有的。所有同工酶对氰化物敏感，表明其依赖铜/锌。在用从感染或接种疫苗的牛宿主血清中纯化的IgG抗体孵育寄生虫ES产物后，化学检测和非变性PAGE中的SOD活性均降低，这证明了ES SOD的抗原性。胎生网尾线虫成虫释放的高水平SOD活性可能反映了寄生虫在富氧环境中面临的问题。因此，抗体对SOD的抑制作用可能是保护性免疫的一个重要靶点。
