Sharma S, Misra S, Rathaur S
Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India.
Trop Med Int Health. 1998 Jan;3(1):46-51. doi: 10.1046/j.1365-3156.1998.00171.x.
Setaria cervi, a bovine filarial parasite, secretes acetylcholinesterase during in vitro cultivation. A significant amount of enzyme activity was detected both in culture media and somatic extracts of different developmental stages of the parasite. The microfilarial stage showed a higher level of AChE activity than adult worms, with females being considerably more active than males. The secretory enzyme from microfilariae preferentially utilized acetylthiocholine iodide as substrate and showed two electrophoretically distinct isoforms in native PAGE. Secretory enzyme was purified from the excretory/secretory products of microfilariae using edrophonium chloride linked to epoxy-activated sepharose. Analysis of purified acetylcholinesterase by SDS-PAGE revealed the existence of two proteins of 75kD and 45kD under nonreducing conditions. These secretory enzymes are antigenic and cross-reactive with Wuchereria bancrofti-infected asymptomatic microfilaraemic human sera when tested by enzyme linked immunosorbent assay and immunoblotting. The secretory AChE(s) from S. cervi microfilariae may be utilized for diagnosis of early filarial infections.
牛丝状寄生虫鹿丝状线虫（Setaria cervi）在体外培养过程中会分泌乙酰胆碱酯酶。在该寄生虫不同发育阶段的培养基和虫体提取物中均检测到了大量的酶活性。微丝蚴阶段的乙酰胆碱酯酶（AChE）活性水平高于成虫，其中雌性微丝蚴的活性明显高于雄性。微丝蚴分泌的酶优先利用碘化硫代乙酰胆碱作为底物，并且在非变性聚丙烯酰胺凝胶电泳（native PAGE）中显示出两种电泳性质不同的同工型。使用与环氧活化琼脂糖偶联的依酚氯铵从微丝蚴的排泄/分泌产物中纯化分泌酶。在非还原条件下，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）对纯化的乙酰胆碱酯酶进行分析，结果显示存在两种蛋白质，分子量分别为75kD和45kD。当通过酶联免疫吸附测定和免疫印迹法进行检测时，这些分泌酶具有抗原性，并且与感染班氏吴策线虫（Wuchereria bancrofti）的无症状微丝蚴血症患者血清存在交叉反应。鹿丝状线虫微丝蚴分泌的AChE可用于早期丝虫感染的诊断。
