Epe C, Kohlmetz C, Schnieder T
Institute of Parasitology, Hannover School of Veterinary Science, Germany.
Parasitol Res. 1998 Sep;84(9):763-6. doi: 10.1007/s004360050484.
The objective of this study was to characterize a recombinant antigen of Ancylostoma caninum that had been identified by immunoscreening with selected antisera as described elsewhere. In vitro expression of clone Ac38-1 produced a protein with an apparent molecular mass of approximately 38 kDa, which reacted in Western blots with the antiserum from rabbits experimentally infected with L3 and also with affinity-purified antibodies against hydrophilic proteins of the cephalic glands obtained from the antiserum against the intestine, cephalic glands, and cervical glands of adult worms. It was recognized not by antisera from dogs percutaneously infected with 1,000 L3 of A. caninum but by antiserum from dogs infected with 100,000 L3 of A. caninum. DNA sequencing of clone Ac38-1 showed a cDNA fragment with a coding region of 1,014 bp. Comparison of clone Ac38-1 with the Genbank DNA data base revealed 78% identity with a 244-bp segment of the cm5b5 clone of the free-living nematode Caenorhabditis elegans coding for a protein disulfide isomerase gene. The deduced amino acid sequence of clone Ac38-1 showed 82% identity with a 334-amino-acid (aa) segment of the protein disulfide isomerase of C. elegans and 73% identity with a 334-aa segment of the protein disulfide isomerase aa sequence of Onchocerca volvulus.
本研究的目的是对犬钩口线虫的一种重组抗原进行特性分析，该重组抗原已通过如其他地方所述的用选定抗血清进行免疫筛选来鉴定。克隆Ac38-1的体外表达产生了一种表观分子量约为38 kDa的蛋白质，该蛋白质在蛋白质免疫印迹中与经L3实验感染的兔抗血清以及与从成虫肠道、头腺和颈腺抗血清中获得的针对头腺亲水性蛋白质的亲和纯化抗体发生反应。它不被经皮感染1000条犬钩口线虫L3的犬的抗血清所识别，但被感染100,000条犬钩口线虫L3的犬的抗血清所识别。克隆Ac38-1的DNA测序显示一个编码区为1014 bp的cDNA片段。将克隆Ac38-1与Genbank DNA数据库进行比较，发现与自由生活线虫秀丽隐杆线虫编码蛋白质二硫键异构酶基因的cm5b5克隆的一个244 bp片段有78%的同一性。克隆Ac38-1推导的氨基酸序列与秀丽隐杆线虫蛋白质二硫键异构酶的一个334个氨基酸（aa）片段有82%的同一性，与盘尾丝虫蛋白质二硫键异构酶aa序列的一个334 aa片段有73%的同一性。
