Masake R A, Nantulya V M, Pellé R, Makau J M, Gathuo H, ole-MoiYoi O K
International Laboratory for Research on Animal Diseases (ILRAD), Nairobi, Kenya.
Mol Biochem Parasitol. 1994 Apr;64(2):207-18. doi: 10.1016/0166-6851(94)00011-5.
A monoclonal antibody that is used as a Trypanosoma vivax species-specific diagnostic reagent on antigen-trapping enzyme-linked immunosorbent assay recognized an 8-kDa peptide on western blots. The 8-kDa species-specific antigen was isolated and employed in raising rabbit polyclonal antibodies, which were used in the immunoscreening of a T. vivax cDNA library in lambda gt11.2. A clone containing a 0.8-kb insert was isolated. The cloned gene is tandemly repeated, with a monomeric unit length of 900 bp, in the genomes of all T. vivax isolates from diverse geographic locations in Africa and South America. The gene is differentially expressed, since both the transcript and antigen are present in bloodstream-stage parasites, but not in the epimastigotes of T. vivax. Although the gene is found in all T. vivax isolates so far tested, it either exists in low copy number or in a divergent form in one isolate from Kilifi at the Kenya Coast. Sequence translation revealed a remarkable degree of bias in codon usage with preference for G and C (82%) in the wobble position. Using the deduced amino acid sequence to search the databases for any structurally related peptides, revealed no significant identity with any known proteins. The function of the species-specific antigen of T. vivax is thus unknown. Nevertheless the identification and characterization of proteins released into the circulation of protozoan parasite-infected animals is important and should allow the determination of what role such molecules may play in the modulation of disease pathology.
一种在抗原捕获酶联免疫吸附测定中用作间日锥虫物种特异性诊断试剂的单克隆抗体，在蛋白质印迹法中识别出一种8 kDa的肽段。分离出该8 kDa的物种特异性抗原，并用于制备兔多克隆抗体，这些抗体用于对λgt11.2载体中的间日锥虫cDNA文库进行免疫筛选。分离出一个含有0.8 kb插入片段的克隆。该克隆基因在来自非洲和南美洲不同地理位置的所有间日锥虫分离株的基因组中呈串联重复，单体单元长度为900 bp。该基因存在差异表达，因为转录本和抗原都存在于血液阶段的寄生虫中，但在间日锥虫的前鞭毛体中不存在。尽管在迄今为止测试的所有间日锥虫分离株中都发现了该基因，但在肯尼亚海岸基利菲的一个分离株中，它要么以低拷贝数存在，要么以不同的形式存在。序列翻译显示密码子使用存在显著的偏向性，摆动位置优先使用G和C（82%）。利用推导的氨基酸序列在数据库中搜索任何结构相关的肽段，未发现与任何已知蛋白质有显著的同源性。因此，间日锥虫物种特异性抗原的功能尚不清楚。然而，鉴定和表征原生动物寄生虫感染动物循环中释放的蛋白质很重要，这应该有助于确定这些分子在调节疾病病理过程中可能发挥的作用。
