Pellegrin J L, Ortega-Barria E, Prioli R P, Meijia J S, Pereira M E
Clinique de Medicine Interne, Hopital Haut-Leveque, Pessac, France.
Trop Med Parasitol. 1992 Mar;43(1):33-7.
We have recently reported the presence of neuraminidase (NA) activity in Acanthamoeba castellanii. We now show that the NAs of T. cruzi and A. castellanii share cross-reactive determinants using TCN-2, a monoclonal antibody (mAb) against the T. cruzi NA and a mouse polyclonal Ab (anti-TR) raised against a tandemly repeated dodecapeptide which contains the epitope recognized by TCN-2 (Prioli et al., submitted). This cross-reactivity was demonstrated by the reaction of TCN-2 and anti-TR with A. castellanii parasites using immunofluorescence, immunoblotting and ELISA. Inhibition and immunoprecipitation of enzyme activity confirmed that the A. castellanii antigen recognized by TCN-2 was the NA. Immunoprecipitation of [35S] labeled trophozoite lysates showed the A. castellanii NA to have a molecular weight of 115 kDa. In addition, immunoblot analysis of subcellular fractions obtained by ultracentrifugation showed the A. castellanii NA to be associated with the parasite membrane but not with the cytosol or cytoskeleton fractions. These results suggest that the TCN-2 epitope, contained within a dodecamer tandem repeat unit, is present in T. cruzi and A. castellanii NAs.
我们最近报道了卡氏棘阿米巴中存在神经氨酸酶（NA）活性。现在我们利用TCN - 2（一种针对克氏锥虫NA的单克隆抗体（mAb））和一种针对包含被TCN - 2识别的表位的串联重复十二肽产生的小鼠多克隆抗体（抗TR），证明克氏锥虫和卡氏棘阿米巴的NA具有交叉反应性决定簇（Prioli等人，已提交）。通过免疫荧光、免疫印迹和酶联免疫吸附测定法，利用TCN - 2和抗TR与卡氏棘阿米巴寄生虫的反应证实了这种交叉反应性。酶活性的抑制和免疫沉淀证实被TCN - 2识别的卡氏棘阿米巴抗原是NA。对[35S]标记的滋养体裂解物进行免疫沉淀显示，卡氏棘阿米巴的NA分子量为115 kDa。此外，对超速离心获得的亚细胞组分进行免疫印迹分析表明，卡氏棘阿米巴的NA与寄生虫膜相关，但与胞质溶胶或细胞骨架组分无关。这些结果表明，存在于十二聚体串联重复单元中的TCN - 2表位存在于克氏锥虫和卡氏棘阿米巴的NA中。
