Campetella O, Henriksson J, Aslund L, Frasch A C, Pettersson U, Cazzulo J J
Instituto de Investigaciones Bioquímicas Fundación Campomar, CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Mol Biochem Parasitol. 1992 Feb;50(2):225-34. doi: 10.1016/0166-6851(92)90219-a.
We demonstrate that cruzipain, the major cysteine proteinase of Trypanosoma cruzi epimastigotes, is encoded by a large number of tandemly arranged genes. Restriction enzyme analysis of 20 clones containing complete repeat units of the gene, as well as sequencing of 2 of these clones, and comparison with previously published partial sequences, indicated that the sequence is conserved among the repeat units, although polymorphisms clearly exist. The repeat units contain an intergenic region of 528 bp and coding regions for pre- and pro-enzyme, a central domain and a C-terminal extension. The predicted amino acid sequences of these regions indicated a sequence identity of 30, 60, 70 and 36%, respectively, when the T. cruzi sequence was compared with the sequence of a similar cysteine proteinase from Trypanosoma brucei. Studies by pulsed field gel electrophoresis, complemented with restriction analysis, indicated that the clusters are located on 2-4 different chromosomes in several parasite isolates.
我们证明，克氏锥虫前鞭毛体的主要半胱氨酸蛋白酶克氏锥虫蛋白酶由大量串联排列的基因编码。对包含该基因完整重复单元的20个克隆进行限制性酶切分析，以及对其中2个克隆进行测序，并与先前发表的部分序列进行比较，结果表明，尽管明显存在多态性，但该序列在重复单元之间是保守的。重复单元包含一个528 bp的基因间隔区以及前酶和酶原、一个中央结构域和一个C末端延伸区的编码区。当将克氏锥虫的序列与来自布氏锥虫的类似半胱氨酸蛋白酶的序列进行比较时，这些区域的预测氨基酸序列的序列同一性分别为30%、60%、70%和36%。脉冲场凝胶电泳研究辅以限制性分析表明，在几种寄生虫分离株中，这些基因簇位于2 - 4条不同的染色体上。
