Miranda Mariana R, Canepa Gaspar E, Bouvier León A, Pereira Claudio A
Laboratorio de Biología Molecular de Trypanosoma cruzi, Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires and CONICET, Av. Combatientes de Malvinas 3150, 1427 Capital Federal, Buenos Aires, Argentina.
Exp Parasitol. 2008 Sep;120(1):103-7. doi: 10.1016/j.exppara.2008.04.017. Epub 2008 May 1.
Nucleoside diphosphate kinases (NDPKs) are multifunctional enzymes involved mainly in the conservation of nucleotides and deoxynucleotides at intracellular levels. Here we report the characterization of two NDPKs from the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease. TcNDPK1 and TcNDPK2 were biochemically characterized presenting different kinetic parameters and regulation mechanisms. NDPK activity was mainly detected in soluble fractions according to the digitonin extraction technique; however 20% of the activity remains insoluble at digitonin concentrations up to 5 mg ml(-1). TcNDPK1 is a short enzyme isoform, whereas TcNDPK2 is a long one containing a DM10 motif. In addition, two other putative NDPK genes (TcNPDK3 and TcNDPK4) were detected by data mining at the T. cruzi genome database. The large number and diversity of NDPK isoforms are in agreement with those previously observed for other T. cruzi phosphotransferases, such as adenylate kinases.
核苷二磷酸激酶（NDPK）是多功能酶，主要参与细胞内核苷酸和脱氧核苷酸的保存。在此，我们报告来自原生动物寄生虫克氏锥虫（恰加斯病的病原体）的两种NDPK的特性。对TcNDPK1和TcNDPK2进行了生化特性分析，它们呈现出不同的动力学参数和调节机制。根据洋地黄皂苷提取技术，NDPK活性主要在可溶性部分检测到；然而，在洋地黄皂苷浓度高达5 mg/ml时，仍有20%的活性不溶解。TcNDPK1是一种短酶异构体，而TcNDPK2是一种长酶异构体，含有一个DM10基序。此外，通过在克氏锥虫基因组数据库中进行数据挖掘，检测到另外两个假定的NDPK基因（TcNPDK3和TcNDPK4）。NDPK异构体的大量存在和多样性与先前在其他克氏锥虫磷酸转移酶（如腺苷酸激酶）中观察到的情况一致。
