DNA APTAMERS SPECIFICALLY BINDING TO PLASMODIUM FALCIPARUM GLUTAMATE DEHYDROGENASE (PFGDHA)

摘要

The present invention relates to development of ssDNA aptamer with high affinity and specificity against Plasmodium falciparum glutamate dehydrogenase and it is useful for malaria detection. ssDNA aptamer is a short and single stranded (ss) oligonucleotides capable of recognizing target molecule with high affinity. Here we developed ssDNA aptamer ID NG3, NG51 that bind with Plasmodium falciparum glutamate dehydrogenase (PfGDH), one of the important malarial biomarker. Aptamers were selected by SELEX process from 10 12-15 random libraries of 40 mer ssDNAs. The selected aptamer specifically bind to PfGDHa but not to the structurally similar protein such as human glutamate dehydrogenase as well other parasitic enzyme Plasmodium falciparum histidine rich protein-II (PfHRP-II), Plasmodium falciparum lactate dehydrogenase (PfLDH). The Kd value (Dissociation constant) were calculated for developed aptamer NG3 and NG51 it found 0.5±0.04 µM and 1.1±0.2 µM, respectively. The secondary structure and δG value of aptamer were predicted through mfold which reveal that both aptamers have stem loop structure and the corresponding δG value are 7.99 and 4.68 kcal/mole respectively. The novel aptamer PfGDHa can be further applied to high specificity detection platform for diagnosis of malaria.