Plasmodium vivax: Molecular cloning, expression and characterization of glutathione S-transferase

• Published in: Experimental parasitology 2007-08, Vol.116 (4), p.414-418
• Main Authors: Na, Byoung-Kuk, Kang, Jung-Mi, Kim, Tong-Soo, Sohn, Woon-Mok
• Format: Article
• Language: English
• Subjects: 1,2-dichloro-4-nitrobenzene; 1-chloro-2,4-dinitrobenzene; Amino Acid Sequence; Animals; Biological and medical sciences; CDNB; CHP; Cloning, Molecular; cumene hydroperoxide; DCNB; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic; glutathione; glutathione peroxidase; glutathione S-transferase; Glutathione Transferase - chemistry; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; GPx; GSH; GST; Humans; IPTG; isopropyl-1-thio-β-d-galactopyranoside; Life cycle. Host-agent relationship. Pathogenesis; Malaria; Malaria, Vivax - parasitology; Molecular Sequence Data; nickel–nitrilotriacetic acid; Ni–NTA; Plasmodium falciparum; Plasmodium vivax; Plasmodium vivax - enzymology; Plasmodium vivax - genetics; Protozoa; recombinant P. vivax GST; rPvGST; Sequence Alignment; Substrate Specificity
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2007.02.005

Malaria parasite glutathione S-transferases (GSTs) are postulated to be essential for parasite survival by protecting the parasite against oxidative stress and buffering the detoxification of heme-binding compounds; therefore, GSTs are considered potential targets for drug development. In this study, we identified a Plasmodium vivax gene encoding GST (PvGST) and characterized the biochemical properties of the recombinant enzyme. The PvGST contained 618 bp that encoded 205 amino acids and shared a significant degree of sequence identity with GSTs from other Plasmodium species. The recombinant homodimeric enzyme had an approximate molecular mass of 50kDa and exhibited GSH-conjugating and GSH–peroxidase activities towards various model substrates. The optimal pH for recombinant PvGST (rPvGST) activity was pH 8.0, and the enzyme was moderately unstable at 37°C. The Km values of rPvGST with respect to GSH and CDNB were 0.17±0.09 and 2.1±0.4mM, respectively. The significant sequence homology and similar biochemical properties of PvGST and Plasmodium falciparum GST (PfGST) indicate that they may have similar molecular structures. This information may be useful for the design of specific inhibitors for plasmodial GSTs as potential antimalarial drugs.