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Characterization of an eukaryotic peptide deformylase from Plasmodium falciparum
V Bracchi-Ricard1, K T Nguyen, Y Zhou
1Department of Molecular Biology & Microbiology, University of Central Florida, Orlando, FL 32816, USA.
Abstract:
Ribosomal protein synthesis in eubacteria and eukaryotic organelles initiates with an N-formylmethionyl-tRNA(i), resulting in N-terminal formylation of all nascent polypeptides. Peptide deformylase (PDF) catalyzes the subsequent removal of the N-terminal formyl group from the majority of bacterial proteins. Until recently, PDF has been thought as an enzyme unique to the bacterial kingdom. Searches of the genomic DNA databases identified several genes that encode proteins of high sequence homology to bacterial PDF from eukaryotic organisms. The cDNA encoding Plasmodium falciparum PDF (PfPDF) has been cloned and overexpressed in Escherichia coli. The recombinant protein is catalytically active in deformylating N-formylated peptides, shares many of the properties of bacterial PDF, and is inhibited by specific PDF inhibitors. Western blot analysis indicated expression of mature PfPDF in trophozoite, schizont, and segmenter stages of intraerythrocytic development. These results provide strong evidence that a functional PDF is present in P. falciparum. In addition, PDF inhibitors inhibited the growth of P. falciparum in the intraerythrocytic culture.
Insights
Peptide deformylase (PDF) removes N-terminal formyl groups from proteins. This study found a functional PDF in Plasmodium falciparum (PfPDF), an important malaria parasite, and showed PDF inhibitors halt its growth.
Area of Science:
- Biochemistry
- Molecular Biology
- Parasitology
Background:
- Protein synthesis in bacteria and organelles begins with N-formylmethionyl-tRNA(i), leading to N-terminal formylation of nascent polypeptides.
- Peptide deformylase (PDF) is crucial for removing the N-terminal formyl group from most bacterial proteins.
- Previously, PDF was considered exclusive to bacteria, but recent genomic searches revealed homologous genes in eukaryotes.
Purpose of the Study:
- To investigate the presence and function of Peptide deformylase (PDF) in the malaria parasite Plasmodium falciparum.
- To determine if Plasmodium falciparum PDF (PfPDF) is a potential drug target.
Main Methods:
- Cloning and overexpression of Plasmodium falciparum PDF (PfPDF) cDNA in Escherichia coli.
- Biochemical assays to assess the catalytic activity of recombinant PfPDF.
- Western blot analysis to detect PfPDF expression during intraerythrocytic development.
- Testing the effect of PDF inhibitors on P. falciparum growth in culture.
Main Results:
- Recombinant PfPDF was successfully expressed and demonstrated catalytic activity in deformylating N-formylated peptides.
- PfPDF exhibited properties similar to bacterial PDF and was susceptible to specific PDF inhibitors.
- Mature PfPDF was detected in various intraerythrocytic developmental stages of P. falciparum.
- Inhibition of PDF activity significantly impeded the growth of P. falciparum in culture.
Conclusions:
- A functional Peptide deformylase (PDF) is present in Plasmodium falciparum.
- PfPDF represents a viable drug target for antimalarial therapies, as demonstrated by the efficacy of PDF inhibitors against parasite growth.