Molecular architecture of leishmania EF-1alpha reveals a novel site that may modulate protein translation: a possible target for drug development.
Elongation factor-1alpha plays an essential role in eukaryotic protein biosynthesis. Recently, we have shown by protein structure modeling the presence of a hairpin-loop of 12 amino acids in mammalian EF-1alpha that is absent in the leishmania homologue [D. Nandan, A. Cherkasov, R. Sabouti, T. Yi, N.E. Reiner, Molecular cloning, biochemical and structural analysis of elongation factor-1 alpha from Leishmania donovani: comparison with the mammalian homologue, Biochem. Biophys. Res. Commun. 302 (2003) 646-652]. As a consequence of this deletion, an exposed region is available on the main body of leishmania EF-1alpha. Here we report the generation of an anti-EF-1alpha antibody (DN-3) which bound selectively to the exposed region of leishmania EF-1alpha, with no reactivity with human EF-1alpha. In a leishmania cell-free protein translation system, DN-3 substantially inhibited protein translation. A similar inhibitory effect was observed when a specific peptide based on the exposed region was used in the cell-free protein translation assay. The application of structure-based in silico methods to identify potential ligands to target the exposed region identified a small molecule that selectively attenuated in vitro translation using leishmania extracts. Moreover, this small molecule showed selective suppressive effect on multiplication of leishmania in culture. Taken together, these findings identify a novel, exposed region in leishmania EF-1alpha that may be involved in protein synthesis and a potential site for drug targeting.
Lopez
Martin
M
Department of Medicine (Division of Infectious Diseases), University of British Columbia, Faculties of Medicine and Science, 2733 Heather Street, Heather Pavilion East, Room 452-D, Vancouver, BC, Canada V5Z 3J5.
Cherkasov
Artem
A
Nandan
Devki
D
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D016503:Drug Delivery Systems / Q000379:methods*; D015195:Drug Design; D007891:Leishmania / Q000378:metabolism*; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D014176:Protein Biosynthesis / Q000502:physiology*; D013329:Structure-Activity Relationship
D020648:Peptide Elongation Factor 1