Insights from the analysis of a predicted model of gp63 in Leishmania donovani.

Leishmaniasis is a protozoal disease of human that occurs in most parts of the world. By considering the progress of bioinformatics in molecular modeling, major surface glycoprotein of Leishmania donovani (gp63) structure was modeled using homology modeling with high accuracy based on the X-ray crystal structure of the Leishmania major gp63 as a template, and then analyzed 3D structure of gp63 which can reveal exact facts about its structure and interaction. The objective of this study was to find folding and three dimensional structure of the gp63 as potent antigen for human. In this project, we applied the theory of evolution method, including comparative modeling and threading. This study presented a simple protocol for rapid and precise finding 3D structure of gp63 and investigation of its structural properties. The translated amino acid sequence showed that Leishmania donovani gp63 contains 590 amino acids precursor protein consisting of an NH(2)-terminal signal peptide of 39 amino acids for membrane targeting, a pro region of 48 amino acids, the mature protein of 478 amino acids containing glycosylation and putative catalytic sites, and a COOH-terminal signal peptide of 25 amino acids for GPI attachment. Based on our model, the protein consists of three domains: the N-terminal, central and C-terminal domains. Additionally, these results could guide future structure-function analyses of gp63 protein.