Leishmanolysin gp63: Bioinformatics evidences of immunogenic epitopes in Leishmania major for enhanced vaccine design against zoonotic cutaneous leishmaniasis

Abstract

Cutaneous leishmaniasis (CL) is a prevalent disease in the Old World territories especially in the underdeveloped countries of the Middle East. The present study was aimed at prediction of primary biochemical features of the Leishmania major gp63 as a vaccine candidate and its potent linear B-cell epitopes as well as those epitopes with highest binding capacity to mouse and human MHC molecules. A wide range of servers were employed for prediction of physico-chemical, antigenic and allergenic traits, post-translational modifications (PTM), transmembrane domain and subcellular localization, 2D and 3D structures, tertiary model rehashing and validations. The 63.95 kDa protein was antigenic, non-allergenic, hydrophilic and stable, with improved thermotolerance and 43 PTM sites. The secondary structure encompassed 48.67% random coil, 31.4% alpha helix and 19.93% extended strand. Ramachandran analysis of the refined model showed 98.5% and 100% of residues in favored and allowed regions, respectively. After epitope screening, two linear B-cell epitopes and a number of mouse and human MHC-specific epitopes were predicted, which possessed highest antigenic index. This paper provides insights into the bioinformatics characteristics of the L. major gp63 protein as a promising vaccine candidate.