Background and aim: Brucellosis (Malta fever) is a zoonosis caused by ingestion of unpasteurized milk from infected animals, or close contact with their secretions. It leads to serious problems in global health, especially in underdeveloped countries. Brucellosis is caused by several species of the genus Brucella; a Gram-negative, facultative intracellular pathogen, which occurs worldwide. Due to the lack of efficient treatment against brucellosis, the only strategy is vaccination, which consists of conventional approaches or next generation one, including recombinant proteins. Choosing the suitable antigen stimulating the immune system is critical in preparation of these vaccines. Methods: The aim of this research is to pinpoint potential multi-epitope vaccine options, utilizing the genes RplL and BMEI0257, encoding Large ribosomal subunit protein bL12 and 4-hydroxyproline epimerase in B. melitensis, respectively. The CLC Protein Workbench was used to analyze physicochemical characteristics. Multiple alignment was performed by COBALT. PHYRE2 was used to predict protein 3D structures, which were then modeled and compared to homologous structures found in Uniprot. Results: Results of this study suggest that RplL and BMEI0257 are composed of 124 amino acids and 333 amino acids, respectively. The instability indices were 18.55 and 32.83, respectively. The hydrophilicity values were 0.119 and -0.190, respectively. In the secondary structure of RplL and BMEI0257 proteins, the α helix accounted for 47% and 17% the Beta strand was 8% and 39%, and random coil was 23% and 1%, respectively. Multiple alignment of 8 pathogenic species indicate high conservation between homologues of both target genes among Brucella. Conclusion: Regard to significant conservation of both RplL and BMEI0257, Proteins within the Brucella genus, characterized by their hydrophobicity and specific physicochemical properties, suggest that these two genes hold potential as promising targets for the development of recombinant vaccines. Such vaccines could confer protection against various Brucella species.
