In silico mapping of Leptospira interrogans putative carboxypeptidases: functional domains, predicted virulence signatures, and epitope identification for potential subunit vaccine candidates

Leptospirosis, a widespread zoonotic disease caused by pathogenic spirochetes of the genus Leptospira , represents a severe global public health and economic burden. The pathogenic success of Leptospira relies on a complex repertoire of virulence factors, including proteases that facilitate tissue invasion, nutrient acquisition, and immune evasion. While carboxypeptidases play critical roles in bacterial cell wall maintenance and virulence in several pathogens, the functional and structural characteristics of these enzymes in Leptospira remain poorly understood. This study performed a comprehensive in silico characterization of nine predicted carboxypeptidases from Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130, evaluating physicochemical properties, subcellular localization, operon organization, and sequence conservation were evaluated. Additionally, functional domains were annotated, tertiary structures were modeled and virulence signatures, allergenic profiles, and T- and B-cell epitopes were systematically assessed. These in silico data suggest that L. interrogans putative carboxypeptidases are highly conserved and may play roles in host-pathogen interactions. Structural and immunogenic profiling indicates that LIC_12303 and LIC_13152 are potential candidates for the development of novel subunit vaccines against leptospirosis.