Subtractive Proteomic Approaches to Identify Drug Targets: An Analysis on Hypothetical Proteins of...

Pseudomonas aeruginosa is a Gram-negative pathogen responsible for nosocomial infections. The exploration of novel therapeutic targets within its proteome is essential for developing successful therapies for combating infections caused by this organism. Employing in silico approaches, this study aims to identify drug targets from hypothetical proteins of P. aeruginosa. These proteins were extracted from complete proteomes of 351 strains of P. aeruginosa after removing duplicates and taxonomically misclassified strains. The essentiality analysis revealed the presence of 1923 essential hypothetical proteins (EHPs) in these strains. These proteins were characterized based on physicochemical properties, subcellular locations, antimicrobial resistance, virulence and druggability. The domain analysis and functional annotation classified these as enzymes, transporters, and secretion proteins. Among these annotated proteins, 149 EHPs were found to be virulent proteins. The majority of these proteins are found to be involved in antibiotic inactivation and antibiotic efflux pumps. One hypothetical protein was characterized as a small multidrug resistance (SMR) efflux pump protein. Sixty-one EHPs were identified as potential drug targets, and 33 among these were identified in 15 different strains. The network analysis on these targets revealed a hub protein cobH, along with small clusters and singletons. These drug targets can be identified and validated experimentally before exploiting them in development of drugs against P. aeruginosa.