Exploring the novel protein drug target BAG33339.1 of Porphyromonas gingivalis: an integrative subtractive proteomics and structural dynamics study.

Abstract

Porphyromonas gingivalis, a gram-negative, bacterium interacts favourably with host subgingival biofilms to cause adult tooth decay and loss. Consequently, the host is infested with an uncontrollable microbial community and a compromised immune system, ultimately leading to tissue damage and bone resorption. P. gingivalis has also been known to cause cardiovascular and metabolic diseases, Alzheimer's disease, depression, prostate and digestive system cancer, rheumatoid arthritis, and adverse pregnancy outcomes with high detection frequencies. Rising concerns in the recent past, highlight the inefficiency of antibiotics and antiseptics in the treatment of P. gingivalis-related infections. Hence, the current scenario impels the discovery of an alternative therapeutic avenue against P. gingivalis-infections. To elucidate the unidentified bacterial mechanisms of infection, we screened a non-homolog of the host and gut microbiome as a novel druggable target from 173 essential hypothetical proteins of P.gingivalis (BAG33339.1). BAG33339.1 was an inner membrane protein with a hydrophobic N-terminal transmembrane helix and a primarily reconfiguring C-terminal helical region (Y36 to E52) while the residues (downstream of Lys45) lay in the disordered region. Frustration index coupled with the mutation matrix showed the steadiness of the transmembrane helix and dynamicity of the C-terminal residues finally yielding a 'U'-shaped protein conformation. The tendency of the disordered C-terminal residues was to generate P. gingivalis variants. The overall conformational stability was determined by equilibrating RMSD, R_g and SASA values corroborated by increasing H-bonds and helix settling. Targeting the ligand binding pockets of BAG33339.1 would guide future endeavours to tackle P. gingivalis interaction with host systems.