Insights into the interaction of key biofilm proteins in Pseudomonas aeruginosa PAO1 with TiO nanoparticle: An in silico analysis.

Pseudomonas aeruginosa is a pathogenic biofilm forming bacteria which exist in wide range of environments such as water, soil and human body. In an earlier study, we used a system biology approach based analysis of biofilm forming genes of P. aeruginosa and their possible role in TiO nanoparticle binding. The major protein of P. aeruginosa targeted by TiO was found to be KatA, a major catalase required for HO resistance and acute virulence and the direct interacting protein partners of KatA were found to be DnaK, Hfq, RpoA and RpoS. To understand the protein-protein physical interaction characteristic of these key proteins involved in biofilm related processes, homology modeling, docking and molecular dynamic simulation were performed. For all these proteins, physical and chemical properties, amino acid composition, nest and cleft analysis were performed using online tools. The interactions between TiONPs-KatA and four protein-protein complexes such as KatA-DnaK, KatA-Hfq, KatA-RpoA and KatA-RpoS were studied. Our results indicate that all four key proteins and TiONPs can have stable complexation with KatA. The study has given enough clues to understand the interaction of TiONPs with P. aeruginosa biofilm in natural environment. Further investigations could lead to development of TiONPs based therapeutic and sanitary interventions to combat this pathogenic bacterium.