Investigating reactive oxygen species triggered damage to cell teichoic acid via molecular dynamics

In this study, we investigated the mechanisms by which reactive oxygen species (ROS) cause oxidative damage to wall teichoic acid (WTA) and lipoteichoic acid (LTA) in two bacterial species: Staphylococcus aureus and Streptococcus pneumoniae. Using molecular dynamics simulations, we found that ROS primarily induce structural damage through dehydrogenation reactions and the cleavage of C-C and C-O bonds. Notably, the teichoic acid (TA) from S. aureus was found to be more susceptible to damage compared to that of S. pneumoniae, which exhibited stronger antioxidant properties due to its ring structure and chemical modifications. The efficiency of damage increased with ROS concentration, following the order, O > O3 > OH, with a maximum of 22.22% C-C bond cleavage observed at the highest concentration. In addition, the patterns of damage in the TA of these two bacterial species were significantly different. In S. aureus, WTA damage was predominantly characterized by C-C and C-O bond cleavage in the repeating units, whereas LTA damage was primarily due to the cleavage of C-C bonds in the ring structure. In S. pneumoniae, damage to both WTA and LTA mainly occurred at the N-acetylglucosamine (GlcNAc) ring structure and the poly (RboP) site. This study offers new insights into the sterilizing effects of plasma.