Antibacterial Mechanism of Bacteriolyses of Bacterial Cell Walls by Zinc(Ⅱ) Ion Induced Activations of PGN Autolysins, and DNA damages
Bacteriolyses and destructions of bacterial cell walls by zinc (Ⅱ) ion solutions were investigated against Staphylococcus aureus and Escherichia coli. Bacteriolysis of S. aureus peptidoglycan (PGN) cell wall by zinc ion solution is due to the inhibition of PGN elongation by the activations of PGN autolysins of amidases. The other, bacteriolysis and destruction of E. coli cell wall are caused by the destruction of outer membrane structure due to degradative enzymes of lipoproteins at N- and C-terminals, and also inhibition of PGN elongation is dependent on the activities of PGN hydrolases and autolysins of amidase and carboxypeptidase-transpeptidase. Zinc ions induced ROS such as O2－, H2O2, ･OH, OH－producing in bacterial cell wall occur oxidative stress. DNA damages may be due to Zn ion complex formation by Zn2+ substitution into hydrogen bonds in DNA base pairs.