Oral bacterial metabolic enzymes and cell surface proteins

Zinc ions serve as multi-target antimicrobial agents within the oral cavity, affecting both the cell surface and intracellular processes of various bacterial species such as Streptococcus mutans and Porphyromonas gingivalis. Intracellularly, zinc primarily targets and inhibits key enzymes in the glycolytic pathway, most notably glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which halts the production of organic acids that lead to dental caries (He et al., 2002). On the cell surface, zinc ions interfere with bacterial adhesion and co-aggregation, preventing the maturation of dental plaque biofilms (Lynch, 2011). Zinc also inhibits bacterial proteases responsible for the degradation of sulfur-containing amino acids, thereby reducing the emission of volatile sulfur compounds associated with halitosis. Due to these diverse mechanisms, zinc salts like zinc citrate and zinc chloride are widely incorporated into oral care products to control plaque, gingivitis, and bad breath (Phan et al., 2004). The broad-spectrum activity of zinc ions makes them a cornerstone of non-prescription chemical plaque control.

Other names

Bacterial zinc targetsOral biofilm targetsZinc-sensitive bacterial proteinsZinc-binding bacterial enzymes

Zinc ions inhibit bacterial metabolism by binding to the thiol groups of essential glycolytic enzymes, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), thereby blocking the conversion of glucose to lactic acid (He et al., 2002). They also disrupt bacterial cell membranes and inhibit the activity of proteases and aminopeptidases, which reduces the production of volatile sulfur compounds (Lynch, 2011). Additionally, zinc ions compete with other essential metal ions for transport systems, further stressing bacterial homeostasis and inhibiting growth (Phan et al., 2004).