Bacterial sulfur- and phosphorus-containing proteins and enzymes

Bacterial sulfur- and phosphorus-containing proteins and enzymes represent a broad class of intracellular targets for antimicrobial agents, most notably silver ions and silver nanoparticles (Prabhu & Poulose, 2012). These targets include essential respiratory enzymes, such as NADH dehydrogenase, where silver ions bind to thiol (-SH) groups, causing protein denaturation and the collapse of the proton motive force (Jung et al., 2008). Beyond enzymes, silver interacts with phosphorus-containing moieties in bacterial DNA and RNA, leading to structural condensation and the inhibition of replication and transcription (Rai et al., 2009). This multi-target mechanism of action is highly effective against a wide range of Gram-positive and Gram-negative bacteria, as well as some fungi (Slavin et al., 2017). Because silver affects multiple vital pathways simultaneously, the development of bacterial resistance is significantly more complex than with single-target antibiotics. Clinically, these interactions are exploited in topical treatments for burns and chronic wounds to prevent and treat infections.

Other names

Bacterial thiol-containing proteinsSulfur-containing respiratory enzymesPhosphorus-containing intracellular bacterial moleculesBacterial Ag+ targetsBacterial respiratory enzymes and other intracellular proteins containing sulfur/phosphorus groups

Silver ions interact with thiol (-SH) groups in bacterial enzymes, particularly those involved in the respiratory chain, leading to protein denaturation and enzymatic inactivation (Jung et al., 2008). Additionally, silver ions bind to phosphorus-containing groups in DNA and RNA, inhibiting replication and transcription processes (Prabhu & Poulose, 2012).