Thiol-containing bacterial enzymes and proteins

Thiol-containing bacterial enzymes and proteins constitute a diverse group of essential molecules that utilize the reactive sulfhydryl (-SH) group of cysteine residues for catalytic activity, structural stability, and redox regulation. These targets include critical metabolic enzymes such as glyceraldehyde-3-phosphate dehydrogenase, as well as proteins involved in the bacterial respiratory chain and antioxidant defense systems like thioredoxin and various low-molecular-weight thiol-dependent enzymes (Jung et al., 2008). Because the thiol group is highly nucleophilic, it is susceptible to modification by various antimicrobial agents, including heavy metal ions (e.g., silver and mercury) and oxidizing agents (McDonnell & Russell, 1999). Interaction with these drugs typically results in the formation of stable mercaptides or disulfide bonds, leading to protein denaturation, loss of enzymatic function, and catastrophic failure of cellular homeostasis. This broad-spectrum mechanism is a hallmark of many traditional antiseptics and disinfectants used to treat or prevent bacterial infections. However, the lack of high specificity for bacterial thiols over host thiols often limits the systemic use of these agents, necessitating careful consideration of their therapeutic index (Fahey, 2013).

Other names

Bacterial sulfhydryl-containing proteinsCysteine-containing bacterial enzymesBacterial protein thiolsBacterial thiol-dependent enzymes

Covalent binding or oxidation of sulfhydryl (-SH) groups on cysteine residues, leading to protein denaturation, inactivation of essential enzymes, and disruption of the bacterial respiratory chain (McDonnell & Russell, 1999; Jung et al., 2008).