Prokaryotic tungsten-containing enzymes (W-enzymes) (W-enzymes)

Prokaryotic tungsten-containing enzymes, also known as tungstoenzymes, are a unique class of oxidoreductases that utilize a tungsten-pterin cofactor to facilitate complex redox transformations (Kletzin & Adams, 1996). These enzymes are predominantly found in anaerobic bacteria and archaea, where they play vital roles in carbon metabolism, such as the reduction of carboxylic acids and the oxidation of formate (Bevers et al., 2009). In certain human pathogens, such as Campylobacter jejuni, these enzymes are essential for energy conservation and colonization within the host environment (Smart et al., 2009). Because tungsten-dependent metabolism is virtually absent in humans—who rely on molybdenum for similar catalytic roles—these enzymes are considered attractive targets for the development of narrow-spectrum antimicrobial agents (Johnson et al., 1996). Potential therapeutic strategies involve the use of tungstate analogs or small molecules that disrupt the transport and incorporation of the tungsten metal into the enzyme's active site (L'vov et al., 2002). However, a significant challenge in targeting these enzymes is ensuring selectivity to prevent the inhibition of human molybdenum-containing enzymes, which share structural similarities with their tungsten counterparts (Hille, 2002). Current research focuses on understanding the specific coordination chemistry of the tungsten site to design inhibitors that exploit the subtle differences between tungsten and molybdenum biochemistry (Sigel & Sigel, 2002).

Other names

TungstoenzymesTungsten-dependent enzymesW-containing oxidoreductasesTungsten-containing proteins

Competitive inhibition of the tungstate transporter (e.g., TupA) or the substitution of tungsten with molybdenum in the active site, which often results in a loss of catalytic activity in tungsten-obligate enzymes (Bevers et al., 2006; L'vov et al., 2002).