Pyrazinoic acid, the active form of the anti-tuberculosis drug pyrazinamide, and aromatic carboxylic acid analogs are protonophores.

Pyrazinoic acid is the active form of pyrazinamide, a first-line antibiotic used to treat infections. However, the mechanism of action of pyrazinoic acid remains a subject of debate, and alternatives to pyrazinamide in cases of resistance are not available. The work presented here demonstrates that pyrazinoic acid and known protonophores including salicylic acid, benzoic acid, and carbonyl cyanide -chlorophenyl hydrazone all exhibit pH-dependent inhibition of mycobacterial growth activity over a physiologically relevant range of pH values.

Proline Dehydrogenase and Pyrroline 5 Carboxylate Dehydrogenase from Evidence for Substrate Channeling.

In , proline dehydrogenase (PruB) and ∆-pyrroline-5-carboxylate (P5C) dehydrogenase (PruA) are monofunctional enzymes that catalyze proline oxidation to glutamate via the intermediates P5C and L-glutamate-γ-semialdehyde. Both enzymes are essential for the replication of pathogenic . Highly active enzymes were expressed and purified using a expression system.