In Vitro Measurement of Gas-Dependent and Redox-Sensitive Diguanylate Cyclase Activity

Bacteria sense and respond to gaseous ligand changes in the environment to regulate a multitude of behaviors, including the production of the secondary messengers cyclic di-GMP. Gas sensing can be difficult to measure due to the high concentration of the oxygen in the atmosphere, particularly in redox-sensitive systems. Here, we describe a method for anaerobic quantification of cyclic di-GMP production which can be used to measure the impact of molecular oxygen, nitric oxide, and carbon monoxide on the catalysis of a diguanylate cyclase-containing protein and the possible pitfalls in the experimental procedure.