Burkholderia pseudomallei γ-carbonic anhydrase is strongly activated by amino acids and amines

Activation of the γ-class carbonic anhydrase (CAs, EC 4.2.1.1) from the pathogenic bacterium Burkholderia pseudomallei (BpsγCA) with a series of natural and non-natural amino acids and aromatic/heterocyclic amines has been investigated. The best BpsγCA activators were D-His, L-DOPA, D-Trp, 4-amino-L-Phe, dopamine, 2-(2-aminoethyl)pyridine, 2-aminoethyl-piparazine/morpholine and L-adrenaline, which showed activation constants ranging between 9 and 86 nM. The least effective activators were L-His, L-Phe and 2-pyridyl-methylamine, with KAs in the range of 1.73–24.7 μM. As little is known about the role of γ-CAs in the lifecycle and virulence of this saprophytic bacterium, this study may shed some light on such phenomena. This is the first CA activation study of a γ-CA from a pathogenic bacterium, the only other such study being on the enzyme discovered in the archaeon Methanosarcina thermophila, Cam.