Polyphosphate Kinase from <em>Burkholderia cenocepacia</em>, One Enzyme Catalyzing a Two Step Cascade Reaction to Synthesize ATP from AMP

ATP is an essential molecule in many biocatalytic processes. The industrial implementation of these processes is hampered by the fact that they require stoichiometric quantities of this expen-sive co-factor. To avoid this problem, recycling systems are needed. This study characterizes a putative polyphosphate kinase enzyme from Burkholderia cenocepacia that can regenerate ATP from AMP. Sequence analysis shows that BcPPK2-III exhibits the characteristic structural motifs of known PPK2 enzymes, including conserved motifs Walker A and B, and the subclass-specific res-idue E137. Molecular docking simulations showed ADP had the highest binding affinity (-7.340 kcal/mol), followed by AMP (-7.284 kcal/mol), with ATP having the lowest affinity (-6.464 kcal/mol). The enzyme was overexpressed in E. coli. Protein expression and purification were monitored by SDS-PAGE and quantified by densitometric analysis. Enzymatic activity assays re-vealed that BcPPK2-III converts 70% ATP with a TTN of 334,000 after 24 hours and remains sta-ble over a pH range of 6-9 and temperatures up to 70°C. BcPPK2-III shows significant potential for industrial ATP regeneration and offers high conversion rates and stability. The enzyme&#039;s high conversion rate and stability make BcPPK2-III a promising candidate for the improvement of bio-catalytic processes that rely on ATP at industrial level.