A useful propionate cofactor enhancing activity for organic solvent-tolerant recombinant metal-free bromoperoxidase (perhydrolase) from Streptomyces aureofaciens

The oxidative brominating activity of an organic solvent-tolerant recombinant metal-free bromoperoxidase BPO-A1 with C-terminal His-tag (rBPO-A1), from Streptomyces aureofaciens found to depend on various additives. These included carboxylic acids, used as cofactors and alcohols, used as water-miscible organic solvents. Enzyme activity was significantly enhanced by using propanoic acid (PA) as a cofactor, which had a high Log D at pH 5.0 and ethylene glycol with a low Log P. The positional specificity of oxidative hydroxybromination for olefins, using rBPO-A1 and PA in the presence of methanol, was higher compared to a non-enzymatic reaction using peracetic acid. The oxidative bromination step, occurring after enzymatic peroxidation step, is suggested to be pseudoenzymatic. •Activity of recombinat BPO-A1 is significantly enhanced by propoinate cofactor.•High regiospecificity of enzymatic oxidative hydroxybromination for olefins.•Competition of substrates and organic solvents in hydrophobic interaction with enzyme.•Important evidence for enzymatic contribution in the oxidative bromination step.