Improvement of hydrogenase enzyme activity by water-miscible organic solvents

Organic co‐solvents affect activity, stability and enantioselectivity of haloalkane dehalogenases

“…Despite the fact that most of the tested organic co‐solvents are strong denaturants of proteins [40], increase of DbjA activity was observed in nine different water/co‐solvent mixtures at low or moderate co‐solvent concentrations. Activation of enzymes by organic solvents has been previously observed with various enzymes, including lipase [41, 42], NADH oxidase [39], α‐chymotrypsin [43, 44], glyceraldehyde‐3‐phosphate dehydrogenase [45], neuraminidase [46], hydrogenase [47], Baeyer‐Villiger monooxygenase [48], carboxylesterase [49], and feruloyl esterase [50]. Several molecular mechanisms of enzyme activation by the action of organic solvents have been proposed: (i) small perturbations of the protein molecule induced by binding of co‐solvent molecules at the activation sites, (ii) removal of extraneous inhibitors from the active site by the co‐solvent, (iii) competition of the co‐solvent molecules acting as additional nucleophiles with water, (iv) increased affinity of the enzyme toward its substrates, (v) dissociation of oligomeric enzymes due to weakening of intersubunit interactions by co‐solvent, and (vi) the influence of the co‐solvent on the catalytic steps of enzymatic reactions [43, 46, 51].…”

pH‐Sensitive Water‐Soluble Nanospheric Imprinted Hydrogels Prepared as Horseradish Peroxidase Mimetic Enzymes

“…The catalytic efficiency of the imprinted catalyst can be estimated by the ratio of the values of V max and K m , [25,26] which Figure 3. The hydrodynamic particle size of imprinted microgels measured by dynamic light scattering.…”

Candida tenuis Xylose Reductase Catalyzed Reduction of Aryl Ketones for Enantioselective Synthesis of Active Oxetine Derivatives

“…30% v/v (Table ). Such approach is hence only applicable in laboratory scale, but for synthetic application in larger scale, the space/time yield is, however, by far too low …”

“…Such approach is hence only applicable in laboratory scale, but for synthetic application in larger scale, the space/time yield is, however, by far too low. 26 In another approach, we applied two-phase systems with a water non-miscible organic solvent containing the substrate as well as an aqueous buffer solution with the CtXR and the coenzyme. The organic layer is a reservoir for substrate and product, and the reaction occurs in aqueous medium.…”