Site-directed and random enzyme immobilization on functionalized membranes: kinetic studies and models

A Study of His-Tagged Alkaline Phosphatase Immobilization on a Nanoporous Nickel– Titanium Dioxide Film

“…This is consistent with the fact that the His-tag ALP may partially bind to Ni-TiO 2 with the same orientation that maximally exposes the active sites. This result is comparable with the literature, as Vishwanath and co-workers (17) reported that the activity of oriented immobilized enzyme is higher than that of the randomly immobilized enzyme. This is important for biosensor applications where the amount of available surface may be low and so high retention of catalytic activity is essential.…”

“…Interference could be due to the presence of chemical compounds (i.e., organometallic compounds) which induce the opening of a transition pore with consequent swelling even under nonenergized conditions (17). In this case, however, by operating in the presence of Cyclosporine, the inhibitor of the permeant pore, the interferences are excluded.…”

Controlled layer-by-layer immobilization of horseradish peroxidase

“…Finally, attachment through multiple residues may lead to crosslinking among and within the enzyme molecules, and to structural rigidity of the immobilized enzyme. The result of all these factors is a significant loss in the activity of the immobilized enzyme (Rao et al, 1998;Vishwanath et al, 1995;, which is not uncommon to be <20% of the activity of the same enzyme in solution.…”

Enzymatic membrane reactors: the determining factors in two separate phase operations

“…116 Membranes have high surface area for enzyme loads and provide strong covalent attachment. 117 In the TSP-EMR, the preferred method to immobilize the enzymes is adsorption through cross-flow filtration. This method recirculates an enzyme solution from one side to the other side of the HFM (shell-to lumen-side or the other way) causing the enzyme to adsorb to the membrane layers.…”