Azlactone-reactive polymer supports for immobilizing synthetically useful enzymes: Part I. Pig liver esterase on dispersion polymer supports

Covalent attachment of pig liver esterase (E.C.3.1.1.1) to cross-linked dispersion polymer supports was effectively accomplished using azlactone [5(4H)-oxazolone] reactive groups. The binding process required about one hour at room temperature, and it was imperative that a relatively high concentration of a salt co-solute be present along with the enzyme. Under these conditions the enzyme rapidly bound onto the polymeric supports via hydrophobic interaction and then covalent attachment proceeded at effective rates. Up to 10 wt.% of the enzyme could be quantitatively bound to supports with retention of high levels of catalytic function, e.g., 68% specific activity at 4 wt.%. The non-reactive content of the polymeric support and especially the hydrophilic–hydrophobic balance were shown to be very important, with the hydrophilic supports providing the more favorable environment for hydrolytic esterase activity.