[Coordination-ionic enzyme immobilization. Dependence of properties of immobilized preparations of penicillinamidohydrolase on the nature of metal ion and stationary ligand].

Penicillinamidohydrolase was immobilized on heteroporous polystyrene supports containing groups of ethylenediamine, diethylenetriamine and triethylenetetramine, using Co(II), Ni(II), Cu(II), Fe(III), Co(III) ions. The effects of substrate concentrations and pH on the activity of the immobilized enzyme were investigated and the kinetic parameters of hydrolysis were determined, using N-phenacetylphenylglycine as substrate. The enzyme immobilization resulted in a slight decrease of Km(app), while the values of V decreased by a factor of two. Preparations possessing high thermal stability were obtained by oxidation of Co(II) to Co(III) in the enzyme sorption complex. High stability was also found for the Fe(III)-containing preparations.