title: Phenylalanine ammonia-lyase immobilized in semipermeable microcapsules for enzyme replacement in phenylketonuria.
abstract: Phenylalanine ammonia-lyase immobilized within semipermeable microcapsules has an assayed enzyme activity which is 20% +/- 4% of the enzyme in free solution. The Km for the immobilized enzyme remained the same as that of the free enzyme. The pH optimum also remained unchanged at pH 8.5 +/- 1.0. At the lower pH range, enzyme activity is higher for the immobilized enzyme. Daily oral administration of microencapsulated phenylalanine ammonia-lyase to phenylketonuric rats decreased the systemic phenylalanine level by 35 +/- 8% in 2 days (P less than 0.05) and by 75 +/- 8% in 7 days (P less than 0.001).
mesh_terms: D000642:Ammonia-Lyases / Q000627:therapeutic use*; D000818:Animals; D002214:Capsules; D004800:Enzymes, Immobilized / Q000627:therapeutic use*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D010539:Permeability; D010650:Phenylalanine Ammonia-Lyase / Q000627:therapeutic use*; D010661:Phenylketonurias / Q000188:drug therapy*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002214:Capsules; D004800:Enzymes, Immobilized; D000642:Ammonia-Lyases; D010650:Phenylalanine Ammonia-Lyase