title: Detoxification of ammonia by immobilized urea cycle enzymes.
abstract: Detoxication of ammonia was performed by dialysis of ammonia through a hollow fiber unit and by conversion to urea in a column reactor packed with immobilized urea cycle enzymes. Enzymes in the urea cycle could be immobilized by covalently binding on CNBr-activated Sepharose 4B. Ammonia was sequentially converted to urea by immobilized urea cycle enzymes with an ATP-regenerating system. Optimum conditions for the cyclic reaction were obtained theoretically and experimentally for performing continuous urea synthesis in a packed column reactor. Detoxication of ammonia of similar concentration to that in the blood in hepatic insufficiency was analyzed and performed experimentally in an extracorporeal model.
mesh_terms: D000255:Adenosine Triphosphate; D000641:Ammonia / Q000378:metabolism*; D001124:Argininosuccinate Synthase / Q000494:pharmacology; D001692:Biological Transport; D002222:Carbamoyl-Phosphate Synthase (Ammonia) / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000494:pharmacology*; D008658:Inactivation, Metabolic; D014508:Urea / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D000641:Ammonia; D000255:Adenosine Triphosphate; D014508:Urea; D002222:Carbamoyl-Phosphate Synthase (Ammonia); D001124:Argininosuccinate Synthase