Conversion of ammonia or urea into L-leucine, L-valine, and L-isoleucine using artificial cells containing an immobilized multienzyme system and dextran-NAD+. Glucose dehydrogenase for co-factor recycling.
Artificial cells containing glucose dehydrogenase (EC 1.1.1.47), leucine dehydrogenase (EC 1.4.1.9), urease (EC 3.5.1.5), and dextran-NAD+ were prepared. Ammonia or urea could be converted into L-leucine, L-valine, and L-isoleucine with artificial cells. Low-specific-activity glucose dehydrogenase could effectively regenerate dextran-NADH, which was recycled at a rate of 0.4 to 0.5 cycle per minute under reaction conditions. The effects of ammonium salts and urea on the conversion rate for the leucine dehydrogenase multienzyme system were also studied. The relative activities in ammonium salts solutions were 40 to 70% of those in urea solutions.
Gu
K F
KF
Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
Chang
T M
TM
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000601:Amino Acids, Essential / Q000378:metabolism*; D000641:Ammonia / Q000378:metabolism*; D002214:Capsules; D002237:Carbohydrate Dehydrogenases / Q000378:metabolism*; D003911:Dextrans / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D042843:Glucose 1-Dehydrogenase; D005948:Glucose Dehydrogenases / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D050803:Leucine Dehydrogenase; D009097:Multienzyme Complexes / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D014508:Urea / Q000378:metabolism*; D014510:Urease / Q000378:metabolism
D000601:Amino Acids, Essential; D002214:Capsules; D003911:Dextrans; D004800:Enzymes, Immobilized; D009097:Multienzyme Complexes; D009243:NAD; D000641:Ammonia; D014508:Urea; D002237:Carbohydrate Dehydrogenases; D005948:Glucose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; D000594:Amino Acid Oxidoreductases; D050803:Leucine Dehydrogenase; D014510:Urease