title: Immobilized uroporphyrinogen I synthetase from Rhodopseudomonas palustris.
abstract: Rhodopseudomonas palustris uroporphyrinogen I synthetase (URO-S) has been chemically attached to Sepharose 4B and some of its properties have been studied. When 7-8 mg protein/ml activated Sepharose was used, immobilized URO-S retained 45% of the activity of the original soluble preparation, with a coupling yield of 66% after a period of 15 h. Optimal incubation conditions for the activity of gel-enzyme were determined. Unlike the soluble enzyme, the Sepharose-bound URO-S showed a biphasic substrate saturation curve, indicating that a protein conformational change had occurred during the process of immobilization. Immobilized URO-S stored at 4 degrees C for 35 days retained 90% of activity and when repeatedly used, up to 5 times, retained 48% of the original activity. Attachment of URO-S to Sepharose led to an enhanced thermal stability.
authors.affiliation: Centro de Investigaciones sobre Porfirinas y Porfirias, Ciudad Universitaria, Buenos Aires, Argentina.
authors.forename: M L
authors.initials: ML
authors.lastname: Kotler
authors.forename: A A
authors.initials: AA
authors.lastname: Juknat
authors.forename: A M
authors.initials: AM
authors.lastname: Batlle
mesh_terms: D000642:Ammonia-Lyases / Q000378:metabolism*; D001709:Biotechnology; D004800:Enzymes, Immobilized; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D011163:Hydroxymethylbilane Synthase / Q000378:metabolism*; D007700:Kinetics; D012241:Rhodopseudomonas / Q000201:enzymology*; D012685:Sepharose
chemical_list: D004800:Enzymes, Immobilized; D012685:Sepharose; D011163:Hydroxymethylbilane Synthase; D000642:Ammonia-Lyases