title: Immobilized Escherichia coli BL21 as a catalyst for the synthesis of adenine and hypoxanthine nucleosides.
abstract: Different supports, such as alginate, agar, agarose, and polyacrylamide, were used to immobilize Escherichia coli BL 21 by entrapment techniques. The transglycosylation reaction involved in the synthesis of adenosine from uridine and adenine was chosen as a model system to study the characteristics of these biocatalysts. Whole cells immobilized on agarose proved to be optimal and could be used up to 30 times without significant loss of activity. This biocatalyst was further employed to test its ability in the synthesis of other adenine and hypoxanthine nucleosides. Ribo-, 2'-deoxyribo-, and arabinonucleosides could be prepared in high yields starting from the corresponding pyrimidine nucleosides and purine bases. Similar product yields were obtained with both free and immobilized cells, though, in the latter case, a longer reaction time was necessary.
authors.affiliation: Universidad Nacional de Quilmes. R.S. Peña 180, (1876) Bernal, Buenos Aires, Argentina.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Trelles
authors.forename: Leticia
authors.initials: L
authors.lastname: Bentancor
authors.forename: Alejandra
authors.initials: A
authors.lastname: Schoijet
authors.forename: Silvia
authors.initials: S
authors.lastname: Porro
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Lewkowicz
authors.forename: José V
authors.initials: JV
authors.lastname: Sinisterra
authors.forename: Adolfo M
authors.initials: AM
authors.lastname: Iribarren
mesh_terms: D000225:Adenine / Q000096:biosynthesis* / Q000737:chemistry; D002384:Catalysis; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000737:chemistry; D019271:Hypoxanthine / Q000737:chemistry / Q000378:metabolism*; D009705:Nucleosides / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D029968:Escherichia coli Proteins; D009705:Nucleosides; D019271:Hypoxanthine; D000225:Adenine