TY - JOUR A1 - Fresco-Taboada, Alba AU - Serra, Immacolata AU - Fernández Lucas, Jesús AU - Acebal Sarabia, Carmen AU - Arroyo Sánchez, Miguel AU - Terreni, Marco AU - Mata Riesco, Isabel de la T1 - Nucleoside 2'-Deoxyribosyltransferase from psychrophilic bacterium bacillus psychrosaccharolyticus - Preparation of an immobilized biocatalyst for the enzymatic synthesis of therapeutic nucleosides Y1 - 2014 SN - 14203049 UR - http://hdl.handle.net/11268/3925 AB - Nucleoside 2'-deoxyribosyltransferase (NDT) from the psychrophilic bacterium Bacillus psychrosaccharolyticus CECT 4074 has been cloned and produced for the first time. A preliminary characterization of the recombinant protein indicates that the enzyme is an NDT type II since it catalyzes the transfer of 2'-deoxyribose between purines and pyrimidines. The enzyme (BpNDT) displays a high activity and stability in a broad range of pH and temperature. In addition, different approaches for the immobilization of BpNDT onto several supports have been studied in order to prepare a suitable biocatalyst for the one-step industrial enzymatic synthesis of different therapeutic nucleosides. Best results were obtained by adsorbing the enzyme on PEI-functionalized agarose and subsequent cross-linking with aldehyde-dextran (20 kDa and 70% oxidation degree). The immobilized enzyme could be recycled for at least 30 consecutive cycles in the synthesis of 2'-deoxyadenosine from 2'-deoxyuridine and adenine at 37 °C and pH 8.0, with a 25% loss of activity. High conversion yield of trifluridine (64.4%) was achieved in 2 h when 20 mM of 2'-deoxyuridine and 10 mM 5-trifluorothymine were employed in the transglycosylation reaction catalyzed by immobilized BpNDT at 37 °C and pH 7.5. KW - Biotecnología KW - Biotecnología LA - eng ER -