TY - JOUR 
A1 - Fernández Lucas, Jesús
AU - Harris, Ruth
AU - Mata Casar, Iría
AU - Heras, Ángeles
AU - Arroyo Sánchez, Miguel
T1 - Magnetic chitosan beads for covalent immobilization of nucleoside 2'-deoxyribosyltransferase: application in nucleoside analogues synthesis
Y1 - 2013
SN - 14765535
UR - http://hdl.handle.net/11268/716
AB - Cross-linked magnetic chitosan beads were prepared in presence of epichlorohydrin under alkaline conditions, and subsequently incubated with glutaraldehyde in order to obtain an activated support for covalent attachment of nucleoside 2'-deoxyribosyltransferase from Lactobacillus reuteri (LrNDT). Changing the amount of magnetite (Fe3O4) and epichlorohydrin (EPI) led to different macroscopic beads to be used as supports for enzyme immobilization, whose morphology and properties were characterized by scanning electron microscopy, spin electron resonance (ESR), and vibrating sample magnetometry (VSM). Once activated with glutaraldehyde, the best support was chosen after evaluation of immobilization yield and product yield in the synthesis of thymidine from 2'-deoxyuridine and thymine. In addition, optimal conditions for highest activity of immobilized LrNDT on magnetic chitosan were determined by response surface methodology (RSM). Immobilized biocatalyst retained 50 % of its maximal activity after 56.3 h at 60 °C, whereas 100 % activity was observed after storage at 40 °C for 144 h. This novel immobilized biocatalyst has been successfully employed in the enzymatic synthesis of 2'-deoxyribonucleoside analogues as well as arabinosyl-nucleosides such as vidarabine (ara-A) and cytarabine (ara-C). Furthermore, this is the first report which describes the enzymatic synthesis of these arabinosyl-nucleosides catalyzed by an immobilized nucleoside 2'-deoxyribosyltransferase. Finally, the attached enzyme to magnetic chitosan beads could be easily recovered and recycled for 30 consecutive batch reactions with negligible loss of catalytic activity in the synthesis of 2,6-diaminopurine-2'-deoxyriboside and 5-trifluorothymidine.;
KW - Genética humana
KW - Endocrinología
LA - eng
ER -