title: A new application of aptamer: One-step purification and immobilization of enzyme from cell lysates for biocatalysis.
abstract: Aptamers are nucleic acid-based high affinity ligands that are able to capture their corresponding target through molecular recognition. In this study, several DNA aptamers with high affinity and specificity for β-glucuronidases (PGUS-E) were obtained by our modified SELEX method. Among them, Apt5 and Apt9 were selected as representatives and covalently linked to magnetic beads, respectively. The aptamer-modified magnetic beads were characterized and successfully applied to one-step purification and immobilization of PGUS-E from the complex cell lysates. By conveniently adjusting the pH and ion strength, the PGUS-E purities reached 84% for Apt5-modified beads and 88% for Apt9-modified beads. Moreover, the maximum PGUS-E capturing capacity of the Apt5 and Apt9 modified magnetic beads were found to be 31.75μg/mg and 32.95μg/mg, respectively. The immobilized PGUS-E on aptamer-based magnetic beads showed good reusability, and the conversion of glycyrrhizin still remained more than 70% after 7 cycles. In addition, the aptamer-modified beads support can be easily regenerated, and the conversion rate of glycyrrhizin (GL) was still 62% after the 7th cycle of regeneration. This investigation can be easily extended to other enzyme systems and may help open a generic route to develop a novel enzyme immobilization technology for biocatalysis based on aptamer.
authors.affiliation: School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, Xinjiang, PR China.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Qiao
authors.affiliation: School of Life Science and Technology, Beijing Institute of Technology, Beijing, 100081, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Lv
authors.affiliation: School of Life Science and Technology, Beijing Institute of Technology, Beijing, 100081, PR China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Feng
authors.affiliation: School of Life Science and Technology, Beijing Institute of Technology, Beijing, 100081, PR China. Electronic address: lichun@bit.edu.cn.
authors.forename: Chun
authors.initials: C
authors.lastname: Li
mesh_terms: D052157:Aptamers, Nucleotide; D055162:Biocatalysis; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D005966:Glucuronidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D052156:SELEX Aptamer Technique
chemical_list: D052157:Aptamers, Nucleotide; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D005966:Glucuronidase
keywords: Aptamer; Biocatalysis; Immobilization; Purification; β-Glucuronidases