title: Simple and efficient method to purify DNA-protein conjugates and its sensing applications.
abstract: DNA-protein conjugates are very useful in analytical chemistry for target recognition and signal amplification. While a number of methods for conjugating DNA with proteins are known, methods for purification of DNA-protein conjugates from reaction mixture containing unreacted proteins are much less investigated. In this work, a simple and efficient approach to purify DNA-invertase conjugates from reaction mixture via a biotin displacement strategy to release desthiobiotinylated DNA-invertase conjugates from streptavidin-coated magnetic beads was developed. The conjugates purified by this approach were utilized for quantitative detection of cocaine and DNA using a personal glucose meter through structure-switching DNA aptamer sensors and competitive DNA hybridization assays, respectively. In both cases, the purified DNA-invertase conjugates showed better performance compared to the same assays using unpurified conjugates. The approach demonstrated here can be further expanded to other DNA and proteins to generate purified DNA-protein conjugates for analytical and other applications.
authors.affiliation: Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University , Beijing 100084, China.
authors.forename: Zhaojuan
authors.initials: Z
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiang
authors.forename: Aijun
authors.initials: A
authors.lastname: Tong
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis; D001710:Biotin / Q000737:chemistry; D019921:Biotinylation; D003042:Cocaine / Q000032:analysis; D004247:DNA / Q000302:isolation & purification*; D005947:Glucose / Q000032:analysis; D011506:Proteins / Q000302:isolation & purification*; D019809:Streptavidin / Q000737:chemistry; D043324:beta-Fructofuranosidase / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D011506:Proteins; D001710:Biotin; D004247:DNA; D019809:Streptavidin; D043324:beta-Fructofuranosidase; D003042:Cocaine; D005947:Glucose