title: Selection of DNA aptamers against insulin and construction of an aptameric enzyme subunit for insulin sensing.
abstract: We selected DNA aptamers against insulin and developed an aptameric enzyme subunit (AES) for insulin sensing. The insulin-binding aptamers were identified from a single-strand DNA library which was expected to form various kinds of G-quartet structures. In vitro selection was carried out by means of aptamer blotting, which visualizes the oligonucleotides binding to the target protein at each round. After the 6th round of selection, insulin-binding aptamers were identified. These identified insulin-binding aptamers had a higher binding ability than the insulin-linked polymorphic region (ILPR) oligonucleotide, which can be called a "natural" insulin-binding DNA aptamer. The circular-dichroism (CD) spectrum measurement of the identified insulin-binding DNA aptamers indicated that the aptamers would fold into a G-quartet structure. We also developed an AES by connecting the best identified insulin-binding aptamer with the thrombin-inhibiting aptamer. Using this AES, we were able to detect insulin by measuring the thrombin enzymatic activity without bound/free separation.
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Yoshida
authors.forename: Eriko
authors.initials: E
authors.lastname: Mochizuki
authors.forename: Madoka
authors.initials: M
authors.lastname: Takase
authors.forename: Hijiri
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Yo
authors.initials: Y
authors.lastname: Morita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Koji
authors.initials: K
authors.lastname: Sode
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ikebukuro
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007328:Insulin / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D007328:Insulin