title: ssDNA aptamer-based surface plasmon resonance biosensor for the detection of retinol binding protein 4 for the early diagnosis of type 2 diabetes.
abstract: Retinol binding protein 4 (RBP4) is a useful biomarker in the diagnosis of type 2 diabetes since its level in the serum is higher in insulin-resistant states. Accurate measurement of the serum RBP4 levels is hampered by conventional immunologic methods, such as enzyme-linked immunosorbent assay (ELISA). In this study, therefore, we have developed an aptamer-based surface plasmon resonance (SPR) biosensor that can be used to sense for RBP4 in serum samples. A single-stranded DNA (ssDNA) aptamer that showed high affinity (Kd = 0.2 +/- 0.03 microM) and specificity to RBP4 was selected. This RBP4-specific aptamer was immobilized on a gold chip and used in a label-free RBP4 detection using SPR. Analysis of RBP4 in artificial serum using SPR was compared with ELISA and Western blot analysis. Our results indicated that the RBP4-specific aptamer-based SPR biosensor gave better dose-dependent responses and was more sensitive than ELISA assays. As such, this RBP4 aptamer-based SPR biosensor can be potentially used to monitor the RBP4 levels within the serum as an indicator of type 2 diabetes.
authors.affiliation: School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-701, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Byung-Soo
authors.initials: BS
authors.lastname: Youn
authors.forename: Ji Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Javed H
authors.initials: JH
authors.lastname: Niazi
authors.forename: Yeon Seok
authors.initials: YS
authors.lastname: Kim
authors.forename: Man Bock
authors.initials: MB
authors.lastname: Gu
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods; D015153:Blotting, Western; D002417:Cattle; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D054839:Retinol-Binding Proteins, Plasma / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma