title: Rational design of modular allosteric aptamer sensor for label-free protein detection.
abstract: An aptamer can be redesigned to new functional molecules by conjugating with other oligonucleotides. However, it requires experimental trials to optimize the conjugating module with the sensitivity and selectivity toward a target. To reduce these efforts, we report rationally-designed modular allosteric aptamer sensor (MAAS), which is composed of coupled two aptamers and the regulator. For label-free protein detection, the protein-aptamer was conjugated with the malachite green (MG) aptamer for signaling. The MAAS additionally has the regulator domain which is designed to hybridize to a protein binding domain. The regulator makes MAAS to be inactive by destructing the original structure of the two aptamers. However, its conformation becomes active by dissociating the hybridization from the protein recognition signal, thereby inducing the binding of MG emitting the enhanced fluorescence. The design of regulator is based on the thermodynamic energy difference by the RNA conformational change and protein-aptamer affinity. Here we first demonstrated the MAAS for hepatitis C helicase and replicase. The target proteins were detected up to 250nM with minimized blank signals and displayed high specificities 10-fold greater than in non-specific proteins. The MAAS provides valuable tools that can be adapted to a wide range of configurations in bioanalytical applications.
authors: Nano Materials Laboratory, National NanoFab Center, Gwahangno, Yuseong-gu, Daejeon 305 806, Korea.
authors: Gyeong Sook
authors: GS
authors: Bang
authors: Suhyung
authors: S
authors: Cho
authors: Nahum
authors: N
authors: Lee
authors: Bo-Rahm
authors: BR
authors: Lee
authors: June-Hyung
authors: JH
authors: Kim
authors: Byung-Gee
authors: BG
authors: Kim
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D016174:Hepacivirus / Q000201:enzymology*; D006526:Hepatitis C / Q000821:virology; D006801:Humans; D009690:Nucleic Acid Conformation; D020365:RNA Helicases / Q000032:analysis*; D012324:RNA-Dependent RNA Polymerase / Q000032:analysis*; D012394:Rosaniline Dyes / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D052157:Aptamers, Nucleotide; D012394:Rosaniline Dyes; C005095:malachite green; D012324:RNA-Dependent RNA Polymerase; D020365:RNA Helicases