title: DNA-Directed Assembly of Nanogold Dimers: A Unique Dynamic Light Scattering Sensing Probe for Transcription Factor Detection.
abstract: We have developed a unique DNA-assembled gold nanoparticles (AuNPs) dimer for dynamic light scattering (DLS) sensing of transcription factors, exemplified by estrogen receptor (ER) that binds specifically to a double-stranded (ds) DNA sequence containing estrogen response element (ERE). Here, ERE sequence is incorporated into the DNA linkers to bridge the AuNPs dimer for ER binding. Coupled with DLS, this AuNP dimer-based DLS detection system gave distinct readout of a single 'complex peak' in the presence of the target molecule (i.e., ER). This unique signature marked the first time that such nanostructures can be used to study transcription factor-DNA interactions, which DLS alone cannot do. This was also unlike previously reported AuNP-DLS assays that gave random and broad distribution of particles size upon target binding. In addition, the ERE-containing AuNP dimers could also suppress the light-scattering signal from the unbound proteins and other interfering factors (e.g., buffer background), and has potential for sensitive detection of target proteins in complex biological samples such as cell lysates. In short, the as-developed AuNP dimer probe coupled with DLS is a simple (mix and test), rapid (readout in ~5 min) and sensitive (low nM levels of ER) platform to detect sequence-specific protein-DNA binding event.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Faculty of Engineering, National University of Singapore, Singapore 119260, Singapore.
authors.forename: Nianjia
authors.initials: N
authors.lastname: Seow
authors.affiliation: Institute of Material Research and Engineering, ASTAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602.
authors.forename: Yen Nee
authors.initials: YN
authors.lastname: Tan
authors.affiliation: Department of Chemical and Biomolecular Engineering, Faculty of Engineering, National University of Singapore, Singapore 119260, Singapore.
authors.forename: Lin-Yue Lanry
authors.initials: LY
authors.lastname: Yung
authors.affiliation: Institute of Material Research and Engineering, ASTAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602.
authors.forename: Xiaodi
authors.initials: X
authors.lastname: Su
mesh_terms: D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D000067493:Dynamic Light Scattering; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D020218:Response Elements / Q000235:genetics
chemical_list: D047629:Estrogen Receptor beta; D006046:Gold; D004247:DNA