Atomic Structure of a Fluorescent Ag8 Cluster Templated by a Multistranded DNA Scaffold
Atomic Structure of a Fluorescent Ag8 Cluster Templated by a Multistranded DNA Scaffold
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DOI：
10.1021/jacs.8b12203
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发表时间：
2019-07-24
影响因子：
15
通讯作者：
Lieberman, Raquel L.
中科院分区：
文献类型：
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作者：
Huard, Dustin J. E.;Demissie, Aida;Lieberman, Raquel L.
DNA 封装的多核银簇表现出尺寸可调的发射光谱和丰富的光物理学，但人们对它们的原子组织知之甚少。在此，我们描述了一种这样的杂合发色团的结构，一种发绿光的银簇，排列成北斗七星形状，与寡核苷酸 A(2)C(4) 结合。三个 3' 胞嘧啶金属碱基对稳定具有富含 S' 腺嘌呤口袋的平行 A 型双链体，该双链体通过 Ag-N 键与胞嘧啶和腺嘌呤的内环和外环氮结合金属梯形 Ag-5 部分。独特的DNA构型、受限的配位环境和模板化的Ag-8簇排列突出了银和DNA在采用这种结构时的相互作用。 DNA 封装的银簇荧光团的这些第一批原子细节阐明了生物组装、纳米科学和金属簇光物理学的许多方面。
Multinuclear silver clusters encapsulated by DNA exhibit size-tunable emission spectra and rich photophysics, but their atomic organization is poorly understood. Herein, we describe the structure of one such hybrid chromophore, a green-emitting Ag, cluster arranged in a Big Dipper-shape bound to the oligonucleotide A(2)C(4). Three 3' cytosine metallo-base pairs stabilize a parallel A form-like duplex with a S' adenine-rich pocket, which binds a metallic, trapezoidal-shaped Ag-5 moiety via Ag-N bonds to endo- and exocyclic nitrogens of cytosine and adenine. The unique DNA configuration, constrained coordination environment, and templated Ag-8 cluster arrangement highlight the reciprocity between the silvers and DNA in adopting this structure. These first atomic details of a DNA-encapsulated Ag cluster fluorophore illuminate many aspects of biological assembly, nanoscience, and metal cluster photophysics.