【作者】 朱丹； 赵东霞； 晁洁； 苏邵； 左小磊； 樊春海；

【Author】 Dan Zhu;Dongxia Zhao;Jie Chao;Shao Su;Xiaolei Zuo;Chunhai Fan;Institute of Advanced Materials (IAM) and School of Materials Science and Engineering, Nanjing University of Posts & Telecommunications;Division of Physical Biology & Bioimaging Center, Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences;

【机构】 南京邮电大学信息材料与纳米技术研究院/材料科学与工程学院； 中国科学院上海应用物理研究所物理生物学实验室；

【摘要】 酶复合体通常在二维脂质膜表面或在三维结构的蛋白上进行特定的空间排布调节其在细胞内的催化活性。受此启发,我们发展了一种活性可调控的DNA酶-纳米金（AuNPs）酶复合体（SNAzyme）,利用腺嘌呤与金之间的吸附作用^[1]将富含腺嘌呤（polyA）的DNA酶组装在纳米金表面。在此纳米酶复合体中,AuNPs和DNA酶分别作为金属核和具有功能性的壳结构。传统的DNA-AuNPs自组装通过巯基修饰的DNA与金之间的金-硫键作用完成,由于DNA在AuNPs表面组装的无序性,DNA酶的活性是受到抑制的。在此研究中,我们发现通过polyA修饰的DNA酶在AuNPs表面的活性可以得到有效调节。例如,端部含有polyA 30的SNAzyme与巯基修饰的SNAzyme相比,DNA酶的活性提高了约75倍,与溶液中游离的DNA酶相比活性提高了约10倍。此外,该纳米酶复合体应用于生物传感时表现出良好的亲和力和灵敏性,这为构建基于纳米酶复合体的高活性传感平台和生物成像探针提供了具有重要参考意义的研究基础。更多还原

【Abstract】 Enzyme complexes are assembled at the two-dimensional lipid membrane or prearranged on three-dimensional scaffolding proteins to regulate their catalytic activity in cells.Inspired by nature,we have developed gold nanoparticle-based spherical DNAzymes(SNAzymes) with programmably engineered activities by exploiting poly-adenine(polyA)-Au interactions.In a SNAzyme,AuNPs serve as the metal core,which is decorated with a functional shell of DNAzymes.Conventional thiolated DNAzyme-based assembly leads to disordered structures with suppressed activity.In contrast,by using an anchoring block of polyA tails,we find that the activity of SNAzymes can be programmably regulated.By using a polyA30 tail,SNAzymes demonstrated remarkably enhanced binding affinity compared to the thiolated DNAzyme-based assembly(~75-fold) or individual DNAzymes in the solution phase(~ 10-fold).More significantly,this increased affinity is directly translated to the sensitivity improvement in the SNAzyme-based lead sensor.Hence,this design of SNAzymes may provide new opportunities for developing biosensors and bioimaging probes for theranostic applications.更多还原