Sequence-dependent stability of DNA-modified gold nanoparticles
Sequence-dependent stability of DNA-modified gold nanoparticles
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DOI：
10.1021/la0202428
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发表时间：
2002-08-20
期刊：
影响因子：
3.9
通讯作者：
Letsinger, RL
中科院分区：
文献类型：
--
作者：
Storhofff, JJ;Elghanian, R;Letsinger, RL
使用比色测定法研究脱氧核苷（dA、dG、dC和dT）与金纳米颗粒的结合亲和力，以确定核碱基序列是否在将烷硫醇封端的寡核苷酸与金纳米颗粒结合中起作用。这些数据表明脱氧核苷dT与金纳米颗粒表面的结合亲和力比脱氧核苷dG、dC和dA低得多。这些数据可以与我们实验室先前的研究相关，该研究表明含有（dT）（20）间隔区的烷硫醇封端的寡核苷酸比含有（dA）（20）间隔区的寡核苷酸具有显著更高的表面覆盖率。为了探测这种现象的物理后果，金纳米粒子负载有链烷硫醇封端的聚dT，dA，和dC寡核苷酸序列的长度为5-20个碱基，和电解介质中的颗粒的稳定性进行测量，通过监测与颗粒团聚的比色变化。随着寡核苷酸长度从5个碱基增加到20个碱基，负载有烷硫醇封端的聚dT寡核苷酸的金纳米颗粒表现出稳定性的显著增加。通过比较，随着寡核苷酸长度的增加，装载有聚dC和聚dA序列的金纳米颗粒仅表现出稳定性的轻微增加。DNA修饰的金纳米颗粒观察到的序列依赖性稳定性归因于脱氧核苷dT与金纳米颗粒表面的较弱相互作用，这导致较高的表面覆盖率，并因此随着寡核苷酸长度的增加而增强稳定性。
The binding affinity of deoxynucleosides (dA, dG, dC, and dT) to gold nanoparticles was studied using a colorimetric assay to determine if nucleobase sequence may play a role in binding alkanethiol-capped oligonucleotides to gold nanoparticles. These data indicate that the deoxynucleoside dT has a much lower binding affinity to the gold nanoparticle surface than the deoxynucleosides dG, dC, and dA. These data can be correlated with a previous study in our lab which indicated that alkanethiol-capped oligonucleotides containing (dT)(20) spacers have a significantly higher surface coverage than oligonucleotides containing (dA)(20) spacers. To probe the physical consequences of this phenomenon, gold nanoparticles were loaded with alkanethiol-capped poly dT, dA, and dC oligonucleotide sequences of 5-20 bases in length, and the stabilities of the particles in electrolytic media were measured by monitoring a colorimetric change associated with particle agglomeration. The gold nanoparticles loaded with alkanethiol-capped poly dT oligonucleotides exhibited a dramatic increase in stability as the oligonucleotide length was increased from 5 to 20 bases. By comparison, gold nanoparticles loaded with poly dC and poly dA sequences exhibited only a slight increase in stability as the oligonucleotide length was increased. The sequence-dependent stability observed for the DNA-modified gold nanoparticles is attributed to the weaker interaction of the deoxynucleoside dT with the gold nanoparticle surface which results in higher surface coverages and consequently enhanced stability as the oligonucleotide length is increased.