Department of Chemistry, University of Wyoming, 1000 E. University ave., Laramie, WY 82071, USA.
Org Biomol Chem. 2012 Aug 7;10(29):5533-40. doi: 10.1039/c2ob25710f. Epub 2012 Jun 12.
DNA has found widespread uses as a nanosized scaffold for assembly of patterned multichomophoric nanostructures. Herein we report the synthesis, self-assembly, stability, and spectroscopic studies of short alternating non-self-complementary DNA sequences 5'-(dGdA)(4) and 5'-(dAdG)(4) with non-charged tetraarylporphyrins covalently linked to the 5' position of deoxyadenosine or deoxyguanosine via a phosphate or amide linker. The linker, the metal in the porphyrin coordination center, and the neighboring nucleobase have very distinct effects on the duplex formation of porphyrin-deoxyguanosine-deoxyadenosine oligodeoxynucleotides. At ionic strength between 5 mM and 40 mM, free base trispyridylphenylporphyrin appended to the 5' termini of 5'-(dAdG)(4) oligonucleotide via short non-polar amide linker served as a hydrophobic molecular cap inducing deoxyadenosine-deoxyguanosine antiparallel homoduplex. At ionic strength of ≥60 mM, the free base porphyrin functioned as a molecular 'glue' and induced the formation of porphyrin-DNA inter-homoduplex assemblies with characteristic tetrasignate CD Cotton effects in the porphyrin Soret band region. When the porphyrin cap was covalently attached to 5' position of deoxyguanosine or deoxyadenosine via charged phosphate linker, no significant deoxyadenosine-deoxyguanosine hybridization was observed even at elevated ionic strengths.
DNA 已被广泛用作组装图案化多联体纳米结构的纳米级支架。在此，我们报告了短交替非自互补 DNA 序列 5'-(dGdA)(4)和 5'-(dAdG)(4)的合成、自组装、稳定性和光谱研究，这些序列通过磷酸酯或酰胺键与 5' 位的脱氧腺苷或脱氧鸟苷共价连接，带有非电荷的四芳基卟啉。连接体、卟啉配位中心的金属以及相邻的碱基对脱氧鸟苷-脱氧腺苷寡脱氧核苷酸的双链形成有非常明显的影响。在离子强度为 5 mM 至 40 mM 之间时，通过短非极性酰胺键连接到 5'-(dAdG)(4)寡核苷酸 5' 末端的游离碱基三吡啶基苯基卟啉作为疏水分子帽，诱导脱氧腺苷-脱氧鸟苷反平行同源双链体的形成。在离子强度≥60 mM 时，游离碱基卟啉作为分子“胶”，诱导形成具有特征四标志 CD 圆二色性 Cotton 效应的卟啉-DNA 内同源二聚体组装体在卟啉 Soret 带区域。当卟啉帽通过带电荷的磷酸酯键连接到脱氧鸟苷或脱氧腺苷的 5' 位时，即使在升高的离子强度下，也观察不到明显的脱氧腺苷-脱氧鸟苷杂交。
