Stepp Brian R, Gibbs-Davis Julianne M, Koh Dorothea L F, Nguyen SonBinh T
Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA.
J Am Chem Soc. 2008 Jul 30;130(30):9628-9. doi: 10.1021/ja801572n. Epub 2008 Jul 3.
Rigid small-molecule DNA hybrids (rSMDHs) have been synthesized with three DNA strands attached to a rigid tris(phenylacetylene) core. When combined under dilute conditions, complementary rSMDHs form cage dimers that melt at >10 degrees C higher and much sharper than either unmodified DNA duplexes or rSMDH aggregates formed at higher concentrations. With a 2.97 average number of cooperative duplexes, these caged dimers constitute the first example of cooperative melting in well-defined DNA-small-molecule structures, demonstrating the important roles that local geometry and ion concentration play in the hybridization/dehybridization of DNA-based materials.
刚性小分子DNA杂合体（rSMDHs）已通过将三条DNA链连接到刚性三（苯乙炔）核心上合成而成。在稀释条件下混合时，互补的rSMDHs形成笼状二聚体，其熔点比未修饰的DNA双链体或在较高浓度下形成的rSMDH聚集体高10摄氏度以上，且熔解峰更尖锐。这些笼状二聚体平均具有2.97个协同双链体，构成了明确的DNA-小分子结构中协同熔解的首个实例，证明了局部几何形状和离子浓度在基于DNA的材料杂交/解杂交过程中所起的重要作用。
