Petty Tyler J, Wagner Caleb E, Opdahl Aric
Department of Chemistry and Biochemistry, University of Wisconsin-La Crosse , La Crosse, Wisconsin 54601, United States.
Langmuir. 2014 Dec 23;30(50):15277-84. doi: 10.1021/la504128h. Epub 2014 Dec 12.
The thermal stabilities of double-stranded DNA hybrids immobilized on gold surfaces are shown to be significantly affected by the conformation of the hybrid. To analyze this behavior, DNA probes were immobilized using attachment strategies where the nucleotides within the strand had varying levels of interactions with the gold substrate. The abilities of these probes to form double-stranded hybrids with solution DNA targets were evaluated by surface plasmon resonance (SPR) over a temperature range 25-60 °C. The measurements were used to construct thermal stability profiles for hybrids in each conformation. We observe that DNA hybrids formed with probe strands that interact extensively with the gold surface have stability profiles that are shifted lower by 5-10 °C compared to hybrids formed with end-tethered probes that have fewer interactions with the surface. The results provide an understanding of the experimental conditions in which these weaker DNA hybrids can form and show the additional complexity of evaluating denaturation profiles generated from DNA on surfaces.
固定在金表面的双链DNA杂交体的热稳定性受杂交体构象的显著影响。为了分析这种行为，使用连接策略固定DNA探针，其中链内的核苷酸与金底物具有不同程度的相互作用。通过表面等离子体共振（SPR）在25-60°C的温度范围内评估这些探针与溶液DNA靶标形成双链杂交体的能力。这些测量用于构建每种构象中杂交体的热稳定性曲线。我们观察到，与与表面相互作用较少的末端连接探针形成的杂交体相比，与金表面广泛相互作用的探针链形成的DNA杂交体的稳定性曲线向下偏移5-10°C。结果有助于理解这些较弱DNA杂交体能够形成的实验条件，并显示了评估表面DNA产生的变性曲线的额外复杂性。
