Li Li, Pabit Suzette A, Lamb Jessica S, Park Hye Yoon, Pollack Lois
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Appl Phys Lett. 2008 Jun 2;92(22):223901-2239013. doi: 10.1063/1.2937402.
Recent experiments suggest that short DNA strands associate by end-to-end stacking. Here, we report interactions between DNAs with modified ends. DNA duplexes, 20 bp long, were capped with short T(4) loops at 2, 1 or 0 ends, and were placed in solutions containing 20 mM Mg(2+). Association was observed only in constructs with one or more uncapped ends. DNA-DNA interactions were characterized by measuring variations in small angle x-ray scattering (SAXS) curves at the lowest scattering angles. Second virial coefficients were computed from the SAXS data. Our results confirm that end-to-end stacking plays an important role in short strand DNA-DNA interactions.
近期实验表明，短DNA链通过端对端堆积相互结合。在此，我们报告了具有修饰末端的DNA之间的相互作用。20个碱基对长的DNA双链体在2个、1个或0个末端被短T(4)环封闭，并置于含有20 mM Mg(2+)的溶液中。仅在具有一个或多个未封闭末端的构建体中观察到结合。通过测量最低散射角处小角X射线散射（SAXS）曲线的变化来表征DNA-DNA相互作用。从SAXS数据计算第二维里系数。我们的结果证实，端对端堆积在短链DNA-DNA相互作用中起重要作用。
