Kobori Akio, Horie Souta, Suda Hitoshi, Saito Isao, Nakatani Kazuhiko
PRESTO, Japan Science and Technology Agency (JST), Kyoto 615-8510, Japan.
J Am Chem Soc. 2004 Jan 21;126(2):557-62. doi: 10.1021/ja037947w.
We have synthesized the first surface plasmon resonance (SPR) sensor that detects cytosine-cytosine (C[bond]C) mismatches in duplex DNA by immobilizing aminonaphthyridine dimer on the gold surface. The ligand consisting of two 2-aminonaphthyridine chromophores and an alkyl linker connecting them strongly stabilized the C[bond]C mismatches regardless of the flanking sequences. The fully matched duplexes were not stabilized at all under the same conditions. The C[bond]T, C[bond]A, and T[bond]T mismatches were also stabilized with a reduced efficiency. SPR analyses of mismatch-containing 27-mer duplexes were performed with the sensor surface on which the aminonaphthyridine dimer was immobilized. The response for the C[bond]C mismatch in 5'-GCC-3'/3'-CCG-5' was about 83 times stronger than that obtained for the fully matched duplex. The sensor successfully detects the C[bond]C mismatch at the concentration of 10 nM. SPR responses are proportional to the concentration of the C[bond]C mismatch in a range up to 200 nM. Aminonaphthyridine dimer could bind strongly to the C[bond]C mismatches having 10 possible flanking sequences with association constants in the order of 10(6) M(-1). The facile protonation of 2-aminonaphthyridine chromophore at pH 7 producing the hydrogen-bonding surface complementary to that of cytosine was most likely due to the remarkably high selectivity of 1 to the C[bond]C mismatch.
我们合成了首个表面等离子体共振（SPR）传感器，该传感器通过将氨基萘啶二聚体固定在金表面来检测双链DNA中的胞嘧啶-胞嘧啶（C≡C）错配。由两个2-氨基萘啶发色团和连接它们的烷基接头组成的配体，无论侧翼序列如何，都能强烈稳定C≡C错配。在相同条件下，完全匹配的双链体根本没有得到稳定。C≡T、C≡A和T≡T错配也能以较低的效率得到稳定。使用固定了氨基萘啶二聚体的传感器表面，对含有错配的27聚体双链体进行了SPR分析。5'-GCC-3'/3'-CCG-5'中C≡C错配的响应比完全匹配的双链体强约83倍。该传感器在10 nM的浓度下成功检测到C≡C错配。在高达200 nM的范围内，SPR响应与C≡C错配的浓度成正比。氨基萘啶二聚体可以与具有10种可能侧翼序列的C≡C错配紧密结合，缔合常数约为10(6) M(-1)。2-氨基萘啶发色团在pH 7时容易质子化，产生与胞嘧啶互补的氢键表面，这很可能是由于其对C≡C错配具有极高的选择性（1）。
