Choi Jung Kyu, Reed Aisha, Balaz Milan
Department of Chemistry, University of Wyoming, Laramie, WY 82071, USA.
Dalton Trans. 2014 Jan 14;43(2):563-7. doi: 10.1039/c3dt52210e.
We have studied the UV-vis absorption and chiroptical properties, binding affinity and photostability of a conjugated positively charged butadiyne-linked Zn(ii) porphyrin dimer bound to DNA sequence poly(dG-dC)2. Right-handed B-DNA, spermine-induced Z-DNA and Co(iii)-induced Z-DNA have been explored. Resonance light scattering (RLS) spectra showed formation of porphyrin aggregates in the presence of all DNA forms with the largest aggregates formed with B-DNA. The porphyrin dimer gave rise to induced bisignate circular dichroism (CD) signals in the presence of the left-handed Z-DNA conformations. On the other hand, the dimer stayed nearly chiroptically silent when complexed with the B-form of poly(dG-dC)2. Our results indicated that the conjugated Zn(ii) porphyrin dimer can be used as a sensor for the chiroptical detection of Z-DNA in the visible (400-500 nm) and near-infrared region of the electromagnetic spectrum (700-800 nm). The helicity of DNA had little effect on the dimer binding affinities. The photostability of the porphyrin dimer complexed with any form of DNA was higher than that of the free molecule. The porphyrin dimer bound to Z-DNA exhibited slower photobleaching than the B-DNA dimer complex.
我们研究了与DNA序列聚（dG-dC）2结合的共轭带正电荷的丁二炔连接的锌（II）卟啉二聚体的紫外可见吸收和手性光学性质、结合亲和力和光稳定性。研究了右手B-DNA、精胺诱导的Z-DNA和钴（III）诱导的Z-DNA。共振光散射（RLS）光谱表明，在所有DNA形式存在下都会形成卟啉聚集体，其中与B-DNA形成的聚集体最大。在左手Z-DNA构象存在下，卟啉二聚体产生诱导的双信号圆二色性（CD）信号。另一方面，当与聚（dG-dC）2的B型复合时，二聚体在手性光学上几乎保持沉默。我们的结果表明，共轭锌（II）卟啉二聚体可作为一种传感器，用于在电磁光谱的可见光（400-500nm）和近红外区域（700-800nm）对手性Z-DNA进行检测。DNA的螺旋度对二聚体结合亲和力影响很小。与任何形式的DNA复合的卟啉二聚体的光稳定性高于游离分子。与Z-DNA结合的卟啉二聚体比与B-DNA二聚体复合物表现出更慢的光漂白。
