Kaluzhny Dmitry, Shchyolkina Anna, Livshits Michael, Lysov Yury, Borisova Olga
Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, Moscow, Russia.
Biophys Chem. 2009 Aug;143(3):161-5. doi: 10.1016/j.bpc.2009.05.006. Epub 2009 May 20.
Human genome is shown to be enriched with (GT)(n) stretches of lengths from 8 to 20 dinucleotides. Low temperature (T< or =10 degrees C) conformations of d(GT)(n) oligonucleotides (n=7, 8, 12, 16, 20) were studied by means of circular dichroism (CD), thermal melting, ethidium bromide (EtBr) probing and single nucleotide substitutions. Rotational relaxation times for EtBr:d(GT)(n) complexes confirmed a monomolecular state of the oligonucleotides. CD spectra indicated involvement of all guanines of d(GT)(8) and d(GT)(16) in G-quartets, while dT(GT)(7), d(GT)(12) and d(GT)(20) were shown to be only partially ordered. The schemes of the d(GT)(8) and d(GT)(16) folds are suggested.
研究表明，人类基因组富含长度为8至20个二核苷酸的(GT)(n)片段。通过圆二色性（CD）、热变性、溴化乙锭（EtBr）探针法和单核苷酸替换，研究了d(GT)(n)寡核苷酸（n = 7、8、12、16、20）在低温（T≤10℃）下的构象。EtBr:d(GT)(n)复合物的旋转弛豫时间证实了寡核苷酸的单分子状态。CD光谱表明，d(GT)(8)和d(GT)(16)的所有鸟嘌呤都参与了G-四联体的形成，而dT(GT)(7)、d(GT)(12)和d(GT)(20)仅部分有序。文中提出了d(GT)(8)和d(GT)(16)的折叠方案。
