Tuning thermoresponsive supramolecular G-quadruplexes.
Tuning thermoresponsive supramolecular G-quadruplexes.
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DOI：
10.1021/la504446k
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发表时间：
2015-02-24
期刊：
影响因子：
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通讯作者：
Rivera JM
中科院分区：
文献类型：
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作者：
Betancourt JE;Rivera JM
温度响应系统是有吸引力的，因为它们适合于基础研究以及它们在各种各样的应用中的实际用途。虽然已经取得了很大的进展，使用聚合物，替代战略，如使用明确的非聚合物超分子仍然不发达。本文报道了三种8-芳基-2 ′-脱氧鸟苷衍生物（8Args）在水溶液中自组装成精确的温度响应性超分子G-四链体（SGQs）。我们报告的合成这样的衍生物，研究他们的等温自组装，和热诱导组装，形成更高阶的介观球状组件，我们术语超分子hacky袋（SHS）。通过改变（a）固有参数（即，8个Arg的结构）;（B）外在参数，例如用于促进SGQ形成的盐;和（c）超分子参数，例如共组装不同的8-Arg以形成异聚SGQ。内参数的变化导致LCST在28-59 °C范围内变化。调节外部参数，如用KSCN代替KI，消除了温度响应现象，而将阳离子从K+改变为Na+或调节pH（在6-8的范围内）对LCST的影响可以忽略不计。调制超分子参数的结果是在过渡温度之间的那些由各自的同聚SGQs获得的中间，虽然亚基的具体比例是决定过程的可逆性的关键。鉴于温敏聚合物的广泛应用，本文提出的非聚合物超分子对应物可能是基础研究和生物相关应用的一个有吸引力的选择。
Thermoresponsive systems are attractive due to their suitability for fundamental studies as well as their practical uses in a wide variety of applications. While much progress has been achieved using polymers, alternative strategies such as the use of well-defined nonpolymeric supramolecules are still underdeveloped. Here we report three 8-aryl-2′-deoxyguanosine derivatives (8ArGs) that self-assemble in aqueous media into precise thermoresponsive supramolecular G-quadruplexes (SGQs). We report the synthesis of such derivatives, studies of their isothermal self-assembly, and the thermally induced assembly to form higher-order meso-globular assemblies we term supramolecular hacky sacks (SHS). The lower critical solution temperature (LCST) that indicates the formation of the SHS was modulated by changing (a) intrinsic parameters (i.e., structure of the 8ArGs); (b) extrinsic parameters such as the salt used to promote the formation of the SGQ; and (c) supramolecular parameters such as the coassembly different 8ArGs to form heteromeric SGQs. Changes in the intrinsic parameters lead to LCST variations in the range of 28–59 °C. Modulating extrinsic parameters such as replacing KI with KSCN abolishes the thermoresponsive phenomenon whereas changing the cation from K+ to Na+ or adjusting the pH (in the range of 6–8) has negligible effects on the LCST. Modulating supramolecular parameters results in transition temperatures that are intermediate between those obtained by the respective homomeric SGQs, although the specific proportions of the subunits are critical in determining the reversibility of the process. Given the extensive applications of thermoresponsive polymers, the nonpolymeric supramolecular counterparts presented here may represent an attractive alternative for fundamental studies and biorelevant applications.