Regulation of ion recognition by utilizing information at the molecular level
Regulation of ion recognition by utilizing information at the molecular level
复制标题
DOI：
10.1016/0010-8545(95)01164-1
复制
发表时间：
1996-02-01
影响因子：
20.6
通讯作者：
Nabeshima, T
中科院分区：
文献类型：
--
作者：
Nabeshima, T
利用分子水平的信息调节分子功能对于阐明生物系统中的变构、协同、反馈等机制以及通过响应于这些信息的人工功能化分子调节生物分子系统是重要且必要的。特别地，分子功能之间的离子识别引起了很多关注，因为神经系统中的许多酶活性和刺激物的运输都是由离子结合控制的。因此，在这篇文章中，我们描述了利用重金属离子，电子，和一个小的有机分子作为外部效应器，第一个策略是生产假冠醚。使用重金属离子作为效应物。带有金属的线性聚醚的络合。在两个末端的结合位点产生相应的环状化合物（假冠醚）。该方法对控制碱金属识别是非常有效的。这一概念被应用到假穴醚和假硫代冠醚，这是一个很好的重金属离子的双重识别系统。此外，与重金属离子的络合用于调节分子识别。其次，硫醇和二硫化物之间的氧化还原反应被用于调节离子识别。结合位点的构象变化和/或空间排列的变化对于调节是有用的。然而，这些方法不足以构造完美的ah-or-none类型控件。通过在金属离子的结合位点中具有氧化还原门的冠醚成功地进行了理想的调节。门响应硫醇和二硫化物之间的氧化还原反应，以提供打开和关闭状态。开放状态为Ag（I）提供了显著选择性的结合位点。Ag（I）选择性被认为是由硫和氧原子的协同配位引起的。这是含硫冠醚高Ag（I）选择性的一般结合模式。调节离子识别的第三种策略是使用具有氢键位点的受体进行分子组装。该分子组装体对碱金属离子的一个新的结合位点是由多个聚醚链形成的，每个聚醚链对金属离子都不表现出结合能力。
The regulation of molecular functions utilizing information at the molecular level is important and necessary to elucidate the mechanisms of allostery, cooperativity, feed-back, etc, in biological systems and to regulate biological molecular systems by artificial functionalized molecules responsive to such information, In particular, ion recognition among molecular functions has drawn much attention, because many enzymatic activities and the transport of stimuli in nervous systems are controlled by ion binding.Thus, in this article, we describe very efficient strategies and examples to regulate the ion recognition of artificial systems utilizing a heavy metal ion, an electron, and a small organic molecule as an external effector, The first strategy is to produce a pseudocrown ether. A heavy metal ion is used as an effector. Complexation of a linear polyether bearing the metal. binding sites at the two termini gives the corresponding cyclic compound (pseudocrown ether). This methodology is very effective to control alkali metal recognition. This concept is applied to a pseudocryptand and a pseudothiacrown ether, which is a nice double recognition system for heavy metal ions. In addition, complexation with a heavy metal ion is used for regulation of molecular recognition. Secondly, redox reactions between thiol and disulfide are employed for regulation of ion recognition. Conformational change and/or change of spatial arrangement of binding site are useful for the regulation. However, these methods are not sufficient to construct perfect ah-or-none type control. The ideal regulation is successfully performed by crown ethers with a redox gate in the binding site for metal ions. The gate responds to redox reactions between thiol and disulfide to afford an open and a closed state. The open state provides a remarkably selective binding site for Ag(I). The Ag(I) selectivity is considered to result from synergistic coordination of sulfur and oxygen atoms. This is a general binding mode for the high Ag(I) selectivity of crown ethers containing sulfur atom(s). The third strategy to modulate ion recognition is molecular assembly using a receptor which has hydrogen bonding sites. A new binding site of the molecular assembly for alkali metal ion is formed from several polyether chains each of which does not exhibit binding ability toward metal ions.