An artificial molecular chaperone: poly-pseudo-rotaxane with an extensible axle.
An artificial molecular chaperone: poly-pseudo-rotaxane with an extensible axle.
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DOI：
10.1021/ja075140o
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发表时间：
2007-10
影响因子：
15
通讯作者：
Motofumi Osaki;Y. Takashima;H. Yamaguchi;A. Harada
中科院分区：
文献类型：
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作者：
Motofumi Osaki;Y. Takashima;H. Yamaguchi;A. Harada
当CD（α-CD、β-CD和2，6-二-O-甲基-β-CD）穿入聚合物链时，聚-假轮烷CD包含作为子集1（CD;环糊精，1;在聚合物链末端具有单个β-CD的聚（δ-戊内酯））引发固态δ-戊内酯（δ-VL）的聚合。没有螺纹CD的1没有显示出任何聚合能力的δ-VL。金刚烷分子（Ad）抑制CD作为亚群1包含的聚合能力，表明CD作为亚群1包含的末端的β-CD不能结合δ-VL，因为β-CD空腔被Ad占据。应该注意的是，插入反应和聚合发生在CD末端的β-CD空腔内，包含子集1，并且聚假轮烷的形成对于引发delta-VL是必要的。通过粉末X射线衍射测量和固态NMR光谱表征β-CD包含作为子集1和1的结构。发现β-CD的聚合物链作为子集1在固态下伸长，而1的聚合物链形成无规卷曲构象。1通过用聚合物链阻断β-CD的活性腔而使聚合失活。穿线到1上的CD直接对delta-VL的起始免疫，但作为人工伴侣以适当的方式折叠聚合物链具有重要作用。
Poly-pseudo-rotaxanes CDs contains as a subset 1 (CDs; cyclodextrins, 1; poly(delta-valerolactone) having single beta-CD at the end of the polymer chain) initiate polymerization of delta-valerolactone (delta-VL) in the solid state when CDs (alpha-CD, beta-CD, and 2,6-di-O-methyl-beta-CD) are threaded onto the polymer chain. 1 without threaded CDs did not show any polymerization ability for delta-VL. An adamantane molecule (Ad) inhibited the polymerization ability of CDs contains as a subset 1 for delta-VL, indicating that beta-CD at the end of CDs contains as a subset 1 could not bind delta-VL because the beta-CD cavity was occupied by Ad. It should be noted that the insertion reaction and the polymerization took place inside the beta-CD cavity at the end of CDs contains as a subset 1 and that the formation of poly-pseudo-rotaxane is necessary for the initiation of delta-VL. The structures of beta-CD contains as a subset 1 and 1 were characterized by powder X-ray diffraction measurements and solid-state NMR spectroscopies. The polymer chain of beta-CD contains as a subset 1 was found to elongate in the solid state, whereas the polymer chain of 1 formed a random coil conformation. 1 was deactivated for the polymerization by blocking the active cavity of beta-CD with the polymer chain. CDs threaded onto 1 are immune to the initiation of delta-VL directly but have an essential role to fold the polymer chain in a proper way as an artificial chaperone.