| POLYMERS Vol.62 No.9 |
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特集
挑战高分子的折叠技术 |
| 展望 |
| 人工螺旋高分子的设计与功能体现-最新进展- | 逢坂直树，八岛荣次 |
| <Abstract>
螺旋高分子其结构本身就是手性结构，故多种多样主链结构的螺旋高分子因其手性结构显示出多种特异功能而备受人们关注。本文论述了螺旋结构合成的最新进展，结构解析，应用及今后的展望等。 Keywords: Helical Structure / Chirality / Double Helix / Asymmetric Catalyst / Molecular Spring |
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| 蛋白质的折叠: 理想与现实 | 田口英树 |
| <Abstract>
作为生物高分子的蛋白质是由20多种氨基酸组成的多肽链形成特殊立体结构（折叠）而发挥其功能的。本文概述了关于蛋白质的折叠及细胞内助其折叠的侣伴蛋白的最新热门课题。 Keywords: Protein Folding / Chaperones / Chaperonin / GroEL / Aggregation / Cell-Free Translation |
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| 人工分子伴侣蛋白系统 | 佐佐木善浩，秋吉一成 |
| <Abstract>
蛋白质的高效生产及稳定化的技术，可长期释放的药物传输系统（DDS）的开发等是蛋白质工程和再生医疗领域中的非常重要的课题。本文介绍了以天然分子伴侣蛋白为参照体系，能够帮助蛋白质折叠的人工伴侣蛋白的合成开发及其在生物医疗领域中的应用。 Keywords: Polysaccharide Nanogel / Artificial Molecular Chaperone / Membrane Protein / Cell-Free Protein Synthesis |
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| 话题 |
| 无规聚合物链的有序控制：大分子折叠的一种新方法 | Jean-Francçis Lutz |
| <Abstract>
Atactic synthetic polymer chains are, in general, amorphous materials in the solid state and in solution. However, when functionalized on their side chains by associating motifs (e.g. crystalline side-chains, self-assembling supramolecular motifs, reactive functions leading to covalent bridges), atactic polymers can be organized into more ordered materials. In particular, structured globular single-chain object can be formed in solution. Such ‘compaction’ approaches follow design principles that are very different from those that govern the folding of natural proteins or synthetic foldamers. Nevertheless, these novel strategies open up very interesting avenues for single-chain materials design. This exciting new field of research is briefly presented in this short review. Keywords: Polymer Folding / Precision Polymers / Sequence-Controlled Polymers / Single-Chain Technology / Single-Chain Particles |
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| 合成螺旋分子的热滞效应：分子等级的记忆效果 | 重野真德，山口雅彦 |
| <Abstract> Thermal hysteresis is a phenomenon, in which different responses occur during heating and cooling. Although bulk materials can exhibit thermal hysteresis by strong and multiple cooperative interactions between molecules, thermal hysteresis at molecular level in nonpolar organic solvents was essentially not known until now. We found that a chiral sulfonamido helicene tetramer forms a helix dimer in 1,3-difluorobenzene, which unfolds to a random coil on heating. This structural change exhibited thermal hysteresis, in which different structures of a helix dimer and a random coil were formed during heating and cooling at the same temperature. The phenomenon was explained by the different populations of helix dimers and random coils at the same temperature, and by the presence of induction periods. Thermal hysteresis is related to the “memory effect”: the molecules memorize their thermal history, whether they were heated or cooled in the past. The model can also explain the “memory effect”. Keywords: Molecular Thermal Hysteresis / Memory Effect / Induction Period / Helicenes / Helix Dimer / Sulfonamides |
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| SNA：通过序列设计可控制螺旋结构的核算类似物 | 浅沼浩之，村山惠司，檻田啓 |
| <Abstract> We synthesized a unique nucleic acid analogue, Serinol Nucleic Acid (SNA), from a serinol scaffold tethering natural nucleobases through an amide bond. The SNA oligomer that is fully synthesized from four chiral SNA monomers changes its chirality by the sequence design, not by the inherent chirality of monomers: The SNA oligomer with an asymmetric sequence is chiral whereas the symmetric one is achiral. The chirality of the SNA oligomer can be inverted by reversing its sequence, i.e., two enantiomers of SNA oligomers can be synthesized from four monomers with the identical chirality. Interestingly, SNA formed a remarkably stable duplex with a complementary SNA in an antiparallel manner with its helicity depending on the sequence, which is much more stable than the corresponding DNA/DNA or RNA/RNA duplex. More interestingly, SNA also formed a stable duplex both with DNA and RNA, indicating high potential for antisense agents. These unique properties of SNA might provide an insight for why d-ribose was selected as a scaffold for natural nucleic acids. Keywords: Nucleic Acid Analogue / Serinol Nucleic Acid / Chirality / Helicity/ Cross-Pairing / Antisense Agent |
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| 有机纳米管凝胶的伴侣功能 | 龟田直弘 |
| <Abstract> Self-organization of synthetic lipids in water produced nanotube hydrogels in the presence of chemically denatured proteins at room temperature, which were able to encapsulate the proteins in the nanotube channel. Decreasing the concentrations of the denaturants induced refolding of part of the encapsulated proteins in the nanotube channel. Changing the pH dramatically reduced electrostatic attraction between the inner surface mainly covered with amino groups of the nanotube channel and the encapsulated proteins. As the result, the refolded proteins were smoothly released into the bulk solution without specific additive agents. This recovery procedure also transformed the encapsulated proteins from an intermediately refolding state to a completely refolded state. Introduction of hydrophobic groups onto the inner surface of the nanotube channel remarkably enhanced the encapsulation and refolding efficiencies. Refolding was also strongly dependent on the inner diameters of the nanotube channels. Thus, the nanotube hydrogels assisted the refolding of the denatured proteins and acted as artificial chaperones. Keywords: Organic Nanotubes / Nanochannel / Self-Organization / Hydrogels / Chaperones / Refolding / Proteins / Enzymes |
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| 高分子科学与我：个人独白 |
| 无规卷曲聚合物的行踪？ | 川口大辅 |
| <Abstract> My winding life has been just like a contour of a random-coil polymer so far. In this essay, I write my personal and research backgrounds and my ambition for the future. |
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| 高分子科学的最新进展 |
| 通过界面反应合成的具有规则纳米结构的高分子 | 国武雅司 |
| <Abstract> The construction of sophisticated, supramolecular architectures through self-assembly has attracted considerable attention as “bottom-up” nanotechnology. The pursuit of methods for design and preparation of robust nanoarchitectonic systems with integrated various functionality through bottom-up methodologies remains a driving force in molecular nanotechnology. Novel polymer materials bearing unique well-defined chemical structures prepared by chemical reaction at the interfaces are introduced. Thermodynamic self-assembly of 1-D and 2-D π-conjugated covalent nanoarchitectures were independently achieved by thermal treatment in ultra high vacuum and “on-site” equilibrium successive polymerization at solid-liquid interfaces. Keywords: Bottom-up Nanotechnology / Soft Solution Process / Covalent Organic Framework / Thermodynamic Self-Assembly / UHV / STM |
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