Peptide flat-rod formation by precise arrangement among enantiomeric hydrophobic helices
Peptide flat-rod formation by precise arrangement among enantiomeric hydrophobic helices
复制标题
通过对映体疏水性螺旋之间的精确排列形成肽扁杆
DOI：
10.1016/j.jcis.2022.02.141
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发表时间：
2022
影响因子：
9.9
通讯作者：
Ueda Motoki
中科院分区：
文献类型：
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作者：
Itagaki Toru;Ito Yoshihiro;Ueda Motoki
对分子排列的精确控制是功能性分子组装的关键。报道了一种线型(I型)两亲性嵌段共聚肽-聚肌氨酸-b-(L-亮氨酸-Alb)6(I-SL12)，它具有亲水性的聚肌氨酸(Psar)链和疏水的螺旋嵌段，通过规则地堆积亮氨酸侧链自组装成纳米管。在这里，我们合成了一种T型两亲性嵌段共聚肽(l-Leu-Aib)3-AzF(PSar)-Aib-(l-Leu-Aib)2(T-SL12)，，研究了分子几何结构对分子组装形态的影响。与传统的I-SL12不同，T-SL12可以自组装成螺旋纳米管。T-SL12(右旋螺旋)和聚肌氨酸-b-(d-亮氨酸-AIB)6(I-SdL12，左旋螺旋)的混合物形成了扁平的棒状结构，而T-SL12和I-SL12(都是右旋)的混合物形成了直径80 nm的纳米管。这一结果表明T-SL12和I-SdL12之间形成了立体络合物。当T-SdL12和I-SdL12的比例为1：1~1：3(wt/wt)时，虽然其宽度(约12 nm)和长度(50-200 nm)不随化学计量比的变化而变化，但得到了多肽扁棒。用原子力显微镜测量了扁棒的厚度(6 Nm)。根据这些维度，我们认为多肽扁棒的短轴是由两个立体络合的杂二聚体T-SL12和I-SdL12通过使I-SdL12相互朝向而组成的，并且这个四肽单元在长轴上是并排重复的。
Precise control of molecular arrangement is essential for functional molecular assemblies. A linear (I-shaped) amphiphilic block copolypeptide, polysarcosine-b-(l-Leu-Aib)6(I-SL12), which has a hydrophilic polysarcosine (PSar) chain and a hydrophobic helical block, was reported to self-assemble into nanotubes by regular packing of the Leu side chains. Here, we have synthesized a T-shaped amphiphilic block copolypeptide, (l-Leu-Aib)3-AzF(PSar)-Aib-(l-Leu-Aib)2(T-SL12), to investigate the effect of molecular geometry on the morphology of molecular assemblies. Unlike conventional I-SL12, T-SL12 self-assembles into helical nanotubes. A mixture of T-SL12 (a right-handed helix) and polysarcosine-b-(d-Leu-Aib)6(I-SdL12, a left-handed helix) formed flat rod-shaped structures, while the mixture of T-SL12 and I-SL12 (both right-handed) forms nanotubes with an 80-nm diameter. This result indicates that stereo-complexes was formed between T-SL12 and I-SdL12. Peptidic flat-rod were obtained at ratios of T-SL12 and I-SdL12 from 1:1 to 1:3 (wt/wt), although their width (ca. 12 nm) and length (50–200 nm) did not change with stoichiometry. The thickness (6 nm) of the flat rod was measured by AFM. From these dimensions, we propose that the minor axis of peptidic flat-rod is composed of two stereo-complexed heterodimers of T-SL12 and I-SdL12 by orienting the I-SdL12s facing each other, and that this four-peptide unit is repeated side-by-side along the long axis.