Experimental and computational studies reveal an alternative supramolecular structure for fmoc-dipeptide self-assembly.
Experimental and computational studies reveal an alternative supramolecular structure for fmoc-dipeptide self-assembly.
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DOI：
10.1021/bm301007r
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发表时间：
2012-11-12
影响因子：
6.2
通讯作者：
Ren, Pengyu
中科院分区：
文献类型：
--
作者：
Mu, Xiaojia;Eckes, Kevin M.;Nguyen, Mary M.;Suggs, Laura J.;Ren, Pengyu
我们采用计算和实验相结合的方法研究了芴甲氧羰基共轭二苯胺（Fmoc-AA）分子的自组装。采用TEM、圆二色谱、FTIR和WAXS对Fmoc-AA凝胶进行了表征。在计算上，我们使用分子动力学技术模拟了Fmoc-AA的组装。所有模拟都收敛到凝聚的原纤维结构，其中Fmoc基团主要堆叠在原纤维的中心内。然而，Fmoc基团部分暴露于水，产生两亲性表面，这可能是导致原纤维聚集成TEM中观察到的纳米级纤维的原因。根据原纤维模型，径向分布计算与WAXS中观察到的原纤维直径和π堆积相互作用的d间距一致。我们的分析表明，dialanine，尽管其长度短，主要采用扩展的聚脯氨酸II构象。与先前的假设相反，这些结果表明β-片层状氢键并不普遍。相反，Fmoc基团的堆叠、残基间氢键和与水的氢键在稳定短缀合肽的超分子组装体的原纤维结构中起重要作用。
We have investigated the self-assembly of fluorenylmethoxycarbonyl-conjugated dialanine (Fmoc-AA) molecules using combined computational and experimental approaches. Fmoc-AA gels were characterized using TEM, circular dichroism, FTIR, and WAXS. Computationally, we simulated the assembly of Fmoc-AA using molecular dynamics techniques. All simulations converged to a condensed fibril structure in which the Fmoc groups stack mostly within in the center of the fibril. However, the Fmoc groups are partially exposed to water, creating an amphiphilic surface, which may be responsible for aggregation of fibrils into nano-scale fibers observed in TEM. From the fibril models, radial distribution calculations agree with d-spacings observed in WAXS for the fibril diameter and π-stacking interactions. Our analyses show that dialanine, despite its short length, adopts a mainly extended polyproline II conformation. In contrast to previous hypotheses, these results indicate that β-sheet-like hydrogen bonding is not prevalent. Rather, stacking of Fmoc groups, inter-residue hydrogen bonding and hydrogen bonding with water play the important roles in stabilizing the fibril structure of supramolecular assemblies of short conjugated peptides.
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影响因子：
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作者：
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DOI：
10.1073/pnas.2335541100
发表时间：
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影响因子：
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作者：
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通讯作者：
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影响因子：
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