Department of Chemical Engineering, The City College of City University of New York, 140th Street and Convent Avenue, Steinman Hall T313, New York, New York 10031, USA.
Soft Matter. 2017 Oct 25;13(41):7521-7528. doi: 10.1039/c7sm00968b.
We have designed a peptide conjugated poly-ethylene glycol (PEG) bioconjugate system that allows us to examine the intra- and inter-molecular dynamics of gelation. We measure the kinetics of gelation for end-functionalized linear- and star-architectures, and we correlate the gelation behavior with the molecular structure and self-association. The 23-amino acid peptide sequence is known to form a coiled-coil structure as a function of the solution's electrolyte concentration, and the two topologies of the PEG are peptide end-functionalized to examine formation of supramolecular assemblies. Subsequently, microrheology is used to evaluate the dynamics of self-assembly and the gelation time-scales. This study shows that the dynamics of peptide folding and assembly for linear-PEG conjugated systems yield a percolated network, but the star-PEG conjugated systems yield discrete assemblies and remain viscous. The results suggest that the degree of intra- and inter-molecular folding defines the critical gel behavior of the supramolecular system.
我们设计了一种肽连接的聚乙二醇（PEG）生物缀合物系统，使我们能够研究凝胶化的分子内和分子间动力学。我们测量了端官能化的线性和星形结构的凝胶化动力学，并将凝胶化行为与分子结构和自组装相关联。已知 23 个氨基酸肽序列作为溶液电解质浓度的函数形成卷曲螺旋结构，并且 PEG 的两种拓扑结构都被肽端官能化以检查超分子组装的形成。随后，使用微流变学评估自组装的动力学和凝胶化时间尺度。这项研究表明，线性-PEG 缀合系统中肽折叠和组装的动力学产生了一个渗透网络，但星形-PEG 缀合系统产生离散的组装体并保持粘性。结果表明，分子内和分子间折叠的程度决定了超分子系统的临界凝胶行为。
