Taraban Marc B, Ramachandran Sivakumar, Gryczynski Ignacy, Gryczynski Zygmunt, Trewhella Jill, Yu Yihua Bruce
Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
Soft Matter. 2011;7(6):2624-2631. doi: 10.1039/C0SM00919A.
The co-assembly of mutually complementary, but self-repulsive oligopeptide pairs into viscoelastic hydrogels has been studied. Oligopeptides of 6, 10, and 14 amino acid residues were used to investigate the effects of peptide chain length on the structural and mechanical properties of the resulting hydrogels. Biophysical characterizations, including dynamic rheometry, small-angle X-ray scattering (SAXS) and fluorescence spectroscopy, were used to investigate hydrogelation at the bulk, fiber, and molecular levels, respectively. Upon mixing, the 10-mer peptides and the 14-mer peptides both form hydrogels while the 6-mer peptides do not. SAXS studies point to morphological similarity of the cross-sections of fibers underlying the 10:10 and 14:14 gels. However, fluorescence spectroscopy data suggest tighter packing of the amino acid side chains in the 10:10 fibers. Consistent with this tighter packing, dynamic rheometry data show that the 10:10 gel has much higher elastic modulus than the 14:14 mer (18 kPa vs. 0.1 kPa). Therefore, from the standpoint of mechanical strength, the optimum peptide chain length for this class of oligopeptide-based hydrogels is around 10 amino acid residues.
互补充但自排斥的寡肽对共组装成粘弹性水凝胶已得到研究。使用含有6、10和14个氨基酸残基的寡肽来研究肽链长度对所得水凝胶的结构和力学性能的影响。生物物理表征，包括动态流变学、小角X射线散射（SAXS）和荧光光谱，分别用于在整体、纤维和分子水平上研究水凝胶化。混合后，10聚体肽和14聚体肽均形成水凝胶，而6聚体肽则不形成。SAXS研究表明10:10和14:14凝胶中纤维横截面的形态相似。然而，荧光光谱数据表明10:10纤维中氨基酸侧链的堆积更紧密。与这种更紧密的堆积一致，动态流变学数据表明10:10凝胶的弹性模量比14:14聚体凝胶高得多（18 kPa对0.1 kPa）。因此，从机械强度的角度来看，这类基于寡肽的水凝胶的最佳肽链长度约为10个氨基酸残基。
