Departments of Chemistry and Bioengineering Rice University, Houston, Texas 77005, USA.
Nat Chem. 2011 Aug 28;3(10):821-8. doi: 10.1038/nchem.1123.
Replicating the multi-hierarchical self-assembly of collagen has long-attracted scientists, from both the perspective of the fundamental science of supramolecular chemistry and that of potential biomedical applications in tissue engineering. Many approaches to drive the self-assembly of synthetic systems through the same steps as those of natural collagen (peptide chain to triple helix to nanofibres and, finally, to a hydrogel) are partially successful, but none simultaneously demonstrate all the levels of structural assembly. Here we describe a peptide that replicates the self-assembly of collagen through each of these steps. The peptide features collagen's characteristic proline-hydroxyproline-glycine repeating unit, complemented by designed salt-bridged hydrogen bonds between lysine and aspartate to stabilize the triple helix in a sticky-ended assembly. This assembly is propagated into nanofibres with characteristic triple helical packing and lengths with a lower bound of several hundred nanometres. These nanofibres form a hydrogel that is degraded by collagenase at a similar rate to that of natural collagen.
胶原的多层次自组装一直吸引着科学家，从超分子化学的基础科学角度和组织工程中潜在的生物医学应用角度来看都是如此。许多方法试图通过与天然胶原相同的步骤来驱动合成体系的自组装（肽链到三螺旋到纳米纤维，最后到水凝胶），这些方法在一定程度上取得了成功，但没有一种方法能同时展示所有结构组装层次。在这里，我们描述了一种能够通过这些步骤复制胶原自组装的肽。该肽具有胶原特有的脯氨酸-羟脯氨酸-甘氨酸重复单元，并通过赖氨酸和天冬氨酸之间设计的盐桥氢键进行补充，以稳定粘性末端组装中的三螺旋。这种组装进一步延伸成具有特征性三螺旋包装和数百纳米下限长度的纳米纤维。这些纳米纤维形成水凝胶，其被胶原酶降解的速度与天然胶原相似。
