Shape-Shifting Peptide Nanomaterials: Surface Asymmetry Enables pH-Dependent Formation and Interconversion of Collagen Tubes and Sheets
Shape-Shifting Peptide Nanomaterials: Surface Asymmetry Enables pH-Dependent Formation and Interconversion of Collagen Tubes and Sheets
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DOI：
10.1021/jacs.0c08174
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发表时间：
2020-11-25
影响因子：
15
通讯作者：
Conticello, Vincent P.
中科院分区：
文献类型：
--
作者：
Merg, Andrea D.;Touponse, Gavin;Conticello, Vincent P.
对环境线索做出反应的动态可变形生物材料的制造代表了合成材料开发的重要一步，这些材料可与其高功能的天然对应物相媲美。在这里，我们描述的设计和合成的晶体超分子结构从电荷互补的异聚体对胶原蛋白模拟肽（CMP）。在适当的条件下，CMP对自发地组装成一维超多孔（孔径>100 nm）管或二维双层纳米片，这是由于异聚自缔合引起的结构不对称性。结晶胶原蛋白管代表了这种常见生物材料迄今未观察到的形态。从一套生物物理方法，包括TEM，AFM，高分辨率cryo-EM和SAXS/WAXS测量的深入结构表征，揭示了片和管组件具有类似的底层晶格结构。实验证据表明，管状结构是胶原三螺旋的初始2D层的自滚动的结果，并且滚动方向决定了两种不同结构同种型的形成。此外，我们表明，纳米片和管可以自发地相互转换，通过操纵组装pH值和系统的CMP序列的调整。总之，我们建立了初步的指导方针，建设动态响应的1D和2D组件，经历了结构编程形态的转变。
The fabrication of dynamic, transformable biomaterials that respond to environmental cues represents a significant step forward in the development of synthetic materials that rival their highly functional, natural counterparts. Here, we describe the design and synthesis of crystalline supramolecular architectures from charge-complementary heteromeric pairs of collagen-mimetic peptides (CMPs). Under appropriate conditions, CMP pairs spontaneously assemble into either 1D ultraporous (pore diameter >100 nm) tubes or 2D bilayer nanosheets due to the structural asymmetry that arises from heteromeric self-association. Crystalline collagen tubes represent a heretofore unobserved morphology of this common biomaterial. In-depth structural characterization from a suite of biophysical methods, including TEM, AFM, high-resolution cryo-EM, and SAXS/WAXS measurements, reveals that the sheet and tube assemblies possess a similar underlying lattice structure. The experimental evidence suggests that the tubular structures are a consequence of the self-scrolling of incipient 2D layers of collagen triple helices and that the scrolling direction determines the formation of two distinct structural isoforms. Furthermore, we show that nanosheets and tubes can spontaneously interconvert through manipulation of the assembly pH and systematic adjustment of the CMP sequence. Altogether, we establish initial guidelines for the construction of dynamically responsive 1D and 2D assemblies that undergo a structurally programmed morphological transition.