Ling Shengjie, Dinjaski Nina, Ebrahimi Davoud, Wong Joyce Y, Kaplan David L, Buehler Markus J
Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.
Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States.
ACS Biomater Sci Eng. 2016 Aug 8;2(8):1298-1308. doi: 10.1021/acsbiomaterials.6b00234. Epub 2016 Jul 1.
Current trends in biomaterial designs require a detailed understanding of structure-function relationships to efficiently address specific utilities. As a prototype, spider silk has been widely studied with diversified characterization or simulation methods, exploiting the integration of experimental and modeling approaches to gain insight into structure-function relationships. However, the assembly mechanisms of spider silk in natural and non-natural environments remain incompletely understood. In the present study, experimental and simulation approaches were utilized to study assembly mechanisms of recombinant spider silks. Two spider silk constructs, H(AB) and H(AB)NtSp, were produced and studied. Deconvoluted Fourier transform infrared spectroscopy (FTIR) spectra and molecular dynamics simulations, before and after ethanol treatment, were analyzed to quantify secondary structures, and a higher helix content was observed in H(AB)NtSp compared with that in H(AB). Time-resolved FTIR analysis was used to monitor conformation transitions. A higher rate of β-sheet formation was found in H(AB)NtSp compared with that in H(AB). These results suggest that the N-terminal domain accelerates self-assembly of recombinant spidroins under ethanol treatment. The approaches used in this study provide insights into the function of the N-terminal domain in conformational transitions of spider silks under non-natural conditions as well as fiber formation. This approach should enable more efficient design, synthesis, and preparation of new recombinant spidroin materials with tunable mechanical properties.
生物材料设计的当前趋势要求详细了解结构 - 功能关系，以便有效地满足特定用途。作为一个原型，蜘蛛丝已通过多种表征或模拟方法进行了广泛研究，利用实验和建模方法的结合来深入了解结构 - 功能关系。然而，蜘蛛丝在自然和非自然环境中的组装机制仍未完全了解。在本研究中，利用实验和模拟方法来研究重组蜘蛛丝的组装机制。制备并研究了两种蜘蛛丝构建体，即H(AB)和H(AB)NtSp。对乙醇处理前后的去卷积傅里叶变换红外光谱(FTIR)光谱和分子动力学模拟进行分析，以量化二级结构，结果表明与H(AB)相比，H(AB)NtSp中观察到更高的螺旋含量。使用时间分辨FTIR分析来监测构象转变。结果发现，与H(AB)相比，H(AB)NtSp中β-折叠形成的速率更高。这些结果表明，在乙醇处理下，N端结构域加速了重组蛛丝蛋白的自组装。本研究中使用的方法为非自然条件下蜘蛛丝构象转变以及纤维形成过程中N端结构域的功能提供了见解。这种方法应能实现更高效地设计、合成和制备具有可调机械性能的新型重组蛛丝蛋白材料。
