Graham Jacob J, Subramani Shri V, Yang Xinyan, Russell Timothy M, Zhang Fuzhong, Keten Sinan
Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA.
Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
Sci Adv. 2025 Mar 7;11(10):eadr3833. doi: 10.1126/sciadv.adr3833.
A major challenge in synthesizing strong and tough protein fibers based on spider silk motifs is understanding the coupling between protein sequence and the postspin drawing process. We clarify how drawing-induced elongational force affects ordering, chain extension, interchain contacts, and molecular mobility through mesoscale simulations of silk-based fibers. We show that these emergent features can be used to predict mechanical property enhancements arising from postspin drawing. Simulations recapitulate a purely process-dependent mechanical property envelope in which order enhances fiber strength while preserving toughness. The relationship between chain extension and crystalline domain alignment observed in simulations is validated by Raman spectroscopy of wet-spun fibers. Property enhancements attributed to the progression of anisotropic extension are verified by mechanical tests of drawn silk fibers and justified by theory. These findings elucidate how drawing enhances properties of protein-based fibers and shed light on how to incorporate this effect into predictive models.
基于蜘蛛丝基序合成高强度和高韧性蛋白质纤维的一个主要挑战是理解蛋白质序列与纺丝后拉伸过程之间的耦合关系。我们通过对丝基纤维的中尺度模拟，阐明了拉伸诱导的伸长力如何影响有序化、链延伸、链间接触和分子流动性。我们表明，这些涌现特征可用于预测纺丝后拉伸引起的机械性能增强。模拟再现了一个纯粹依赖于过程的机械性能范围，其中有序化提高了纤维强度，同时保持了韧性。模拟中观察到的链延伸与结晶域排列之间的关系通过湿纺纤维的拉曼光谱得到了验证。通过对拉伸丝纤维的力学测试验证了归因于各向异性延伸进展的性能增强，并从理论上进行了论证。这些发现阐明了拉伸如何增强蛋白质基纤维的性能，并为如何将这种效应纳入预测模型提供了思路。
