Yuan Zhaoting, Fang Bohuan, He Qixin, Wei Hao, Jian Haiming, Zhang Lujia
Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Biomacromolecules. 2025 Jan 13;26(1):601-608. doi: 10.1021/acs.biomac.4c01398. Epub 2025 Jan 2.
Spider silk is renowned for its exceptional toughness, with the strongest dragline silk composed of two proteins, MaSp1 and MaSp2, featuring central repetitive sequences and nonrepetitive terminal domains. Although these sequences to spider silk's strength and toughness, the specific roles of MaSp1 and MaSp2 at the atomic level remain unclear. Using AlphaFold3 models and molecular dynamics (MD) simulations, we constructed models of MaSp1 and MaSp2 and validated their stability. Steered molecular dynamics (SMD) simulations showed that MaSp2 resists lateral stretching, whereas MaSp1 exhibited better extensibility. During longitudinal stretching, MaSp1 formed cavities, whereas MaSp2 stretched uniformly. Hydrogen bonds involving GLN and SER in MaSp1 were strong, whereas those involving Tyr307 were prone to breakage, potentially weakening toughness. These results indicate that MaSp1 enhances extensibility, whereas MaSp2 imparts greater toughness. This study offers key molecular insights into spider silk's strength, informing the design of artificial fibers.
蜘蛛丝以其非凡的韧性而闻名，最强的拖牵丝由两种蛋白质MaSp1和MaSp2组成，具有中央重复序列和非重复末端结构域。尽管这些序列对蜘蛛丝的强度和韧性有贡献，但MaSp1和MaSp2在原子水平上的具体作用仍不清楚。利用AlphaFold3模型和分子动力学（MD）模拟，我们构建了MaSp1和MaSp2的模型并验证了它们的稳定性。定向分子动力学（SMD）模拟表明，MaSp2能抵抗横向拉伸，而MaSp1表现出更好的延展性。在纵向拉伸过程中，MaSp1形成空洞，而MaSp2均匀拉伸。MaSp1中涉及GLN和SER的氢键很强，而涉及Tyr307的氢键容易断裂，这可能会削弱韧性。这些结果表明，MaSp1增强了延展性，而MaSp2赋予了更大的韧性。这项研究为蜘蛛丝的强度提供了关键的分子见解，为人工纤维的设计提供了参考。
