State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China.
State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China.
J Colloid Interface Sci. 2025 Jan 15;678(Pt B):854-865. doi: 10.1016/j.jcis.2024.09.065. Epub 2024 Sep 10.
The self-assembling morphologies of proteins, nucleic acids, and peptides are well correlated with their functioning in biological systems. In spite of extensive studies for the morphologies regulating, the directional control of the assembly morphology structure for the peptides still remains challenging. Here, the directional structure control of a bola-like peptide Ac-KIIF-CONH (KIIF) was realized by introducing different amount of acetonitrile to the system. The morphologies were characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM), and the secondary structure was evaluated by circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR). The results demonstrated that the introducing of different amount of acetonitrile has significantly tuned the hydrophobic interactions amongst the side chains, thus affecting the self-assembling morphologies. As acetonitrile content increased, the assemblies changed from nanotubes to helical/twisted ribbons and then to thin fibrils, with a steady decrease in the width. In contrast, the assemblies changed from thin fibrils to helical/twisted ribbons, and then to matured nanotubes, exhibiting a steady increase in the width with peptide concentration increasing. Complementary molecular dynamics (MD) simulations demonstrated the important role of acetonitrile in controlling the hydrophobic interactions, providing microscopic evidence for the structure transition process. We believe such observations provide important insights into the design and fabrication of functional materials with controlled shape and size.
蛋白质、核酸和肽的自组装形态与其在生物系统中的功能密切相关。尽管已经进行了广泛的研究来调节形态，但肽的组装形态结构的定向控制仍然具有挑战性。在这里，通过向体系中引入不同量的乙腈，实现了类 bola 肽 Ac-KIIF-CONH（KIIF）的定向结构控制。通过透射电子显微镜（TEM）和原子力显微镜（AFM）对形态进行了表征，并通过圆二色性（CD）和傅里叶变换红外光谱（FTIR）评估了二级结构。结果表明，引入不同量的乙腈可以显著调节侧链之间的疏水相互作用，从而影响自组装形态。随着乙腈含量的增加，组装体从纳米管变为螺旋/扭曲的带状物，然后变为细纤维，宽度逐渐减小。相比之下，组装体从细纤维变为螺旋/扭曲的带状物，然后变为成熟的纳米管，随着肽浓度的增加，宽度逐渐增加。补充的分子动力学（MD）模拟表明，乙腈在控制疏水相互作用方面发挥了重要作用，为结构转变过程提供了微观证据。我们相信，这些观察结果为具有可控形状和尺寸的功能材料的设计和制造提供了重要的见解。
