Qiao Yuchen, Zia Ayisha, Shy Adrianna, Wu Grace, Chu Matthew, Liu Zhiyu, Wang Fengbin, Xu Bing
Department of Chemistry, Brandeis University, 415 South St., Waltham, Massachusetts, 02454, USA.
Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35233, USA.
Angew Chem Int Ed Engl. 2025 Jul;64(27):e202425456. doi: 10.1002/anie.202425456. Epub 2025 May 6.
Intrinsically disordered regions (IDRs) are ubiquitous in proteins, orchestrating complex cellular signaling through higher-order protein assemblies. However, the properties and functions of intrinsically disordered peptide (IDP) assemblies are largely underexplored. This work unveiled a facile strategy for engineering IDP assemblies. We demonstrate that conjugating a structured motif derived from a protein's phosphorylation site to a self-assembling tripeptide unexpectedly yields self-assembled nanofibers with intrinsic disorder. Specifically, by using a glycine linker to attach a pentapeptide derived from a phosphorylation site within a random coil region of SRC kinase to the C-terminus of a widely used self-assembling enabler, we generated a phosphorylated octapeptide. The octapeptide exhibits cell compatibility and forms a hydrogel upon dephosphorylation of the phosphooctapeptide. Cryo-electron microscopy (cryo-EM) structural analysis of the nanofibers reveals that the peptides adopt two types of helical arrangements but exhibit intrinsic disorder at the periphery of the nanofibers. The hydrogels exhibit decreased protein adsorption with increasing peptide concentration. This study represents the first instance of a structured random coil within a protein transitioning into an intrinsically disordered state within self-assembled peptide nanofibers, expanding the pool of peptide sequences for IDPs and providing valuable insights for the engineering of peptide nanofibers with intrinsic disorder for the development of cell-compatible biomaterials.
内在无序区域（IDRs）在蛋白质中普遍存在，通过高阶蛋白质组装协调复杂的细胞信号传导。然而，内在无序肽（IDP）组装体的性质和功能在很大程度上尚未得到充分探索。这项工作揭示了一种构建IDP组装体的简便策略。我们证明，将源自蛋白质磷酸化位点的结构化基序与自组装三肽偶联，意外地产生了具有内在无序性的自组装纳米纤维。具体而言，通过使用甘氨酸接头将源自SRC激酶无规卷曲区域内磷酸化位点的五肽连接到广泛使用的自组装促进剂的C末端，我们生成了一种磷酸化八肽。该八肽具有细胞相容性，并且在磷酸化八肽去磷酸化后形成水凝胶。对纳米纤维的冷冻电子显微镜（cryo-EM）结构分析表明，这些肽采用两种类型的螺旋排列，但在纳米纤维的外围表现出内在无序性。随着肽浓度的增加，水凝胶的蛋白质吸附减少。这项研究代表了蛋白质中的结构化无规卷曲转变为自组装肽纳米纤维内的内在无序状态的首个实例，扩大了IDP的肽序列库，并为开发具有细胞相容性生物材料的内在无序肽纳米纤维工程提供了有价值的见解。
