TY - JOUR A1 - Kochovski, Zdravko A1 - Chen, Guosong A1 - Yuan, Jiayin A1 - Lu, Yan T1 - Cryo-Electron microscopy for the study of self-assembled poly(ionic liquid) nanoparticles and protein supramolecular structures JF - Colloid and polymer science : official journal of the Kolloid-Gesellschaft N2 - Cryo-electron microscopy (cryo-EM) is a powerful structure determination technique that is well-suited to the study of protein and polymer self-assembly in solution. In contrast to conventional transmission electron microscopy (TEM) sample preparation, which often times involves drying and staining, the frozen-hydrated sample preparation allows the specimens to be kept and imaged in a state closest to their native one. Here, we give a short overview of the basic principles of Cryo-EM and review our results on applying it to the study of different protein and polymer self-assembled nanostructures. More specifically, we show how we have applied cryo-electron tomography (cryo-ET) to visualize the internal morphology of self-assembled poly(ionic liquid) nanoparticles and cryo-EM single particle analysis (SPA) to determine the three-dimensional (3D) structures of artificial protein microtubules. KW - self-assembly KW - poly(ionic liquid) nanoparticles KW - protein self-assembly KW - cryo-electron microscopy KW - single particle analysis KW - cryo-electron KW - tomography Y1 - 2020 U6 - https://doi.org/10.1007/s00396-020-04657-w SN - 0303-402X SN - 1435-1536 VL - 298 IS - 7 SP - 707 EP - 717 PB - Springer CY - New York ER - TY - JOUR A1 - Qi, Wenjing A1 - Zhang, Yufei A1 - Kochovski, Zdravko A1 - Wang, Jue A1 - Lu, Yan A1 - Chen, Guosong A1 - Jiang, Ming T1 - Self-assembly of Human Galectin-1 via dual supramolecular interactions and its inhibition of T-cell agglutination and apoptosis JF - Nano Research N2 - Recently, we proposed a new strategy to construct artificial plant protein assemblies, which were induced by adding a small molecule, based on dual supramolecular interactions. In this paper, we further explored this method by employing Human Galectin-1 (Gal-1) as a building block to form self-assembled microribbons. Two non-covalent interactions, including lactose-lectin binding and dimerization of Rhodamine B (RhB), induced by the small molecule ligand addition, were involved in the crosslinking of the animal protein, resulting in the formation of assemblies. By using transmission electron microscopy (TEM), cryo-electron microscopy (cryo-EM), and three-dimensional (3D) tomographic analysis, we arrived at a possible mechanistic model for the microribbon formation. Furthermore, the morphology of protein assemblies could be fine-timed by varying the incubation time, the protein/ligand ratio, and the chemical structures of ligands. Interestingly, the formation of protein microribbons successfully inhibited Gal-1 induced T-cell agglutination and apoptosis. This is because the multivalent and dynamic interactions in protein assemblies compete with the binding between Gal-1 and the glycans on cell surfaces, which suppresses the function of Gal-1 in promotion of tumor progression and metastasis. KW - protein self-assembly KW - supramolecular interactions KW - galectin KW - cell agglutination Y1 - 2018 U6 - https://doi.org/10.1007/s12274-018-2169-7 SN - 1998-0124 SN - 1998-0000 VL - 11 IS - 10 SP - 5566 EP - 5572 PB - Tsinghua Univ Press CY - Beijing ER - TY - JOUR A1 - Yang, Guang A1 - Ding, Hong-ming A1 - Kochovski, Zdravko A1 - Hu, Rongting A1 - Lu, Yan A1 - Ma, Yu-qiang A1 - Chen, Guosong A1 - Jiang, Ming T1 - Highly Ordered Self-Assembly of Native Proteins into 1D, 2D, and 3D Structures Modulated by the Tether Length of Assembly-Inducing Ligands JF - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition N2 - In nature, proteins self-assemble into various structures with different dimensions. To construct these nanostructures in laboratories, normally proteins with different symmetries are selected. However, most of these approaches are engineering-intensive and highly dependent on the accuracy of the protein design. Herein, we report that a simple native protein LecA assembles into one-dimensional nanoribbons and nanowires, two-dimensional nanosheets, and three-dimensional layered structures controlled mainly by small-molecule assembly-inducing ligands RnG (n = 1, 2, 3, 4, 5) with varying numbers of ethylene oxide repeating units. To understand the formation mechanism of the different morphologies controlled by the small-molecule structure, molecular simulations were performed from microscopic and mesoscopic view, which presented a clear relationship between the molecular structure of the ligands and the assembled patterns. These results introduce an easy strategy to control the assembly structure and dimension, which could shed light on controlled protein assembly. KW - carbohydrate-protein interactions KW - dual non-covalent interactions KW - molecular simulations KW - protein self-assembly Y1 - 2017 U6 - https://doi.org/10.1002/anie.201703052 SN - 1433-7851 SN - 1521-3773 VL - 56 SP - 10691 EP - 10695 PB - Wiley-VCH CY - Weinheim ER -