Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Technological Institute E136, Evanston, Illinois 60208-3120, United States.
Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, Illinois 60208-3120, United States.
ACS Synth Biol. 2020 Dec 18;9(12):3388-3399. doi: 10.1021/acssynbio.0c00442. Epub 2020 Nov 17.
Structural proteins such as "suckerins" present promising avenues for fabricating functional materials. Suckerins are a family of naturally occurring block copolymer-type proteins that comprise the sucker ring teeth of cephalopods and are known to self-assemble into supramolecular networks of nanoconfined β-sheets. Here, we report the characterization and controllable, nanoscale self-assembly of suckerin-12 (S12). We characterize the impacts of salt, pH, and protein concentration on S12 solubility, secondary structure, and self-assembly. In doing so, we identify conditions for fabricating ∼100 nm nanoassemblies (NAs) with narrow size distributions. Finally, by installing a noncanonical amino acid (ncAA) into S12, we demonstrate the assembly of NAs that are covalently conjugated with a hydrophobic fluorophore and the ability to change self-assembly and β-sheet content by PEGylation. This work presents new insights into the biochemistry of suckerin-12 and demonstrates how ncAAs can be used to expedite and fine-tune the design of protein materials.
结构蛋白，如“ suckerins ”，为制造功能性材料提供了有前景的途径。 suckerins 是一类天然存在的嵌段共聚物型蛋白质，构成头足类动物的吸盘环齿，已知它们会自组装成纳米受限β-折叠的超分子网络。在这里，我们报告了 suckerin-12（S12）的特性和可控的纳米级自组装。我们研究了盐、pH 值和蛋白质浓度对 S12 溶解度、二级结构和自组装的影响。通过这样做，我们确定了制造具有较窄尺寸分布的约 100nm 纳米组装体（NAs）的条件。最后，通过将非天然氨基酸（ncAA）引入 S12，我们展示了与疏水性荧光团共价连接的 NAs 的组装，以及通过聚乙二醇化改变自组装和β-折叠含量的能力。这项工作为 suckerin-12 的生物化学提供了新的见解，并展示了如何使用 ncAA 来加速和微调蛋白质材料的设计。
