Nanoscale Science Department, Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany;
Biomolecular Systems Department, Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany.
Proc Natl Acad Sci U S A. 2021 Jun 8;118(23). doi: 10.1073/pnas.2102168118.
Correlating the structures and properties of a polymer to its monomer sequence is key to understanding how its higher hierarchy structures are formed and how its macroscopic material properties emerge. Carbohydrate polymers, such as cellulose and chitin, are the most abundant materials found in nature whose structures and properties have been characterized only at the submicrometer level. Here, by imaging single-cellulose chains at the nanoscale, we determine the structure and local flexibility of cellulose as a function of its sequence (primary structure) and conformation (secondary structure). Changing the primary structure by chemical substitutions and geometrical variations in the secondary structure allow the chain flexibility to be engineered at the single-linkage level. Tuning local flexibility opens opportunities for the bottom-up design of carbohydrate materials.
将聚合物的结构和性质与其单体序列相关联，是理解其高级层次结构如何形成以及其宏观材料性能如何出现的关键。碳水化合物聚合物，如纤维素和壳聚糖，是自然界中最丰富的材料，其结构和性质仅在亚微米水平上得到了表征。在这里，通过在纳米尺度上成像单根纤维素链，我们确定了纤维素的结构和局部柔韧性作为其序列（一级结构）和构象（二级结构）的函数。通过在二级结构中改变化学取代和几何变化来改变一级结构，可以在单键水平上设计链的柔韧性。调整局部柔韧性为碳水化合物材料的自下而上设计提供了机会。
