Single Molecule Visualization of Chitin/Chitosan Structures and their Protein Interactions

甲壳素/壳聚糖结构及其蛋白质相互作用的单分子可视化

• 批准号: 525894403
• 负责人: Dr. Kelvin Anggara
• 金额: --
• 依托单位: Abteilung Nanowissenschaften
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/525894403?language=en
• 关键词: Single; Molecule; Visualization; Chitin; Chitosan

This project aims to develop tools to analyze structures of chitin/chitosan and their protein interactions at single molecule level. Chitin and chitosan are the most abundant biomolecules on Earth after cellulose. Chitin/chitosan polysaccharides are important structural materials and signaling molecules in many living systems, and they have vital commercial uses due to their low cost and biocompatibility. Despite their importance and ubiquity, however, little is known about chitin/chitosan structures and how they translate to chitin/chitosan properties, due to difficulties in analyzing their structures by ensemble averaged analytical techniques. Given that chitin is a long, linear chain of acetylated monosaccharides while chitosan is a copolymer of acetylated and non-acetylated monosaccharides, ensemble averaged methods are unable to provide information on acetylation pattern/motif present along individual chitin/chitosan chains. Difficulties in analyzing these polysaccharides by ensemble averaged methods are further exacerbated by their extensive structural variations among individual molecules. The challenge of unveiling chitin/chitosan structures and interactions calls for a direct, single molecule approach. This project confronts this challenge by using direct imaging of chitin/chitosan to unveil their structures and interactions at single molecule level. Chitin/chitosan are electrosprayed as ions in gas phase which are subsequently landed intact at a surface and imaged individually by scanning tunnelling microscopy at submolecular resolution. By imaging single chitin/chitosan chains at the nanoscale, we aim to reveal the acetylation sequence, the shape/folding, and the interactions of individual chitin/chitosan chains. Specifically, three systems will be investigated, namely (1) chitin/chitosan oligosaccharides, (2) chitin/chitosan polysaccharides, and (3) protein – chitin/chitosan adducts. Direct nanoscale imaging of chitin/chitosan is anticipated to unveil structural motifs that facilitate their binding to diverse proteins which initiate or regulate biological functions, as well as motifs that give rise to rich physical properties of chitin/chitosan materials. Understanding chitin/chitosan structures and interactions at single molecule level will provide the molecular basis to understand the diverse chitin/chitosan properties, thereby contributing towards the development of new therapeutic strategies and functional materials based on chitin and chitosan.

本项目旨在开发工具在单分子水平上分析甲壳素/壳聚糖的结构和它们之间的蛋白质相互作用。甲壳素和壳聚糖是地球上仅次于纤维素的最丰富的生物分子。甲壳素/壳聚糖是许多生命系统中重要的结构材料和信号分子，具有低成本和生物相容性，具有重要的商业应用价值。然而，尽管甲壳素/壳聚糖结构的重要性和普遍性，以及它们如何转化为甲壳素/壳聚糖的性质，人们对它们知之甚少，因为很难用集合平均分析技术来分析它们的结构。鉴于甲壳素是乙酰化单糖的长线性链，而壳聚糖是乙酰化和非乙酰化单糖的共聚物，总体平均方法无法提供关于个别甲壳素/壳聚糖链上存在的乙酰化模式/基序的信息。这些多糖在单个分子之间的广泛结构差异进一步加剧了用集合平均方法分析这些多糖的困难。揭示甲壳素/壳聚糖的结构和相互作用的挑战需要一种直接的单分子方法。本项目通过利用甲壳素/壳聚糖的直接成像在单分子水平上揭示它们的结构和相互作用来面对这一挑战。甲壳素/壳聚糖在气相中以离子的形式电喷雾，然后完好无损地落在表面，并在亚分子分辨率下通过扫描隧道显微镜单独成像。通过在纳米尺度上对甲壳素/壳聚糖单链进行成像，我们旨在揭示单个甲壳素/壳聚糖链的乙酰化顺序、形状/折叠以及相互作用。具体地说，将研究三个体系，即(1)甲壳素/壳低聚糖，(2)甲壳素/壳聚糖，和(3)蛋白质-甲壳素/壳聚糖加合物。甲壳素/壳聚糖的直接纳米成像有望揭示其与启动或调节生物功能的不同蛋白质结合的结构基序，以及产生甲壳素/壳聚糖材料丰富物理性质的基序。在单分子水平上了解甲壳素/壳聚糖的结构和相互作用将为理解甲壳素/壳聚糖不同的性质提供分子基础，从而有助于开发基于甲壳素和壳聚糖的新的治疗策略和功能材料。