Project Details
Projekt
Single Molecule Visualization of Chitin/Chitosan Structures and their Protein Interactions
Applicant
Dr. Kelvin Anggara
Subject Area
Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
Analytical Chemistry
Analytical Chemistry
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 525894403
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.
DFG Programme
Priority Programmes
