화학공학소재연구정보센터
Nature, Vol.582, No.7812, 375-+, 2020
Imaging single glycans
Imaging of biomolecules guides our understanding of their diverse structures and functions(1,2). Real-space imaging at sub-nanometre resolution using cryo-electron microscopy has provided key insights into proteins and their assemblies(3,4). Direct molecular imaging of glycans-the predominant biopolymers on Earth, with a plethora of structural and biological functions(5)-has not been possible so far(6). The inherent glycan complexity and backbone flexibility require single-molecule approaches for real-space imaging. At present, glycan characterization often relies on a combination of mass spectrometry and nuclear magnetic resonance imaging to provide insights into size, sequence, branching and connectivity, and therefore requires structure reconstruction from indirect information(7-9). Here we show direct imaging of single glycan molecules that are isolated by mass-selective, soft-landing electrospray ion beam deposition and imaged by low-temperature scanning tunnelling microscopy(10). The sub-nanometre resolution of the technique enables the visualization of glycan connectivity and discrimination between regioisomers. Direct glycan imaging is an important step towards a better understanding of the structure of carbohydrates.