Single‐Molecule Fluorescence Detection of a Synthetic Heparan Sulfate Disaccharide

Abstract

The first single‐molecule fluorescence detection of a structurally‐defined synthetic carbohydrate is reported: a heparan sulfate (HS) disaccharide fragment labeled with Alexa488. Single molecules have been measured whilst freely diffusing in solution and controlled encapsulation in surface‐tethered lipid vesicles has allowed extended observations of carbohydrate molecules down to the single‐molecule level. The diverse and dynamic nature of HS–protein interactions means that new tools to investigate pure HS fragments at the molecular level would significantly enhance our understanding of HS. This work is a proof‐of‐principle demonstration of the feasibility of single‐molecule studies of synthetic carbohydrates which offers a new approach to the study of pure glycosaminoglycan (GAG) fragments.

Synthesis of Heparan Sulfate- and Dermatan Sulfate-Related Oligosaccharides via Iterative Chemoselective Glycosylation Exploiting Conformationally Disarmed [2.2.2] l-Iduronic Lactone Thioglycosides

“…This thioglycoside donor group can therefore either be used to further extend the oligosaccharide chain, or to functionalize the reducing terminus of the oligosaccharide by glycosylation with a suitable acceptor. We have demonstrated such functionalization in our prior work to provide fluorescently labeled HS fragments . Following the successful demonstration here of the utility of this strategy for the synthesis of both HS-like and DS-like fragments with reducing-end donor functionality, this approach will enable access to various diverse functionalized GAG fragments with broad applications.…”

Optical detection of gadolinium(iii) ions via quantum dot aggregation

“…FCS and multichannel scalar (MCS) measurements were performed on a home-built confocal microscope with excitation at 488 nm as described previously. 13 The average laser power of the focused beam at the sample was ca. 170 μW.…”

Amyloid-β oligomerization monitored by single-molecule stepwise photobleaching

“…Of all single-molecule based techniques, the stepwise-photobleaching method, based on the long-term imaging of tracked biomolecules, has been the most widely implemented for assessing biomolecular size distributions [47] , [54] , [55] , [56] , [57] ( Fig. 2 ).…”