Comparative biosensing of glycosaminoglycan hyaluronic acid oligo- and polysaccharides using aerolysin and ...

Seeking new tools for the analysis of glycosaminoglycans, we have compared the translocation of anionic oligosaccharides from hyaluronic acid using aerolysin and $$-hemolysin nanopores. We show that pores of similar channel length and diameter lead to distinct translocation behavior of the same macromolecules, due to different structural properties of the nanopores. When passing from the vestibule side of the nanopores, short hyaluronic acid oligosaccharides could be detected during their translocation across an aerolysin nanopore but not across an $$-hemolysin nanopore. We were however able to detect longer oligosaccharide fragments, resulting from the in situ enzymatic depolymerization of hyaluronic acid polysaccharides, with both nanopores, meaning that short oligosaccharides were crossing the $$-hemolysin nanopore with a speed too high to be detected. The translocation speed was an order of magnitude higher across $$-hemolysin compared to aerolysin. These results show that the choice of a nanopore to be used for resistive pulse sensing experiments should not rely only on the diameter of the channel but also on other parameters such as the charge repartition within the pore lumen.