Detecting Protein-Glycolipid Interactions using Glycomicelles and CaR-ESI-MS

摘要

High affinity interaction of CTB_5 and GM1 glycomicelle was revealed by CaR-ESI-MS assay. However, the apparent affinity is significantly lower than that of corresponding GM1_(os) or GM1 nanodiscs. No binding of CTB_5 to GM2 or GM3 glycomicelle was observed. In the absence of GM1, very little ganglioside-bound CTB_6 was detected suggesting that CTB_5-ganglioside binding (specific or non-specific) is enhanced by the presence of the high affinity GM1. Nonspecific binding during ESI process could be responsible for CTB_5 interactions with GD1a, GD1b, GT1b and GD2 glycomicelles in that corresponding nonspecific interactions were observed for Stx1B_5.