Title:Rapid Differentiation of Chondroitin Sulfate Isomers by Gas-phase Hydrogen-deuterium Exchange
VOLUME: 20 ISSUE: 10
Author(s):Kimberly M. Alonge, Rick Harkewicz and Miklos Guttman*
Affiliation:University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA, Department of Medicinal Chemistry; University of Washington, Seattle, WA, Department of Medicinal Chemistry; University of Washington, Seattle, WA
Keywords:Mass spectrometry, Chondroitin sulfate, carbohydrate, gas-phase, hydrogen, deuterium, exchange
glycosaminoglycan, sulfate linkage.
Abstract:Chondroitin sulfate (CS)-glycosaminoglycans (GAGs) are linear, negatively
charged polysaccharides attached to CS proteoglycans that make up a major
component of biological matrices throughout both central and peripheral tissues. The
position of their attached sulfate groups to the CS disaccharide is predicted to influence
protein-glycan interactions and biological function. Although traditional immunohistochemical
analysis of CS-GAGs in biological tissues has provided information
regarding changes in GAG abundance during developmental and disease states,
quantitative analysis of their specific sulfation patterns is limited due to the inherent
complexity of separating CS isomers. While methods have been developed to analyze
and quantify sulfation isomers using liquid phase separation, new techniques are still
needed to elucidate the full biology of CS-GAGs. Here, we examine ion mobility
spectrometry and gas-phase hydrogen-deuterium exchange to resolve positional
sulfation isomers in the most common sulfated 4S- and 6S-CS disaccharides. The
mobilities for these two isomers are highly similar and could not be resolved effectively
with any drift gas tested. In contrast, gas-phase hydrogen-deuterium exchange showed
very different rates of deuterium uptake with several deuterium exchange reagents,
thereby presenting a promising novel and rapid approach for resolving CS isomers.
