A High‐Throughput SPR‐Based Array for Quantitative Profiling of Glycosaminoglycan–Protein Interactions

ABSTRACT Glycosaminoglycans (GAGs) are linear, negatively charged, polysaccharides that mediate a wide variety of biologically critical interactions with proteins, underpinning growth factor signaling, extracellular matrix assembly, and numerous disease processes. However, GAG–protein interactions remain undercharacterized, in part because of the lack of high‐throughput tools to systematically profile binding across the GAG interactome. In this paper, we present a novel Surface Plasmon Resonance‐based array methodology utilizing 16 commonly sourced GAG preparations (including chondroitin sulfate (CS), dermatan sulfate (DS), heparan sulfate, heparin, hyaluronan, and keratan sulfate), allowing the specificity and affinity of GAG‐binding proteins to be determined. As proof of principle, we have validated the array using four established GAG‐binding proteins (antithrombin III, CD44, heavy chain 1 from inter‐α‐inhibitor, and Slit2), generating data consistent with the known binding specificities and quantifying affinities for many of the interactions. The array also reveals previously unreported GAG interactions, including Slit2 binding to CS and DS, and CD44 binding to chondroitin sulfate E.