UC San Diego

Glycans, and the proteins that recognize them, are involved in numerous functions throughout an organism’s lifespan. Lectins, a major group of glycan-binding proteins, typically utilize multiple glycan-binding sites to fully interact with the glycans. The specific glycans preferred by lectins in a single family can be diverse, necessitating a high-throughput method of determining lectin specificity. In this study a high-throughput microarray platform consisting of glycopolymers with varying lengths and valencies, was developed to mimic natural mucins and determine how glycan valency, density, and spatial separation affect the binding and specificity of a lectin, Ricinus Communis Agglutinin I. A variety of surfaces were evaluated, using both “Cu-click” and “Cu-free click” reactions to append the glycopolymers to the surface. Epoxysilane surfaces were functionalized with diaminoPEG under cloudpoint conditions, followed by coupling with propiolic acid for subsequent click reactions with the azide-terminated glycopolymers.

Then, the binding specificity of a lectin, Ricinus Communis agglutinin I (RCA120), was assessed using lactose and LacNAc glycopolymers of varying lengths, valency, and density on the surface. RCA120 was determined to prefer glycopolymers printed at the second-to-highest concentration, 5 μM, as well as glycopolymers ligated with N-acetyllactosamine.