Customizable 3D Matrix to Investigate Glycan Function

Customizable 3D Matrix to Investigate Glycan Function
PI: Matthew Brichacek; Co-I: William Gramlich, University of Maine
Abstract/Summary
Glycans in the form of glycoproteins, proteoglycans, and glycolipids provide structural support, mediate
intrinsic interactions, and facilitate extrinsic recognition allowing glycans play an integral role in cellular
pathways and disease states. Interactions of the glycans with glycan binding proteins enable these important
and diverse biological functions. However, the multivalent nature of glycan-protein interactions, as well as the
dependence on distance and orientation, have prevented the Glycoscience community from realizing the full
therapeutic potential of glycans. The proposed, customizable glycan-modified material will enable the
identification and characterization of glycans relevant to human health and explore their effects in a controlled
and customizable extracellular environment.
The first component of the customizable 3D matrix is a suite of thiol-functionalized glycans. Homogeneous glycan
substrates can be tagged with a thiol functionality using reductive amination at the reducing-end of commercially
available glycans or those obtained after fractionation of natural samples. Heterogeneous glycan pools can be
similarly prepared after oxidative or enzymatic cleavage of saccharides from biological samples. The thiol-
functionalized glycans produced offer distinct advantages over existing probes in the efficiency and
spatiotemporal control of the conjugation techniques available. These thiol-modified glycans are first validated
using a microarray of the thiol-functionalized glycans attached to a glass surface. Glycan microarrays are a
sensitive and high-throughput tool to evaluate protein-glycan binding by screening glycan binding proteins,
antibodies, whole cells, or viruses. Previous microarray investigations have identified and quantified glycan-
protein interactions using direct or indirect detection of fluorescence. However, the proposed research plan
utilizes a customizable hydrogel matrix that enables the glycan-protein interaction to be meticulously
characterized: 1) three-dimensional environment effects 2) concentration dependent behavior; and 3) synergistic
or antagonistic interactions with other glycans.
The proposed diagnostic material system is a new tool to better understand the roles that glycans play in human
physiology and disease. The identification and characterization of glycan binding proteins will validate new drug
targets and diagnostic markers in disease states and have a profound effect on human health.

Grant Number: 1R15GM157707-01
NIH Institute/Center: NIH
Principal Investigator: MATTHEW BRICHACEK