Carbohydrate-protein interactions are essential for a wide range of biological processes such as inflammation, bacterial and viral adhesion, and metastasis. As a result, there has been significant interest in identifying carbohydrate binding proteins and developing ligands to modulate their activity. Analysis of carbohydrate-protein interactions is complicated by a number of factors. First, carbohydrates are extremely difficult to isolate or synthesize. Therefore, only small amounts can be obtained in many cases. Second, traditional methods for studying binding are not high-throughput and require large amounts of material. Third, monovalent interactions between carbohydrates and proteins are notoriously weak. To achieve a high avidity, carbohydrate-binding proteins contain multiple binding sites and form multivalent complexes. As a result, carbohydrates must be presented in a multivalent fashion and the spacing and orientation of the carbohydrates play a critical role in recognition. Carbohydrate microarrays, or glycan arrays, contain many different carbohydrates, or glycans, immobilized on a solid support in a spatially-defined arrangement. Using an array, one can evaluate binding of a lectin, antibody, cell, or virus to all the carbohydrates on the array simultaneously. The array provides a multivalent presentation of carbohydrates, and the miniaturized format requires only picogram amounts of each carbohydrate for an assay. We have developed a novel glycan array format utilizing neoglycoproteins. Neoglycoproteins are multivalent conjugates wherein carbohydrates are covalently attached to a carrier protein, such as bovine serum albumin. These neoglycoproteins, as well as natural glycoproteins, are printed onto epoxide coated microscope slides using a robotic microarrayer to produce microarrays. Neoglycoproteins can be used as multivalent reagents for other assays such as ELISAs, as multivalent inhibitors, and as multivalent immunogens. We currently have one of the largest and most unique glycan arrays in the world. Recently, we have focused on expanding and improving the carbohydrate microarray. One objective is to increase the number of glycans on the array. We have been developing improved synthetic methods for preparing glycopeptides. The methodology will be used to prepare a large library of glycopeptides for addition to the array. in addition, we are optimizing methods to conjugate carbohydrates to proteins to produce neoglycoproteins.
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| Xia, Li; Gildersleeve, Jeffrey C (2015) The Glycan Array Platform as a Tool to Identify Carbohydrate Antigens. Methods Mol Biol 1331:27-40 |
| Wang, Linlin; Cummings, Richard D; Smith, David F et al. (2014) Cross-platform comparison of glycan microarray formats. Glycobiology 24:507-17 |
| Park, Sungjin; Gildersleeve, Jeffrey C; Blixt, Ola et al. (2013) Carbohydrate microarrays. Chem Soc Rev 42:4310-26 |
| Zhang, Yalong; Muthana, Saddam M; Barchi Jr, Joseph J et al. (2012) Divergent behavior of glycosylated threonine and serine derivatives in solid phase peptide synthesis. Org Lett 14:3958-61 |
| Zhang, Yalong; Muthana, Saddam M; Farnsworth, David et al. (2012) Enhanced epimerization of glycosylated amino acids during solid-phase peptide synthesis. J Am Chem Soc 134:6316-25 |
| Zhang, Yalong; Gildersleeve, Jeffrey C (2012) General procedure for the synthesis of neoglycoproteins and immobilization on epoxide-modified glass slides. Methods Mol Biol 808:155-65 |
| Campbell, Christopher T; Zhang, Yalong; Gildersleeve, Jeffrey C (2010) Construction and use of glycan microarrays. Curr Protoc Chem Biol 2:37-53 |
| Zhang, Yalong; Li, Qian; Rodriguez, Luis G et al. (2010) An array-based method to identify multivalent inhibitors. J Am Chem Soc 132:9653-62 |
| Ludek, Olaf R; Gu, Wenlu; Gildersleeve, Jeffrey C (2010) Activation of glycosyl trichloroacetimidates with perchloric acid on silica (HClO(4)-SiO(2)) provides enhanced alpha-selectivity. Carbohydr Res 345:2074-8 |
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