The natural mucin ligands for cell adhesion proteins (L- & P-selectin) and various tumor-associated core 2, 0-linked glycoproteins are known to contain the Galb1->4GlcNAcb1-6(Galb1-3)GalNAca-> structure. Relatively little is known of the precise substrate specificities of the glycosyltransferases that can modify this moiety. This proposal is centered on the study of selected glycosyltransferases which act on two galactose residues (Galb1-4 and Galb1-3) of this branched tetrasaccharide. Our prime interest is to study 2,3-sialyltransferases. We have also included the study of two a1,2-fucosyltransferases and a1,4GlcNAc-transferases. One unique and common characteristic of these enzymes is that they prefer this core 2, branched structure for their activities over the simple Galbl-4GlcNAcb and Galbl 3GalNAca disaccharides. We plan to procure a series of core 2 branched structures and other structures which occur as a part of glycoproteins and glycolipids for investigating the specificity of these enzymes. We will examine the specificity of different a2,3-sialyltransferases and ST3Gal I - IV. We also plan to purify these enzymes from selected sources and examine their specificity with a spectrum of compounds. Our rationale for the study of these enzymes is that the combined knowledge of their actions will enable us to elucidate the biosynthetic pathways of; e.g. Fuca1 -2Galbl->GlcNAcbl-6(NeuAca2-3Galb1-3)GalNAca1-, as found in 0-linked glycoproteins. We also hypothesize that the combined knowledge of these enzymes from a given tumor tissue or cell line source will provide us information on the structures of oligosaccharide moieties which can occur as part of tumor-associated antigens. Thus, as a long term objective, the proposed biochemical studies can lead to novel carbohydrate epitopes for future use. This program also allows us to design new approaches for the chemical synthesis of our target structures. NMR studies play an important role in determining the structure of our synthetic compounds. This program has been the prime source of support for our synthetic efforts which are focused to fulfill the following objectives: a) To obtain compounds that are important for specificity studies. b) To synthesize specific modified acceptors which can be used for a single enzyme activity. c) To acquire highly specific ligands for purification of our selected glycosyltransferases. d) Specificity studies will provide us with valuable information for designing modified analogs as inhibitors of these enzymes. As a long term objective, the combination of both inhibitors of critical enzyme for generating human tumor associated antigen and antigens as vaccine may prove beneficial in the treatment of cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA035329-14A1
Application #
6288325
Study Section
Pathobiochemistry Study Section (PBC)
Program Officer
Sathyamoorthy, Neeraja
Project Start
1984-07-01
Project End
2006-04-30
Budget Start
2001-05-01
Budget End
2002-04-30
Support Year
14
Fiscal Year
2001
Total Cost
$341,311
Indirect Cost
Name
Roswell Park Cancer Institute Corp
Department
Type
DUNS #
City
Buffalo
State
NY
Country
United States
Zip Code
14263
Xue, Jun; Laine, Roger A; Matta, Khushi L (2015) Enhancing MS(n) mass spectrometry strategy for carbohydrate analysis: A b2 ion spectral library. J Proteomics 112:224-49
Marathe, Dhananjay D; Buffone Jr, Alexander; Chandrasekaran, E V et al. (2010) Fluorinated per-acetylated GalNAc metabolically alters glycan structures on leukocyte PSGL-1 and reduces cell binding to selectins. Blood 115:1303-12
Marathe, Dhananjay D; Chandrasekaran, E V; Lau, Joseph T Y et al. (2008) Systems-level studies of glycosyltransferase gene expression and enzyme activity that are associated with the selectin binding function of human leukocytes. FASEB J 22:4154-67
Chandrasekaran, E V; Xue, Jun; Xia, Jie et al. (2008) Reversible sialylation: synthesis of cytidine 5'-monophospho-N-acetylneuraminic acid from cytidine 5'-monophosphate with alpha2,3-sialyl O-glycan-, glycolipid-, and macromolecule-based donors yields diverse sialylated products. Biochemistry 47:320-30
Chandrasekaran, E V; Xue, Jun; Piskorz, Conrad et al. (2007) Potential tumor markers for human gastric cancer: an elevation of glycan:sulfotransferases and a concomitant loss of alpha1,2-fucosyltransferase activities. J Cancer Res Clin Oncol 133:599-611
Beauharnois, Mark E; Neelamegham, Sriram; Matta, Khushi L (2006) Quantitative measurement of selectin-ligand interactions: assays to identify a sweet pill in a library of carbohydrates. Methods Mol Biol 347:343-58
Xia, Jie; Xue, Jun; Locke, Robert D et al. (2006) Synthesis of fluorinated mucin core 2 branched oligosaccharides with the potential of novel substrates and enzyme inhibitors for glycosyltransferases and sulfotransferases. J Org Chem 71:3696-706
Chandrasekaran, E V; Xue, Jun; Neelamegham, Sriram et al. (2006) The pattern of glycosyl- and sulfotransferase activities in cancer cell lines: a predictor of individual cancer-associated distinct carbohydrate structures for the structural identification of signature glycans. Carbohydr Res 341:983-94
Chandrasekaran, E V; Xue, Jun; Xia, Jie et al. (2005) Analysis of the specificity of sialyltransferases toward mucin core 2, globo, and related structures. identification of the sialylation sequence and the effects of sulfate, fucose, methyl, and fluoro substituents of the carbohydrate chain in the biosynthe Biochemistry 44:15619-35
Beauharnois, Mark E; Lindquist, Kevin C; Marathe, Dhananjay et al. (2005) Affinity and kinetics of sialyl Lewis-X and core-2 based oligosaccharides binding to L- and P-selectin. Biochemistry 44:9507-19

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