- Email: [email protected]
Oligosaccharide microarrays for glycomics
Update
TRENDS in Biotechnology
Therefore, a more precise analytical method is needed to determine weak interactions. This is emphasised from a biological viewpoint because cell – cell recognition events, supposedly mediated by lectins, would be expected to be more successful if weak rather than strong to discriminate subtle differences in cell-surface glycans. A weaker interaction (thus fast dissociation) would be advantageous for repeated association and dissociation processes. In this context, frontal affinity chromatography (FAC), which has been recently drastically improved in various contexts [10,11], exerts its high potential in particular for analysis of weak interactions. However, FAC is basically liquid chromatography and the merits of using biochips (e.g., in searching for unidentified lectins) cannot be taken advantage of by this method. However, methods that fulfil the requirements for extremely high sensitivity might be mass spectrometry or fluorescence techniques. The development of a non-washing-type affinity sensor should answer the question of why biological systems use lectin – carbohydrate interactions that are, in general, weak and thus pioneer new fields of postgenome sciences.
Vol.21 No.4 April 2003
143
2 Varki, A., et al. eds (1999) Essentials of Glycobiology Cold Spring Harbor Laboratory 3 Wang, D. et al. (2002) Carbohydrate microarrays for the recognition of cross-reactive molecular markers of microbes and host cells. Nat. Biotechnol. 20, 234– 235 4 Banin, E. et al. (2002) A Novel Linear Codew Nomenclature for Complex Carbohydrates. Trends Glycosci. Glycotechnol. 14, 127 – 137 5 Fukui, S. et al. (2002) Oligosaccharide microarrays for high-throughput detection and specificity assignments of carbohydrate-protein interactions. Nat. Biotechnol. 20, 1011 – 1017 6 Feizi, T. et al. (1994) Neoglycolipids: probes of oligosaccharide structure, antigenicity and function. Methods Enzymol 230, 484 – 519 7 Feizi, T. (2000) Progress in deciphering the information content of the ‘glycome’ – a crescendo in the closing years of the millennium. Glycoconjugate J. 17, 553– 565 8 Chai, W. et al. (1999) Core-branching pattern and sequence analysis of mannitol-terminating oligosaccharides by neoglycolipid technology. Anal. Biochem. 270, 314 – 322 9 Hirabayashi, J. et al. (2002) Oligosaccharide specificity of galectins: a search by frontal affinity chromatography. Biochim. Biophys. Acta. 1572, 232– 254 10 Chan, N.W. et al. (2002) Frontal affinity chromatography for the screening of mixtures. Comb. Chem. High Throughput Screen. 5, 395– 406 11 Hirabayashi, J. and Kasai, K. (2002) Separation technologies for glycomics. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 771, 67 – 87
References 1 Apweiler, R. et al. (1999) On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database. Biochim. Biophys. Acta 1473, 4 – 8
0167-7799/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0167-7799(03)00002-7
| Research Focus Response
Oligosaccharide microarrays for glycomics Response from Ten Feizi
Ten Feizi Glycosciences Laboratory, Imperial College London, Northwick Park Hospital Campus, Harrow, Middlesex HA1 3UJ, UK
As reported by Hirabayashi in the above article, my colleagues and I have described microarrays of oligosaccharides linked to lipids (neoglycolipids), encompassing naturally occurring sequences on glycoproteins, glycolipids and proteoglycans. We also demonstrated selective binding by several proteins, including antibodies, the selectins, a cytokine and a chemokine [1]. I wish to comment on three of the points raised in the article. The first is the repertoire of structurally defined oligosaccharides that we described in our paper; the second is that two of our array systems consisted of fractions containing mixtures of glycans; the third point is the importance of being able to detect weak carbohydrate – protein interactions. Our paper is a proof of concept study; the selection of structurally defined oligosaccharides was, of course, not intended to be exhaustive at this stage but positive and negative controls were included for the several Corresponding author: Ten Feizi ([email protected]). http://tibtec.trends.com
carbohydrate-binding proteins. Arrays of partially fractionated oligosaccharides from natural sources were illustrated to show that specific binding signals are elicited and that ligand-positive spots are amenable to powerful deconvolution procedures that include sequence determination by mass spectrometry. Our oligosaccharide probes are designed by the neoglycolipid technology, their special feature being their clustered presentation on matrices used for immobilization, which we agree is important for detecting weak carbohydrate – protein interactions.
References 1 Fukui, S. et al. (2002) Oligosaccharide microarrays for high-throughput detection and specificity assignments of carbohydrate – protein interactions. Nature Biotechnol. 20, 1011 – 1017
0167-7799/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0167-7799(03)00055-6
TRENDS in Biotechnology
Therefore, a more precise analytical method is needed to determine weak interactions. This is emphasised from a biological viewpoint because cell – cell recognition events, supposedly mediated by lectins, would be expected to be more successful if weak rather than strong to discriminate subtle differences in cell-surface glycans. A weaker interaction (thus fast dissociation) would be advantageous for repeated association and dissociation processes. In this context, frontal affinity chromatography (FAC), which has been recently drastically improved in various contexts [10,11], exerts its high potential in particular for analysis of weak interactions. However, FAC is basically liquid chromatography and the merits of using biochips (e.g., in searching for unidentified lectins) cannot be taken advantage of by this method. However, methods that fulfil the requirements for extremely high sensitivity might be mass spectrometry or fluorescence techniques. The development of a non-washing-type affinity sensor should answer the question of why biological systems use lectin – carbohydrate interactions that are, in general, weak and thus pioneer new fields of postgenome sciences.
Vol.21 No.4 April 2003
143
2 Varki, A., et al. eds (1999) Essentials of Glycobiology Cold Spring Harbor Laboratory 3 Wang, D. et al. (2002) Carbohydrate microarrays for the recognition of cross-reactive molecular markers of microbes and host cells. Nat. Biotechnol. 20, 234– 235 4 Banin, E. et al. (2002) A Novel Linear Codew Nomenclature for Complex Carbohydrates. Trends Glycosci. Glycotechnol. 14, 127 – 137 5 Fukui, S. et al. (2002) Oligosaccharide microarrays for high-throughput detection and specificity assignments of carbohydrate-protein interactions. Nat. Biotechnol. 20, 1011 – 1017 6 Feizi, T. et al. (1994) Neoglycolipids: probes of oligosaccharide structure, antigenicity and function. Methods Enzymol 230, 484 – 519 7 Feizi, T. (2000) Progress in deciphering the information content of the ‘glycome’ – a crescendo in the closing years of the millennium. Glycoconjugate J. 17, 553– 565 8 Chai, W. et al. (1999) Core-branching pattern and sequence analysis of mannitol-terminating oligosaccharides by neoglycolipid technology. Anal. Biochem. 270, 314 – 322 9 Hirabayashi, J. et al. (2002) Oligosaccharide specificity of galectins: a search by frontal affinity chromatography. Biochim. Biophys. Acta. 1572, 232– 254 10 Chan, N.W. et al. (2002) Frontal affinity chromatography for the screening of mixtures. Comb. Chem. High Throughput Screen. 5, 395– 406 11 Hirabayashi, J. and Kasai, K. (2002) Separation technologies for glycomics. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 771, 67 – 87
References 1 Apweiler, R. et al. (1999) On the frequency of protein glycosylation, as deduced from analysis of the SWISS-PROT database. Biochim. Biophys. Acta 1473, 4 – 8
0167-7799/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0167-7799(03)00002-7
| Research Focus Response
Oligosaccharide microarrays for glycomics Response from Ten Feizi
Ten Feizi Glycosciences Laboratory, Imperial College London, Northwick Park Hospital Campus, Harrow, Middlesex HA1 3UJ, UK
As reported by Hirabayashi in the above article, my colleagues and I have described microarrays of oligosaccharides linked to lipids (neoglycolipids), encompassing naturally occurring sequences on glycoproteins, glycolipids and proteoglycans. We also demonstrated selective binding by several proteins, including antibodies, the selectins, a cytokine and a chemokine [1]. I wish to comment on three of the points raised in the article. The first is the repertoire of structurally defined oligosaccharides that we described in our paper; the second is that two of our array systems consisted of fractions containing mixtures of glycans; the third point is the importance of being able to detect weak carbohydrate – protein interactions. Our paper is a proof of concept study; the selection of structurally defined oligosaccharides was, of course, not intended to be exhaustive at this stage but positive and negative controls were included for the several Corresponding author: Ten Feizi ([email protected]). http://tibtec.trends.com
carbohydrate-binding proteins. Arrays of partially fractionated oligosaccharides from natural sources were illustrated to show that specific binding signals are elicited and that ligand-positive spots are amenable to powerful deconvolution procedures that include sequence determination by mass spectrometry. Our oligosaccharide probes are designed by the neoglycolipid technology, their special feature being their clustered presentation on matrices used for immobilization, which we agree is important for detecting weak carbohydrate – protein interactions.
References 1 Fukui, S. et al. (2002) Oligosaccharide microarrays for high-throughput detection and specificity assignments of carbohydrate – protein interactions. Nature Biotechnol. 20, 1011 – 1017
0167-7799/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0167-7799(03)00055-6