Methods in Glycomics Research

Posted by beauty33 on March 19th, 2019

Glycomics is a new field of research after genomics and proteomics. Its results are directly related to the elucidation of gene function and cellular function. The specific content includes the study of the relationship and interaction between sugar and sugar, between sugar and protein, and between sugar and nucleic acid. The main object of research is polysaccharides.

Since the initiation of glycomics in the early 21st century, many achievements have been made in the study of glycomics, especially in the discovery of glyco-gene Microarray Assay and the elucidation of new structure of glycan. In the development of glycomics, the advancement of analytical techniques has always been a direct driving force. It is the advance and wide application of modern instrumental analysis technology that finally leads to the overall prosperity of glycomics research and injects new vitality into the development of many subjects including glycomics. Here to introduce two methods in glycomics research:

Glyco-Catch

As a new affinity technology, glyco-catch has been used in glycopeptides analysis in the study of glycosylation. By combining with proteome database, this method can systematically identify possible glycoproteins and glycosylation site. The specific strategy is summarized as follows:

1) Lectin affinity chromatography (used for glycoproteins separation);

2) Protein digestion;

3) Lectin affinity chromatography (used for glycopeptides separation);

4) HPLC purification of glycopeptides: the glycopeptides obtained by the above steps is usually a mixture, which should be further purified by two-dimensional HPLC;

5) Sequence analysis, mass spectrometry and determination of ionization constant;

6) Database search and polysaccharide structure analysis to obtain relevant genetic and glycosylation information. Then, different lectin columns were used for the second and third cycles, and other types of glycopeptides were collected to conduct a comprehensive study of the glycomics of a given cell;

Carbohydrate Microarray

   Unlike genomics and proteomics, there is currently no mature high-throughput tool for glycomics research. Recently, scientists have introduced microarray technology into glycomics, which can be widely used in glycosyl-binding protein analysis to systematically identify and characterize the whole proteoglycan structure produced by individual organisms. With the development of glycomics, various kinds of carbohydrate chips have been invented based on the principle of chip. This method has been widely used since the study on carbohydrate chips was first reported. Due to its characteristics of large amount of information and automation, such as gene chip for gene research and protein chip for proteome research, carbohydrate chip will also play an important role in the study of glycomics.

Carbohydrate microarray technology is a kind of biological chip, which is the polysaccharides with amino covalently connected to the glass chip covered by a chemically active surface. One chip can arrange more than 200 kinds of different carbohydrates structure, which covers almost all the main types of terminal carbohydrates. Because glycoproteins usually identify only the last few end glycoside residues in the glycan, it is speculated that there are about 500 end sequences that naturally exist. This technique has been successfully used for the screening and characterization of glycoprotein (lectin), but the number of carbohydrate available for microarrays is still very limited, limiting its widespread use.

   In the hope of more convenient technology to determine the glycan structure, how to use the existing technology to carry out glycomics research should be more important for glycobiologist to consider. In the aspect of glycan enrichment, although lectin has specific binding effect on polysaccharides, not all polysaccharides have lectin with specific binding. Mass spectrometer is the most important tool for structure determination, but the high price limits its wider application. However, the emergence and application of carbohydrate chip technology has played a significant role in promoting the study of the structure and function of polysaccharides, and it will be more widely used in the study of glycomics.