2.4.1 Research on glycoproteins
Protein is the executor of life activities. During the study of
proteins, researchers found that proteins have many modifications. Among
these modifications, glycosylation is very common, and more than 50% of
the proteins found so far have glycosylation. Glycans are the sugar
components of glycoproteins, including sugar groups and various types of
branching structures, composed of various sugars, such as glucose,
galactose, mannose and rhamnose. Polysaccharides complete the
glycosylation modification of proteins by connecting oxygen on specific
amino acid residues to proteins. One way to study glycomics is to
analyze glycoproteins.
For glycoproteins, there are the following research methods:
- Glycosyl capture: Lectin can specifically recognize one sugar or a
variety of sugars to agglutinate glycoproteins, which can be used to
obtain crude glycoproteins[20].
- Fluorescent dyes: Fluorescent dyes are usually used in combination
with high-throughput two-dimensional gel electrophoresis for protein
discovery and identification[21].
- Liquid chromatography: Separation of glycoproteins by SEC-HILIC-CapLC
workflow and other techniques can be used to construct a
three-dimensional liquid phase glycan profile to obtain glycan
structure information[22].
- Mass spectrometry: Mass spectrometry is used to analyze the cleavage
rules of protein skeleton and sugar skeleton, which can be used for
glycosylation site analysis[23-25].
- Magnetic resonance: Through the change of atomic energy transition,
accurate calculation of composition, ring size and abnormal carbon
conformation can be used to accurately confirm the structure of sugar
chain[26].