Glycoproteomics

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Glycoproteomics is a branch of proteomics that identifies, catalogs, and characterizes proteins containing carbohydrates as a result of post-translational modifications. [1] Glycosylation is the most common post-translational modification of proteins, but continues to be the least studied on the proteome level. [2] Mass spectrometry (MS) is an analytical technique used to improve the study of these proteins on the proteome level. Glycosylation contributes to several concerted biological mechanisms essential to maintaining physiological function. The study of the glycosylation of proteins is important to understanding certain diseases, like cancer, because a connection between a change in glycosylation and these diseases has been discovered. To study this post-translational modification of proteins, advanced mass spectrometry techniques based on glycoproteomics have been developed to help in terms of therapeutic applications and the discovery of biomarkers. [3]

Contents

Mass spectrometry

Mass spectrometry is commonly used to identify the sugar moieties attached, but since there are many different glycan structures attached and different locations of glycosylation, this leads to challenges when attempting to sequence glycoproteins. [4] Using mass spectrometry, there are two methods for glycoprotein analysis. The first strategy is called "top-down" which uses intact glycoproteins for the mass spectrometry analysis without digesting and does not require an extensive sample preparation. The second and most common method for studying glycoproteins is the "bottom-up" strategy that initially cleaves the glycans from the glycoproteins using chemicals or enzymes. The glycans, which are carbohydrates, and proteins are purified, and individually analyzed. Based on the type of linkage that these glycans use to attach to proteins, different methods are used to separate the glycan from the protein. Using mass spectrometry, the glycan structures and sequences of the proteins can be determined, but where the glycans bind to on the protein is sometimes undetermined. The last approach involves glycoprotein digestion using the enzyme, endoprotease, so the digested glycoproteins can then be characterized by mass spectrometry techniques. Using this method, the glycosylated sites can be identified, so these approaches are used in conjunction when trying to identify glycoproteins. [5] As technology progresses, glycoprotein analyses have become more accurate using high-resolution mass spectrometry instrumentations. [2]

See also

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Proteomics is the large-scale study of proteins. Proteins are vital parts of living organisms, with many functions such as the formation of structural fibers of muscle tissue, enzymatic digestion of food, or synthesis and replication of DNA. In addition, other kinds of proteins include antibodies that protect an organism from infection, and hormones that send important signals throughout the body.

Glycomics is the comprehensive study of glycomes, including genetic, physiologic, pathologic, and other aspects. Glycomics "is the systematic study of all glycan structures of a given cell type or organism" and is a subset of glycobiology. The term glycomics is derived from the chemical prefix for sweetness or a sugar, "glyco-", and was formed to follow the omics naming convention established by genomics and proteomics.

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<span class="mw-page-title-main">Glycome</span>

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Anne Dell is an Australian biochemist specialising in the study of glycomics and the carbohydrate structures that modify proteins. Anne's work could be used to figure out how pathogens such as HIV are able to evade termination by the immune system which could be applied toward understanding how this occurs in fetuses. Her research has also led to the development of higher sensitivity mass spectroscopy techniques which have allowed for the better studying of the structure of carbohydrates. Anne also established GlycoTRIC at Imperial College London, a research center that allows for glycobiology to be better understood in biomedical applications. She is currently Professor of Carbohydrate Biochemistry and Head of the Department of Life Sciences at Imperial College London. Dell's other contributions to the study of Glycobiology are the additions she has made to the textbook "Essentials of Glycobiology" Dell was appointed Commander of the Order of the British Empire (CBE) in the 2009 Birthday Honours.

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References

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