Enzymatic and chemical approaches for the synthesis of sialyl glycoconjugates.
In conclusion, either enzymatic or chemical approaches have their unique features and unavoidable disadvantages. Enzyme-catalyzed sialylations provide the desired sialo-glycosidic linkages in the two enzyme reactions (CMP-NeuAc synthetase and sialyltransferase) with exclusive stereoselectivity and high yield as long as the required sialyltransferase is available. High substrate specificity of the two enzymes is a limitation so that many unnatural glycoconjugates cannot be prepared enzymatically. As for chemical glycosylations of sialic acids, it is possible to introduce any modification in sialyl donor and acceptor, in addition to create special sugar linkages. Nevertheless, reducing the number of reaction steps (for preparing both donors and acceptors of glycosylation), and enhancing stereoselectivity, as well as reaction yield are still problems to be overcome.
Lin
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Institute of Biological Chemistry, Academia Sinica Nan-Kang, Taipei 11529, Taiwan. chunhung@gate.sinica.edu.tw
Lin
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CC
D000818:Animals; D001665:Binding Sites; D002240:Carbohydrate Sequence; D006017:Glycolipids / Q000096:biosynthesis* / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D015394:Molecular Structure; D000216:N-Acylneuraminate Cytidylyltransferase / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D012795:Sialoglycoproteins / Q000096:biosynthesis* / Q000138:chemical synthesis* / Q000737:chemistry; D012799:Sialyltransferases / Q000378:metabolism
D006017:Glycolipids; D012795:Sialoglycoproteins; C009255:sialoglycolipids; D012799:Sialyltransferases; D000216:N-Acylneuraminate Cytidylyltransferase; D009439:Neuraminidase