Carbohydrates sulfhydryl-reactive

This same type of modification strategy also can be used to create highly reactive groups from functionalities of rather low reactivity. For instance, carbohydrate chains on glycoproteins can be modified with sodium periodate to transform their rather unreactive hydroxyl groups into highly reactive aldehydes. Similarly, cystine or disulfide residues in proteins can be selectively reduced to form active sulfhydryls, or 5 -phosphate groups of DNA can be transformed to yield modifiable amines. 

At high pH (10), Traut s reagent also is reactive with aliphatic and aromatic hydroxyl groups, although the rate of reaction with these groups is only about 0.01 that of primary amines. In the absence of amines, however, carbohydrates such as agarose or cellulose membranes can be modified to contain sulfhydryl residues (Alagon and... 

The following reagents and techniques can be used to transform directly car-boxylates or sulfhydryl groups into reactive amine functional groups. In addition, sugars, polysaccharides, or carbohydrate-containing macromolecules may be modified to contain amines after mild periodate activation to form aldehyde groups. 

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