Reducing-end-labeled maltodextrins

In these a-amylase reactions, glucose is not the primary product. Glucose is formed as a secondary product in the hydrolysis of maltotriose, maltotetraose and branched dextrins. Using 14C-reducing end labeled maltodextrins, G3 to G8, Robyt and French19 showed that porcine pancreatic a-amylase has different specificities for hydrolyzing the different linkages of the maltodextrins. The different frequencies for... 

Figure 3. Synthesis of reducing-end labeled maltodextrins by reaction of B. macerans cyclodextrin glucanosyl transferase with cyclomaltohexaose and various kinds of acceptors. Symbols are the same as in Figure 2.

Maltodextrins and isomaltodextrins specifically labeled in (a) the reducing-end glucopyranosyl unit, (b) the nonreducing-end glucopyranosyl unit, (c) a specific number of labeled glucopyranosyl units at one or the other end or both of the chain ends, and (d) all of the glucopyranosyl units uniformly labeled, find uses in the study of the function of the dextrins and especially in the study of the mechanisms of enzymes that interact with the dextrins and related substrates. Branched maltodextrins and cyclodextrins can also be specifically labeled. All of the methods that will be discussed involve the use of specific enzymes that are commercially available or can be readily prepared in the laboratory. 

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