Amylopectin structure, enzymic analysis

In addition to its in vivo importance, R-enzyme is extremely useful for structural analysis. For example, the release of maltose and maltotriose from amylopectin jS-dextrin by R-enzyme provides good evidence of multiple branching, since the yield (12.8%) is near to that calculated (10.4%) for a tree-type structure having equal numbers of A- and B-chains. In addition, the simultaneous action of R-enzyme and 8-amylase can be used for the determination of CL (for details, see Ref. 144). 

Use of MALDI-TOF-MS allows relatively straightforward separation and identification of oligosaccharides with DPs up to 30. This feature makes it possible to identify products from enzymatic debranching of amylopectin. Richardsson et al. employed MALDI-TOF-MS and ESI-MS for enzyme-aided structure analysis of cationic potato amylopectin. " By MALDI-TOF-MS, identification of the oligosaccharides with DP 6-20 obtained from hydrolysis with pullulanase could be performed. Use of ESI-MS", on the other hand, provided detailed information on the chemical structure of oligosaccharides with DP <5. However, the lack of suitable standards prevented quantification by MALDI-TOF-MS and ESI-MS. 

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