Amylopectin: structure synthesis

Various alterations have been observed in amylopectin structure in the mutants of various starch synthase isoforms. SSI is involved in extending the shorter A and B chains to a length of 14 glucose units or less. ° SSII is involved in synthesis of B2 and B3 chains. " " SSIII is a major factor for synthesis of starch... 

These synthetic linear and branched molecules may be important as type polymers, particularly if the interconversion of amylose to amylopectin is intramolecular, in which case the initial molecular weight and molecular-weight distribution would be retained. There is the possibility that the in vitro synthesis may even result in a truly three-dimensional structure, as distinct from that of the natural component. 

Recently, the in vitro synthesis of amylopectin- or glycogen-like structures via a tandem reaction of phosphorylase and branching enzyme was reported [197-201]. 

This ehapter eonsiders the reeent view on moleeular structures of the amylose and amylopectin components in potato and how they are organized to form characteristie structures inside the stareh granules. The phosphorylation of starch, and the synthesis of its eomponents in normal and genetieally modified potatoes, is also discussed. 

Delrue, B., Fontaine, T., Routier, F., Decq. A., Wieruszeski, J.-M., Van Den Koomhuyse, N., Maddelein, M.-L., Fournet, B., and Ball, S. 1992. Waxy Chlamydomonas reinhardtii Monocellular algal mutants defective in amylose synthesis and granule-bound starch synthase activity accumulate a structurally modified amylopectin. J. BacterioL 174,3612-3620. 

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