THREE ISOFORMS OF STARCH SYNTHASE AND TWO ISOFORMS OF BRANCHING ENZYME ARE PRESENT IN POTATO TUBER STARCH

摘要

Proteins were extracted from tuber starch of a normal and a transgenic potato line and separated by SDS gel electrophoresis. Granule-bound starch synthase I (GBSS I) was absent in the latter potato. In-gel digestion of specific protein bands, isolation of peptides by reversed phase chromatography and finally sequencing, showed that three isoforms of starch synthase and two isoforms of branching enzyme (SEE) were present in the starch. A cDNA fragment for SEE II was isolated. [References: 31]