Potato Tuber UDP-Glucose:Protein Transglucosylase Catalyzes Its Own Glucosylation
| Autor: | Juana S. Tandecarz, Fernando Ardila |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
chemistry.chemical_classification
Glycosylation Molecular mass Physiology fungi food and beverages Fast protein liquid chromatography Plant Science Biology carbohydrates (lipids) Residue (chemistry) Glycogen phosphorylase chemistry.chemical_compound Enzyme Biochemistry chemistry Genetics biology.protein Starch synthase Glucan Metabolism and Enzymology |
| Zdroj: | Plant physiology. 99(4) |
| ISSN: | 0032-0889 |
| Popis: | Potato (Solanum tuberosum L.) tuber UDP-glucose:protein transglucosylase (UPTG) (EC 2.4.1.112) is involved in the first of a two-step mechanism proposed for protein-bound alpha-glucan synthesis by catalyzing the covalent attachment of a single glucose residue to an acceptor protein. The resulting glucosylated 38-kilodalton polypeptide would then serve as a primer for enzymic glucan chain elongation during the second step. In the present report, we describe the fast protein liquid chromatography purification of UPTG from a membrane pellet of potato tuber. An apparently close association of UPTG, phosphorylase, and starch synthase was observed under native conditions during different purification steps. Enrichment of a 38-kilodalton polypeptide was found throughout enzyme purification. It is now shown that the purified UPTG, with an apparent molecular mass of 38 kilodaltons, undergoes self-glucosylation in a UDP-glucose- and Mn(2+)-dependent reaction. Therefore, it is concluded that UPTG is the enzyme and at the same time the priming protein required for the biogenesis of protein-bound alpha-glucan in potato tuber. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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