Purification, characterization, and subcellular localization of an acid phosphatase from black mustard cell-suspension cultures: Comparison with phosphoenolpyruvate phosphatase
| Autor: | Stephen M. G. Duff, Daniel D. Lefebvre, William C. Plaxton |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Macromolecular Substances
Acid Phosphatase Phosphatase Biophysics Brassica Biology Peptide Mapping Biochemistry Chromatography Affinity Cell wall Molecular Biology Cells Cultured Chromatography High Pressure Liquid chemistry.chemical_classification Molecular mass Protoplasts Acid phosphatase Subcellular localization Isoenzymes Molecular Weight Kinetics Phosphoenolpyruvate phosphatase Enzyme chemistry Vacuoles biology.protein Phosphorylation Electrophoresis Polyacrylamide Gel Subcellular Fractions |
| Zdroj: | Archives of Biochemistry and Biophysics. 286:226-232 |
| ISSN: | 0003-9861 |
| DOI: | 10.1016/0003-9861(91)90033-f |
| Popis: | An acid phosphatase from Brassica nigra (black mustard) leaf petiole cell-suspension cultures has been purified 1633-fold to a final specific activity of 1225 (μmol orthophosphate produced/min)/mg protein and near homogeneity. The native protein was a glycosylated monomer having a molecular mass of 60 kDa and a p I of 4.5. The enzyme displayed a broad pH optimum of about pH 5.6 and was heat stable. The final preparation hydrolyzed a wide variety of phosphate esters. The highest specificity constants were obtained with 3-phosphoglycerate, 2,3-diphosphoglycerate, PP i and phospho enol pyruvate (PEP). The enzyme was activated 1.4-fold by 4 m m Mg 2+ or Mn 2+ , but was strongly inhibited by Mo, P i , F, and several phosphorylated compounds. Subcellular localization experiments revealed that this nonspecific acid phosphatase is probably a secreted enzyme, localized in the cell wall. By contrast, B. nigra PEP phosphatase appeared to be localized in the cell vacuole. Peptide mapping via CNBr fragmentation was employed to investigate the structural relatedness of the two phosphatases. Their respective CNBr cleavage patterns were dissimilar, suggesting that B. nigra acid and PEP phosphatases are distinct polypeptides. Putative metabolic functions of these two phosphatases are discussed in relation to the biochemical adaptations of B. nigra cell-suspension cultures to nutritional phosphate deprivation. |
| Databáze: | OpenAIRE |
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