Regulation of C4 photosynthesis: characterization of a protein factor mediating the activation and inactivation of NADP-malate dehydrogenase
| Autor: | Takeshi Kagawa, Marshall D. Hatch |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Biophysics
Dehydrogenase Biology Biochemistry Zea mays Dithiothreitol chemistry.chemical_compound Malate Dehydrogenase medicine Photosynthesis Molecular Biology Incubation C4 photosynthesis Plant Proteins chemistry.chemical_classification Hydrogen-Ion Concentration Plants Trypsin In vitro Chloroplast Enzyme Activation Molecular Weight Kinetics Enzyme chemistry NADP medicine.drug |
| Zdroj: | Archives of biochemistry and biophysics. 184(1) |
| ISSN: | 0003-9861 |
| Popis: | The leaf NADP-malate dehydrogenase of Zea mays is rapidly activated when leaves are illuminated and inactivated in the dark. The present studies show that inactive enzyme isolated from darkened leaves was activated by dithiothreitol and that the active enzyme was rapidly inactivated by oxygen in dithiothreitol-free solutions. Following the fractionation of leaf extracts, both the activation and inactivation of NADP-malate dehydrogenase in vitro were partially or totally dependent upon a separate small molecular weight protein factor. Activation and inactivation were largely or solely dependent upon this factor at pH 8.0 or less, but apparently only partially factor dependent at pH 9.0. The factor was heat stable, inactivated by incubation with trypsin, and had a molecular weight of about 10,000. It was mostly associated with the chloroplasts of mesophyll cells. |
| Databáze: | OpenAIRE |
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