Derivation of the formyl-group oxygen of chlorophyll b from molecular oxygen in greening leaves of a higher plant (Zea mays)
| Autor: | W. Schäfer, Ingrid Katheder, Edmund Cmiel, Robert J. Porra, Hugo Scheer |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Chlorophyll b
Chlorophyll Oxygenase Chlorophyll a Stereochemistry Biophysics chemistry.chemical_element Photosynthesis Biosynthesis Biochemistry Oxygen Zea mays Mass Spectrometry Mixed Function Oxygenases chemistry.chemical_compound Greening Structural Biology Genetics Molecular Biology Molecular Structure Chemistry Chlorophyll A Isotope exchange Cell Biology Reductive extraction 18Oxygen Methyl group |
| Zdroj: | FEBS letters. 323(1-2) |
| ISSN: | 0014-5793 |
| Popis: | Using mass spectroscopy, we demonstrate as much as 93% enrichment of the 7-formyl group oxygen of chlorophyll b when dark-grown, etiolated maize leaves are greened under white light in the presence of 18O2. This suggests that a mono-oxygenase is involved in the oxidation of its methyl group precursor. The concomitant enrichment of about 75% of the 131-oxygen confirms the well-documented finding that this oxo group, in both chlorophyll a and b, also arises from O2. High 18O enrichment into the 7-formyl oxygen relative to the substrate 18O2 was achieved by optimization of the greening conditions in combination with a reductive extraction procedure. It indicates not only a single pathway for Chl b formyl group formation, but also unequivocally demonstrates that molecular oxygen is the sole precursor of the 7-formyl oxygen. |
| Databáze: | OpenAIRE |
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