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Sorbitol-6-phosphate dehydrogenase from loquat fruit
1Okitsu Branch, Fruit Tree Research Station, Ministry of Agriculture, Forestry and Fisheries, Okitsu, Shizuoka, 424-02, Japan.
Plant Physiology
|April 1, 1979
Summary
Sorbitol-6-phosphate dehydrogenase was identified in loquat fruit. This enzyme catalyzes a key reaction in sugar metabolism, with optimal activity at high pH levels.
Area of Science:
- Biochemistry
- Plant Physiology
Background:
- Loquat fruit (Eriobotrya japonica) is a valuable horticultural crop.
- Understanding fruit metabolism is crucial for improving fruit quality and storage.
Purpose of the Study:
- To identify and characterize sorbitol-6-phosphate dehydrogenase in loquat fruit.
- To elucidate the enzymatic properties of this key metabolic enzyme.
Main Methods:
- Enzyme extraction from mature loquat fruit flesh.
- Purification of sorbitol-6-phosphate dehydrogenase.
- Enzymatic assays to determine substrate specificity and optimal pH.
Main Results:
- Sorbitol-6-phosphate dehydrogenase was successfully purified approximately 30-fold.
- The enzyme catalyzes the conversion of sorbitol-6-phosphate and NADP+ to glucose-6-phosphate and NADPH.
- Optimal pH for sorbitol-6-phosphate oxidation was 9.8, and for glucose-6-phosphate reduction was 9.1.
Conclusions:
- Sorbitol-6-phosphate dehydrogenase plays a role in loquat fruit metabolism.
- The enzyme exhibits alkaline optimal pH, suggesting specific cellular conditions for its activity.
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