Enzymes Related to Lactate Metabolism in Green Algae and Lower Land Plants
| Autor: | N. E. Tolbert, Peter J. Gruber, Sue Ellen Frederick |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
Pyruvate decarboxylation
Pyruvate dehydrogenase kinase Glycerol-3-phosphate dehydrogenase Biochemistry Physiology Genetics Dehydrogenase Plant Science Biology Oxoglutarate dehydrogenase complex Pyruvate dehydrogenase complex Branched-chain alpha-keto acid dehydrogenase complex Glycolate dehydrogenase |
| Zdroj: | Plant Physiology. 53:167-170 |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1104/pp.53.2.167 |
| Popis: | Cell-free extracts of Chlorella pyrenoidosa contained two enzymes capable of oxidizing d-lactate; these were glycolate dehydrogenase and NAD + -dependent d-lactate dehydrogenase. The two enzymes could be distinguished by differential centrifugation, glycolate dehydrogenase being largely particulate and NAD + -d-lactate dehydrogenase being soluble. The reduction of pyruvate by NADH proceeded more rapidly than the reverse reaction, and the apparent Michaelis constants for pyruvate and NADH were lower than for d-lactate and NAD + . These data indicated that under physiological conditions, the NAD + -linked d-lactate dehydrogenase probably functions to produce d-lactate from pyruvate. Lactate dehydrogenase activity dependent on NAD + was found in a number of other green algae and in the green tissues of a few lower land plants. When present in species which contain glycolate oxidase rather than glycolate dehydrogenase, the enzyme was specific for l-lactate rather than d-lactate. A cyclic system revolving around the production and utilization of d-lactate in some species and l-lactate in certain others is proposed. |
| Databáze: | OpenAIRE |
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