Abstract
In order to investigate the relationship between malate oxidation and subsequent cycle reactions, the effects of oxaloacetate, pyruvate, and thiamine pyrophosphate on malate oxidation in mung bean (Phaseolus aureus var. Jumbo) hypocotyl mitochondria were quantitatively examined. Malate oxidation was optimally stimulated by addition of pyruvate and thiamine pyrophosphate, whose addition lowered the apparent Km for malate from 5 mm to 0.1 mm. Intermediate analysis showed that the stimulatory effect was correlated with removal of oxaloacetate to citrate. Oxaloacetate added alone was shown not to be metabolized until addition of pyruvate and thiamine pyrophosphate; then oxaloacetate was converted in part to pyruvate and also to citrate. These results establish that malate oxidation in mung bean mitochondria is subject to control by oxaloacetate levels, which are primarily determined by the resultant of the activities of malate dehydrogenase, citrate synthase, and pyruvate dehydrogenase.
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Selected References
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- Avron M., Biale J. B. Metabolic Processes in Cytoplasmic Particles of the Avocado Fruit. III. The Operation of the Tricarboxylic Acid Cycle. Plant Physiol. 1957 Mar;32(2):100–105. doi: 10.1104/pp.32.2.100. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bowman E. J., Ikuma H. Regulation of Malate Oxidation in Isolated Mung Bean Mitochondria: II. Role of Adenylates. Plant Physiol. 1976 Sep;58(3):438–446. doi: 10.1104/pp.58.3.438. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bowman E. J., Ikuma H., Stein H. J. Citric Acid cycle activity in mitochondria isolated from mung bean hypocotyls. Plant Physiol. 1976 Sep;58(3):426–432. doi: 10.1104/pp.58.3.426. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brunton C. J., Palmer J. M. Pathways for the oxidation of malate and reduced pyridine nucleotide by wheat mitochondria. Eur J Biochem. 1973 Nov 1;39(1):283–291. doi: 10.1111/j.1432-1033.1973.tb03125.x. [DOI] [PubMed] [Google Scholar]
- Coleman J. O., Palmer J. M. The oxidation of malate by isolated plant mitochondria. Eur J Biochem. 1972 Apr 24;26(4):499–509. doi: 10.1111/j.1432-1033.1972.tb01792.x. [DOI] [PubMed] [Google Scholar]
- Day D. A., Wiskich J. T. The oxidation of malate and exogenous reduced nicotinamide adenine dinucleotide by isolated plant mitochondria. Plant Physiol. 1974 Jan;53(1):104–109. doi: 10.1104/pp.53.1.104. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Douce R., Bonner W. D., Jr Oxalacetate control of Krebs cycle oxidations in purified plant mitochondria. Biochem Biophys Res Commun. 1972 May 12;47(3):619–624. doi: 10.1016/0006-291x(72)90923-0. [DOI] [PubMed] [Google Scholar]
- Lance C., Hobson G. E., Young R. E., Biale J. B. Metabolic processes in cytoplasmic particles of the avocado fruit. IX. The oxidation of pyruvate and malate during the climacteric cycle. Plant Physiol. 1967 Apr;42(4):471–478. doi: 10.1104/pp.42.4.471. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lieberman M., Biale J. B. Cofactor Requirements for Oxidation of Alpha-Keto Acids by Sweet Potato Mitochondria. Plant Physiol. 1956 Nov;31(6):425–429. doi: 10.1104/pp.31.6.425. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Macrae A. R., Moorhouse R. The oxidation of malate by mitochondria isolated from cauliflower buds. Eur J Biochem. 1970 Sep;16(1):96–102. doi: 10.1111/j.1432-1033.1970.tb01058.x. [DOI] [PubMed] [Google Scholar]
- WALKER D. A., BEEVERS H. Some requirements for pyruvate oxidation by plant mitochondrial preparations. Biochem J. 1956 Jan;62(1):120–127. doi: 10.1042/bj0620120. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wiskich J. T., Bonner W. D. Preparation and Properties of Sweet Potato Mitochondria. Plant Physiol. 1963 Sep;38(5):594–604. doi: 10.1104/pp.38.5.594. [DOI] [PMC free article] [PubMed] [Google Scholar]
