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Metabolic Processes in Cytoplasmic Particles of the Avocado Fruit
Author(s) -
Biale Jacob B.,
Young Roy E.,
Popper Catherine S.,
Appleman Wya E.
Publication year - 1957
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1957.tb07609.x
Subject(s) - citation , library science , history , environmental ethics , philosophy , computer science
Studies on the oxidation of Krebs’ cycle acids have been complicated, in some cases, by the inhibitory effects of one acid on the oxidation of another. The best known inhibition of this type is that of oxalacetate on the oxidation of succinate, which was first reported by Das (1) who used the Thunberg technique. Swingle et al. (2) confirmed the observation of Das with manometric methods. A thorough study of this inhibition was reported by Pardee and Potter (3) who observed it in rat liver homogenates and also to some extent in other animal tissues. They noted that the inhibition of succinate oxidation by oxalacetate was slowly relieved with time. Since their preparations were devoid of oxalacetate oxidase activity and since the concentration of total keto acids did not change throughout the process, they attributed the decrease in inhibition to the decarboxylation of oxalacetate to pyruvate, which was ineffective in causing inhibition. They also reported that adenosine triphosphate (ATP) reversed the inhibition while calcium ions enhanced it. Tyler (4) determined the effect of calcium, magnesium, and ATP on the succinoxidase system inhibited by oxalacetate. He found that the reversal of the inhibition was due mainly to magnesium and that ATP had an enhancing effect. In the presence of magnesium and ATP, the inhibition could be restored by the addition of calcium ions. This paper deals with some observations on the effects of oxalacetate on the oxidation of pyruvate and succinate by cytoplasmic particles (mitochondria) of the avocado fruit.