Malate Synthetase in Higher Plants

Open Access
Publisher Website
Google Scholar
Abstract
The product of the malate synthetase reaction in crude castor bean preparations with acetate- 1-C14 (or acetyl-1-C14 CoA) and glyoxylate as substrates was shown to be malate-4-C 14. Malate synthetase was shown to be present in widely different amounts in a variety of plant materials. Although the enzyme is not confined to those tissues converting fats in sugars, the best sources are fatty seeds in which this change is occurring and which are known to contain isocitritase. During the 2nd and 3rd days of germination of the castor bean, the malate synthetase, which is present in the ripened seed, shows a striking increase in activity; it is maintained at this level for several days. The bulk of the malate synthetase activity of castor bean homogenates can be recovered with the mitochondria. The results reinforce earlier suggestions about the importance of malate synthetase and the glyoxylate cycle in the conversion of fats in carbohydrates.