The action of cabbage-leaf phospholipase D upon lysolecithin.

1. The action of the water-soluble phospholipase D from Savoy cabbage leaves upon an aqueous solution of lysolecithin has been studied. 2. Optimum conditions required the presence of Ca(2+) ions and pH5.8. 3. Equivalence was found between the amounts of lysolecithin hydrolysed and free choline released. The reaction was not accompanied by deacylation. 4. As the enzymic degradation proceeded, an opalescence developed, owing to the insolubility of the reaction product in the presence of Ca(2+) ions. 5. Evidence has been obtained indicating the heterogeneity of this reaction product.