Study on Degradation of Flavonols in Mutants of PoppyPapaver somniferumL.

We studied flavonol-degrading activity of cell-free extracts from petals of the flower color and structure mutants. The relationship between degradation of flavonols (kaempferol, quercetin, and myricetin) and biosynthesis of anthocyanins has been revealed. The white-flower mutant proved to have the highest flavonol-degrading activity toward all substrates, particularly quercetin. The mutations inhibiting synthesis of pelargonidin, an anthocyanin, provide for synthesis of various amounts of cyanidin in the petals. The flavonol-degrading activity considerably increases proportionally to the content of cyanidin. A similar relationship has been revealed in the mutants synthesizing both cyanidin and pelargonidin. The plants accumulating considerable amounts of pelargonidin in their petals have accordingly higher flavonol-degrading activity and predominantly hydrolyze kaempferol. The plants forming additional pods in their flower (pistillody) have higher flavonol-degrading activity as compared to the anther-in-petal and doubleness mutants     

Phospholipids of E. coli and activity of alkaline phosphatase]

The effects of liposomes prepared from the E. coli lipids on the activity of soluble alkaline phosphatase and on the complementation reaction between its subunits were studied. It was shown that the liposomes nonspecifically catalyze the dimerization of the enzyme subunits without changing the dimer activity. The effects of phospholipases A2 and C on the activity of membrane-bound alkaline phosphatase were studied. An interrelationship was found between the level of hydrolysis of membrane phosphatidyl glycerol (PG) by these enzymes and the changes in the activity of membrane-bound alkaline phosphatase. It was also shown that PG is less accessible to the effects of phospholipases in the cells with derepressed biosynthesis of alkaline phosphatase. It is assumed that the membrane PG interacts with the membrane-bound alkaline phosphatase during its translocation into the periplasm.