Transphosphatidylation capacity of phospholipase D from cabbage (Brassica oleracea L. var. capitata L.) leaves and Streptomyces chromofuscus

Abstract

The phospholipase D (PLD) was purified from leaves of cabbage (Brassica oleracea L. var. capitata L.). The molecular weight of the enzyme was estimated as 87 and 73.5-kDa on SDS-PAGE and gel filtration using Superdex 200 HR 10/30 column. The transphosphatidylation capacity of cabbage PLD was shown to be higher than that of Streptomyces chromofuscus PLD. Although cabbage PLD showed a single band, Streptomyces chromofuscus PLD gave several bands on nondenaturing and denaturing PAGE. These results indicated that the cabbage PLD was a monomer protein, while the Streptomyces chromofuscus PLD was hetero oligomer, having several types with different molecular weights. Furthermore, the cabbage PLD included the duplicated HxKxxxxD catalytic motifs in the molecule, but the Streptomyces chromofuscus PLD did not. Previously, YAMANE et al. reported that the transphosphatidylation capacity of Streptomyces sp. PLD was higher than that of Streptomyces chromofuscus. These results indicated that the high degree of the transphosphatidylation capacity of cabbage PLD was due to the existence of HxKxxxxD catalytic motifs.