A reversible phospholipase active on phosphatidylcholine (PC) and phosphatidylethanolamine. Lysophosphatidylcholine and egg sphingomyelin are hydrolyzed about 50 times and 100 times more slowly than PC, respectively. During the transphosphatidylation reaction straight-chain hydroxy compounds, such as triethyleneglycol and triethyleneglycol monomethyl ether, were phosphatidylated in good yield, as were monosaccharides. Disaccharides and sugar alcohol reacted slowly, while N-acetyl-D-galactosamine, D-galactosamine and D-galacturonic acid were not phosphatidylated. a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1,2-diacyl-sn-glycero-3-phosphate + choline + H(+) Inhibited by mercaptoethanol and dithiothreitol. Optimum pH is 5.5 in both directions. Optimum temperature is 60 degrees Celsius in both directions. Probably has at least 1 disulfide bond. May be useful in the production of emulsifiers. Belongs to the phospholipase D family.