Phospholipase D-catalyzed hydrolysis of phosphatidylcholine occurs with P-O bond cleavage.
Mammalian phospholipase D has been implicated in signal-transduction mechanisms, most recently in association with stimuli that enhance phosphatidylcholine (PC) turnover. It was previously unknown whether hydrolysis of PC by phospholipase D proceeds via P-O or C-O bond cleavage. Commercially available phospholipase D isolated from Streptomyces chromofuscus was used to hydrolyse distearoyl phosphatidylcholine (PC) in a detergent-containing buffer consisting of 90% 18O-water. The product of hydrolysis, phosphatidic acid (PA), was purified by thin-layer chromatography and analyzed using californium-252 plasma desorption mass spectrometry. An increase of two mass units was observed, compared to a distearoyl PA control, consistent with a reaction mechanism involving cleavage of the P-O bond.
Holbrook
P G
PG
Laboratory of Bioorganic Chemistry, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
Pannell
L K
LK
Daly
J W
JW
D006868:Hydrolysis; D007553:Isotope Labeling / Q000379:methods; D013058:Mass Spectrometry; D010100:Oxygen; D010103:Oxygen Isotopes; D010712:Phosphatidic Acids / Q000302:isolation & purification; D010713:Phosphatidylcholines / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D010758:Phosphorus; D013302:Streptomyces / Q000201:enzymology
D010103:Oxygen Isotopes; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010758:Phosphorus; C010942:1,2-distearoyllecithin; D010739:Phospholipase D; D010100:Oxygen