Partial purification and characterization of cytidine 5'-diphosphate-diglyceride hydrolase from membranes of Escherichia coli.
Cytidine 5'-diphosphate (CDP)-diglyceride is hydrolyzed to phosphatidic acid and cytidine 5'-monophosphate by a specific membrane-bound enzyme in cell-free extracts of Escherichia coli. The hydrolase can be extracted from the particulate fraction with Triton X-100 and purified 1,000-fold in the presence of this detergent. Several nucleoside disphosphate diglycerides were synthesized to determine the substrate specificity of the hydrolase. CDP-diglyceride was hydrolyzed preferentially, although uridine 5'-diphosphate-diglyceride, guanosine 5'-diphosphate-diglyceride, and adenosine 5'-diphosphate (ADP)-diglyceride were also slowly hydrolyzed. Surprisingly, the purified enzyme did not catalyze detectable cleavage of deoxy-CDP (dCDP)-diglyceride. The liponucleotide pool of E. coli contains dCDP-diglyceride and CDP-diglyceride in approximately equal amounts (Raetz and Kennedy, 1973). Water-soluble nucleoside pyrophosphates, such as CDP-choline, nicotinamide adenine dinucleotide, or adenosine 5'-triphosphate are not attacked by this specific hydrolase. Hydrolysis of CDP-diglyceride is strongly inhibited by adenosine 5'-monophosphate and by ADP-diglyceride.
D002462:Cell Membrane / Q000201:enzymology; D002474:Cell-Free System; D011232:Chemical Precipitation; D003567:Cytidine Diphosphate Diglycerides / Q000378:metabolism; D003597:Cytosine Nucleotides / Q000096:biosynthesis; D006867:Hydrolases / Q000302:isolation & purification / Q000378:metabolism; D006868:Hydrolysis; D010712:Phosphatidic Acids / Q000096:biosynthesis; D011092:Polyethylene Glycols
D003567:Cytidine Diphosphate Diglycerides; D003597:Cytosine Nucleotides; D010712:Phosphatidic Acids; D011092:Polyethylene Glycols; D006867:Hydrolases