title: Anandamide amidohydrolase activity, released in the medium by Tetrahymena pyriformis. Identification and partial characterization.
abstract: Anandamide, an endogenous cannabinoid receptor ligand, was rapidly metabolized by Tetrahymena pyriformis in vivo. Metabolic products were mainly phospholipids as well as neutral lipids, including small amounts of free arachidonic acid. Anandamide amidohydrolase activity was detected in the culture medium by the release of [3H]arachidonic acid from [3H]anandamide, in a time- and concentration-dependent manner. Kinetic experiments demonstrated that the released enzyme had an apparent K(m) of 3.7 microM and V(max) 278 pmol/min/mg protein. Amidohydrolase activity was maximal at pH 9-10, was abolished by phenylmethylsulfonyl fluoride and was Ca(2+)- and Mg(2+)-independent. Thus, T. pyriformis is capable of hydrolyzing anandamide in vivo and releasing amidohydrolase activity.
authors.affiliation: Department of Chemistry (Biochemistry), University of Athens, Panepistimioupolis, 15771, Athens, Greece.
authors.forename: V
authors.initials: V
authors.lastname: Karava
authors.forename: L
authors.initials: L
authors.lastname: Fasia
authors.forename: A
authors.initials: A
authors.lastname: Siafaka-Kapadai
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001095:Arachidonic Acids / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D003470:Culture Media; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D063388:Endocannabinoids; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D050356:Lipid Metabolism; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D053284:Polyunsaturated Alkamides; D013696:Temperature; D013769:Tetrahymena pyriformis / Q000201:enzymology*; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D016718:Arachidonic Acid; D001095:Arachidonic Acids; D002118:Calcium; D003470:Culture Media; D004228:Dithionitrobenzoic Acid; D004229:Dithiothreitol; D004492:Edetic Acid; D004533:Egtazic Acid; D063388:Endocannabinoids; D004791:Enzyme Inhibitors; D008274:Magnesium; D010664:Phenylmethylsulfonyl Fluoride; D010743:Phospholipids; D053284:Polyunsaturated Alkamides; D000099252:Fatty Acid Amide Hydrolases; C078814:anandamide