title: Differential inhibitory action of the fungal toxin orellanine on alkaline phosphatase isoenzymes.
abstract: The inhibitory action of orellanine (3,3',4,4'-tetrahydroxy-2,2'-dipyridyl-1,1'-dioxide), a fungal toxin of Cortinarius orellanus Fr. and C. orellanoides R. Hry., on alkaline phosphatase isoenzymes was studied. Orellanine specifically inhibited alkaline phosphatase activity in LLC-PK1 renal epithelial cell cultures and in the colon carcinoma cell line Caco-2 without affecting gamma-glutamyl transpeptidase activity. Kinetic studies revealed that orellanine acts on renal alkaline phosphatase as a noncompetitive inhibitor, whereas the intestinal and placental isoforms are inhibited competitively.
authors.affiliation: Institute of Microbiology, University of Innsbruck, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Ruedl
authors.forename: G
authors.initials: G
authors.lastname: Gstraunthaler
authors.forename: M
authors.initials: M
authors.lastname: Moser
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000494:pharmacology*; D000363:Agaricales; D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors*; D000818:Animals; D002417:Cattle; D002460:Cell Line; D005260:Female; D007422:Intestines / Q000201:enzymology; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D009183:Mycotoxins / Q000494:pharmacology; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011725:Pyridines / Q000494:pharmacology*; D005723:gamma-Glutamyltransferase / Q000037:antagonists & inhibitors
chemical_list: D007527:Isoenzymes; D009183:Mycotoxins; D011725:Pyridines; C030076:orellanine; D015082:2,2'-Dipyridyl; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase