title: The regulation of myo-inositol-1-phosphate-synthase activity from Neurospora crassa by pyrophosphate and some cations.
abstract: The effect of several cations on the inhibition by PPi of the enzyme myo-inositol-1-phosphate synthase (1L-myo-inositol-1-phosphate lyase (isomerizing) EC 5.5.1.4) from Neurospora crassa was studied. The study wastol biosynthesis can occur in the presence of an intracellular PPi concentration which exceeds the Ki for the enzyme by 350-fold. The inhibition of enzyme activity by PPi,at pH 7.7, was reversed, in decreasing order of effectiveness, by Mn-2, Fe-3
mesh_terms: D000641:Ammonia / Q000494:pharmacology; D002238:Carbohydrate Epimerases / Q000378:metabolism*; D002413:Cations, Divalent; D011756:Diphosphates / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005958:Glucosephosphates / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000494:pharmacology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D007296:Myo-Inositol-1-Phosphate Synthase / Q000378:metabolism*; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000187:drug effects / Q000201:enzymology*; D011188:Potassium / Q000494:pharmacology
chemical_list: D002413:Cations, Divalent; D011756:Diphosphates; D005958:Glucosephosphates; D000641:Ammonia; D007501:Iron; D002238:Carbohydrate Epimerases; D007296:Myo-Inositol-1-Phosphate Synthase; D008274:Magnesium; D011188:Potassium