Characterization of thiamine diphosphatase in rat small intestine.
The properties of thiamine diphosphatase (TDPase) and p-nitrophenylphosphatase (p-NPPase) in rat small intestine were investigated. TDPase activity, like p-NPPase activity, was high in the mucosa and in the proximal region. Both activities were high in the membrane-associated fractions of the duodenal mucosa. Furthermore, TDPase had the same properties as intestinal alkaline phosphatase (al-Pase). These results suggest that thiamine diphosphate (TDP) and p-nitrophenylphosphate (p-NPP) are hydrolyzed by a single enzyme, al-Pase, in the intestine.
D009597:4-Nitrophenylphosphatase / Q000378:metabolism; D000818:Animals; D002413:Cations, Divalent / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D011755:Pyrophosphatases / Q000378:metabolism*; D051381:Rats; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D013834:Thiamine Pyrophosphatase / Q000378:metabolism*
D002413:Cations, Divalent; D003486:Cyanides; D004791:Enzyme Inhibitors; D013439:Sulfhydryl Reagents; D004492:Edetic Acid; D009597:4-Nitrophenylphosphatase; D011755:Pyrophosphatases; D013834:Thiamine Pyrophosphatase