title: Organic pyrophosphates as substrates for human alkaline phosphatases.
abstract: 1. Purified human liver and small-intestinal alkaline orthophosphatases release inorganic phosphate at appreciable rates from a variety of organic pyrophosphate substrates. 2. The pyrophosphatase action is inhibited by Mg(2+) ions at concentrations that activate the hydrolysis of orthophosphate substrates by these enzymes. 3. The results of mixed-substrate experiments, denaturation studies with heat or urea and starch-gel electrophoresis suggest that both orthophosphatase and pyrophosphatase activities are, in each preparation, properties of a single enzyme. 4. Intestinal phosphatase shows greater pyrophosphatase activity relative to orthophosphatase than the liver enzyme.
authors.affiliation: University Department of Clinical Chemistry, The Royal Infirmary, Edinburgh, 3.
authors.forename: R H
authors.initials: RH
authors.lastname: Eaton
authors.forename: D W
authors.initials: DW
authors.lastname: Moss