Studies of reversible inhibition, irreversible inhibition, and activation of alkaline phosphatase by capillary electrophoresis.
Reversible inhibition, irreversible inhibition, and activation of calf intestinal alkaline phosphatase (EC 3.1.3.1) have been studied by capillary electrophoresis. The capillary electrophoretic enzyme-inhibitor assays were based on electrophoretic mixing of inhibitor and enzyme zones in a substrate-filled capillary. Enzyme inhibition was indicated by a decrease in product formation detected in the capillary by laser-induced fluorescence. Reversible enzyme inhibitors could be quantified by Michaelis-Menten treatment of the electrophoretic data. Reversible, competitive inhibition of alkaline phosphatase by sodium vanadate and sodium arsenate has been examined, and reversible, noncompetitive inhibition by theophylline has been studied. The K(i) values determined for these reversible inhibitors using capillary electrophoresis are within the range of values reported in the literature for the same enzyme-inhibitor combinations. Irreversible inhibition of alkaline phosphatase by EDTA at concentrations of 1.0mM and above has been observed. Activation of alkaline phosphatase has also been observed for EDTA at concentrations from 20 to 400 microM.
Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600, USA.
Angela R
AR
Whisnant
S Douglass
SD
Gilman
D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D001149:Arsenates / Q000494:pharmacology; D001667:Binding, Competitive; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology; D019075:Electrophoresis, Capillary / Q000379:methods*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007700:Kinetics; D013997:Time Factors; D014638:Vanadates / Q000494:pharmacology
D001149:Arsenates; D004791:Enzyme Inhibitors; D014638:Vanadates; C009277:sodium arsenate; D004492:Edetic Acid; D000469:Alkaline Phosphatase