A spectrofluorimetric assay of calmodulin-dependent protein phosphatase using 4-methylumbelliferyl phosphate.
A continuous spectrofluorimetric assay of calmodulin-dependent phosphatase is described. The assay monitors the formation of a fluorescent 4-methylumbelliferone from the dephosphorylation of 4-methylumbelliferyl phosphate and detects as little as 1 pmol of 4-methylumbelliferone. The phosphatase shows a Km of 1.3 mM for the substrate and a Vmax of 100 nmol/mg/min.
D000818:Animals; D001921:Brain / Q000201:enzymology; D002148:Calmodulin-Binding Proteins / Q000032:analysis*; D002417:Cattle; D006868:Hydrolysis; D006923:Hymecromone / Q000031:analogs & derivatives; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D013997:Time Factors; D014468:Umbelliferones
D002148:Calmodulin-Binding Proteins; D014468:Umbelliferones; C005359:4-methylumbelliferyl phosphate; D006923:Hymecromone