title: Enzyme activation for activator and enzyme activity measurement.
abstract: A new sensing principle of enzyme activation is demonstrated for the determination of glycogen phosphorylase b and its allosteric effector AMP. As the indicator of the phosphorylase catalysed glycogen phosphorolysis, glucose-1-phosphate formation has been detected with an enzyme sequence comprising coentrapped alkaline phosphatase, mutarotase and glucose oxidase on a hydrogen peroxide indicating electrode. The optimized three-enzyme sensor was useful for the determination of 0.005-0.2 U.ml-1 glycogen phosphorylase a and b. A biosensor for AMP and inorganic phosphate has been developed by coupling glycogen entrapped phosphorylases to the three-enzyme indicator membrane. The measurement of AMP is based on the modulation of the phosphorylase b catalysed glycogen phosphorylating activity. The proposed sensor responds to AMP between 5 and 150 microM. The calibration graph of the reagentless phosphate sensor is linear between 0.05 and 1 mM.
authors.affiliation: Max Delbrück Centre of Molecular Medicine, Department of Biosensors, Berlin, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Wollenberger
authors.forename: F W
authors.initials: FW
authors.lastname: Scheller
mesh_terms: D000249:Adenosine Monophosphate / Q000494:pharmacology; D000494:Allosteric Regulation; D000818:Animals; D015374:Biosensing Techniques; D004789:Enzyme Activation; D010710:Phosphates / Q000032:analysis; D006005:Phosphorylases / Q000378:metabolism*; D011817:Rabbits
chemical_list: D010710:Phosphates; D000249:Adenosine Monophosphate; D006005:Phosphorylases