[Isolation and properties of immobilized alkaline phosphatase from E. coli].
Preparations of alkaline phosphatase from E. coli, immobilized on Sepharose, with a specific activity of 40-60 U/g wet weight were obtained. The immobilized enzyme was stable up to 50 degrees C; at higher temperatures it was inactivated. At 70 degrees most of the activity was lost for 1 h. The substrate (AMP) stabilized the enzyme. In the temperature range from 30 to 40 degrees C activation of the enzyme was observed, especially pronounced in the presence of the substrate. The pH optimum of the immobilized enzyme activity (7.8-8.2) is shifted towards the acid region, as compared to the soluble enzyme (8.0-8.6). The kinetic parameters for inhibition by the reaction product were determined using the integral Michaelis-Menten equation. KmAMP was found to be higher in case of the immobilized enzyme as compared to the soluble one (5.02 X 10(-4) M and 1.85 X 10(-5) M, respectively), which seems to be associated with diffusion limitations.
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D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics
D004800:Enzymes, Immobilized; D000469:Alkaline Phosphatase
Poluchenie i izuchenie svoĭstv immobilizovannoĭ shchelochnoĭ fosfatazy E. coli.