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Electrochemical Evaluation of the Kinetic Parameters of a Heterogeneous Enzyme Reaction in Presence of Metal Ions
Author(s) -
Stoytcheva Margarita
Publication year - 2002
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200207)14:13<923::aid-elan923>3.0.co;2-j
Subject(s) - acetylcholinesterase , chemistry , electrochemistry , metal ions in aqueous solution , metal , ion , enzyme , reactivity (psychology) , catalysis , kinetic energy , enzyme assay , inorganic chemistry , reaction rate , electrode , organic chemistry , medicine , alternative medicine , pathology , physics , quantum mechanics
Abstract The effect of the presence of metal ions on the catalytic activity of the immobilized acetylcholinesterase is investigated, applying an electrochemical approach. It was found that they act as reversible noncompetitive inhibitors with a decreasing in the range Cu 2+ , Cd 2+ , Fe 3+ and Mn 2+ reactivity, taking into account the pH influence. The kinetic parameters of the enzyme reaction: K $\rm{ {_{m}^{app}}}$ , I max and K I were determined under conditions of a kinetically controlled process and the activity of the fixed acetylcholinesterase is quantitatively evaluated. It was established that the enzyme immobilization modifies the type of inhibition. K m values for the native acetylcholinesterase in the absence and in the presence of metal ions are given.