Acetylcholinesterase enzyme reactor

Figure 4.15 shows a new type of enzyme reactor that has been devised for assays of choline and acetylcholine, using the enzymes acetylcholinesterase and choline... 

Paraoxon Waters UV—Vis 9 x 10"9—5 x 10 7 mol L 1 60 Use of immobilized acetylcholinesterase/zone stopping/in-line reactivation of the enzyme reactor [149]... 

C.G. Maria, T.M. Munoz, A. Townshend, Reactivation of an immobilized enzyme reactor for the determination of acetylcholinesterase inhibitors. Flow-injection determination of paraoxon, Anal. Chim. Acta 295 (1994) 287. 

Bartolini, M., Cavrini, V., and Andrisano, V. (2004) Monolithic micro-immobilised-enzyme reactor with human recombinant acetylcholinesterase for online inhibition studies./. Chromatogr. A, 1031,27-34. 

Numerous postcolumn enzymatic reactors have been designed for LCEC. Enzymes can be used to produce an electroactive compound from the analyte of interest or, alternatively, to generate an electroactive species that is proportional to analyte concentration. An example of the latter is the detection of acetylcholine [46]. In this case, acetylcholinesterase is used to convert acetylcholine to choline. The resulting choline is reacted with choline oxidase to produce hydrogen peroxide. The amount of hydrogen peroxide produced is directly proportional to the initial concentration of acetylcholine. Detection limits are in the 100 femto-mole range. 

In the following we attempt to describe the acetylcholinesterase/choline acetyltransferase enzyme system inside the neural synaptic cleft in a simple fashion see Figure 4.49. The complete neurocycle of the acetylcholine as a neurotransmitter is simulated in our model as a simple two-enzymes/two-compartments model. Each compartment is described as a constant-flow, constant-volume, isothermal, continuous stirred tank reactor (CSTR). The two compartments (I) and (II) are separated by a nonselective permeable membrane as shown in Figure 4.50. 

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