Inhibition of Cholinesterase by Dialkylcarbamates
Abstract The pI50 index and separation coefficients of chosen 3-N,N-diethylaminophenyl-N′,N′-dialkylcarbamates were determined. Index pI50 (pI50 = negative logarithm of molar concentration of inhibitor inhibiting the enzyme activity by 50%) describes the effectiveness of the inhibitor. The rate of ability of the inhibitor to pass the blood-brain barrier is usually described by the separation coefficient in a system n-octanol/water (Kow). Obtained results were compared with pI50 and Kow of Exelon®, the commercially used drug against the Alzheimer’s disease.
Kinetics of the total hydrolysis of acetyl-β-methylcholine by acetylcholinesterase
Mechanism and kinetics of in vitro hydrolysis of acetyl-β-methylcholine by acetylcholinesterase from electric eel in a mixed batch reactor at 25 and 37°C, pH 8, ionic strength 0.11 M and catalytic activity of the enzyme preparat of 3.5 U mL−1 were studied. The optimal kinetic parameters were determined.
Kinetics of Total Enzymatic Hydrolysis of Acetylcholine and Acetylthiocholine
Kinetics and the mechanism of total in vitro hydrolyses (i.e. up to the exhaustion of substrate) of acetylcholine and acetylthiocholine by acetylcholinesterase and butyrylcholinesterase were studied in vitro in a batch reactor at 25 °C, pH 8 and ionic strength of 0.11 ᴍ. Every hydrolysis was monitored by 2 - 3 independent analytical methods. All studied types of enzymatic hydrolyses fulfilled the Michaelis - Menten reaction scheme with the irreversible second step. A table of obtained average values of rate constants and estimations of initial molar enzyme concentrations, and discussion of the results are presented.