Acetylcholinesterase from oat Seedlings. I. Preliminary biochemical characterization of the enzyme

The activity of acetylcholinesterase (AChE) isolated from coleoptiles of etiolated oat seedlings is strongly inhibited by neostigmine and less so by eserine. The optimum of the enzyme activity occurs at pH 7.2 and a temperature of + 36 °C. The enzyme Michaelis constant is 280 μM. Choline within the range of concentration from 0.001 to 10 mM does not affect the enzyme activity. Calcium ions at 5 mM concentration cause inhibition, while magnesium and manganese ions do not affect the enzyme activity. AChE isolated from oat seedlings differs in a number of properties from AChE occurring in the tissues of other plants. This research was supported in part by grant CPBP 05.02.4.07.