Redox reactive reagents inhibiting and inactivating choline acetyltransferase

Abstract

3-Trimethylammoniomethyl catechol and N,N-dimethylepinephrine (catecholine) are redox reactive reagents which possess quarternary ammonium functional groups and the capacity to inhibit or inactivate choline binding macromolecules which mediate cholinergic neuronal function. Earlier studies reported the synthesis of 3-trimethylammoniomethyl catechol and demonstrated its redox-dependent covalent inactivation of the nicotinic acetylcholine receptor [Nickoloff et al., Biochemistry 24, 999–1007 (1985)]. Here we present the synthesis of catecholine and show that both 3-trimethylammoniomethyl catechol and catecholine are weak noncompetitive inhibitors (K i = 15 ± 6 and 25 ± 4 mM, respectively) of choline acetyltransferase (EC 2.3.1.6). Both agents irreversibly inactivate the enzyme.