[Age changes in the allosteric properties of brain acetylcholinesterase].

d-tubocurarine and procaine have been shown to inhibit the acetylcholinesterase of rat brain homogenate by coupled and non-competitive mechanism respectively, which suggests binding to enzyme peripheral sites. Judging by values of Hill coefficient negative cooperativity in interactions between procaine sites is characteristic of all ages (n=0,8 and 0,53 for young and old rats) while such cooperativity for d-tubocurarine sites appears only at old age (n=1 and 0,6 for young and old animals). Values of Ki changed in opposite directions for each of the substances with aging.