DEVELOPMENTAL REGULATION OF MOUSE-BRAIN MONOMERIC ACETYLCHOLINESTERASE

Acetylcholinesterase (AChE) molecular forms were studied during mouse brain development. Mouse embryos expressed a monomeric (G(1)) and a te trameric (G(4)) AChE form. Our results indicate that G(4) AChE express ed at embryonic day (ED) 9 and ED15 could be purified by acridinium-Se pharose chromatography and shared similar biochemical and kinetic prop erties with the adult form. However, the G(1) form expressed at either embryonic stage did not bind to acridinium, was not inhibited by exce ss substrate, and possessed higher K-m and lower V-max values than the adult G(1) form. Two peripheral anionic binding site inhibitors, fasc iculin and propidium, had a significantly lower affinity for the monom eric form at ED9. Results are discussed in terms of the biological sig nificance of the embryonic G(1) form, and its resemblance to the AChE activity found, associated with the senile plaques present in the brai ns of Alzheimer's patients. (C) 1998 ISDN. Published by Elsevier Scien ce Ltd.