The
monoclonal antibody 1H11(IgM)to Narcine timlei(Nt)acetylcholinesterase(AChE),and the AChEs from electric organs of Ntand Torpedo marmorata(Tm),flounder muscle,rat,bovine and
human brains,bovine and human redblood cells(RBC)were purified by using different affin-ity chromatography.Enzyme antigen immunoassayrevealed that 1H11 exhibited strong crossimmunoreactivites with AChEs of Tm,flounder mus-cle,fat,bovine and human brains,manifesting the highconservation of the
epitope recognized by 1H11 inevolution.No reacthity of 1H11 was observedn neitherWith human and
bovine RBC AChEs,nor with humanbutyrylcholinesterase(BChE).Enzyme activity ofTm AChEs could be markedly inhibited by 1H11,whereas AChEs from other sources remaincd intact.Itprobably indicates that the 1H11-directed epitope lo-cates near the active center formed in the threedimentional structure in Tm AChEs,and is outsidethe area in the AChE molecules of other specics.Edrophonium did not influence the antigen-antibodyreaction, indicating that 1H11 does not bind at theanionic site of the active center.N-glycosidase F treat-ment of AChE caused 1H11 to lose the binding capaci-ty with the enzyme. This implies that the major part of1N11-directed epitope is carbohydrate in nature. Thehigh specificity of 1H11 could be used in distinguishingthe brain AChE from RBC AChE or serum BChE.
More abstracts about the Polysaccharide antigenic determinants against vertebrate acetylcholinesterases and their inhibitory