Differential interaction of the monoclonal antibody AE-1 with acetylcholinesterase oligomers and monomers from rabbit muscle microsomes, human brain and fetal bovine serum

The monoclonal antibody AE-I raised against acetylcholinesterase (AChE) from human erythrocytes (HE) is shown to react with active asymmetric and tetrameric AChE components from rabbit muscle microsomes (RMM), and with tetrameric forms from human brain (HE) or fetal bovine serum (FBS). However, it failed to bind to AChE monomers from RMM or HE. The results of Western blot revealed that the determinant for AE-I consisted of a conformational domain, not a primary sequence region, in the AChE subunit. The antibody recognized HE monomers and FBS dimers, but not FBS monomers. The formation of labile immunocomplexes between AE-1 and AChE subunits may explain the lack of interaction between the antibody and the monomers from non-erythrocyte sources. (C) 1997 Elsevier Science Ireland Ltd.