Epitopes of human brain acetylcholinesterase

Abstract

The main purpose of the present work was to identify B-cell epitopes on human brain acetylcholinesterase (AChE) by the synthetic peptide approach. Five hundred and seventy-four decapeptides comprising amino acids No. n to n+9 (where n denotes the residue number of the 583 amino acids in the primary structure of human brain AChE and is an integer in the range 1–574) were synthesized, using the multipin combinatorial chemical synthesis technique, and biotinylated. Epitopes of human brain AChE were detected by enzyme-linked immunosorbent assay (ELISA) and compared with the predicted epitopes of human AChE by ‘Goldkey’ software. Among 574 synthetic decapeptides, 47 decapeptides at 11 antigenic regions showed immunoreactivity with mouse anti-human brain AChE polyclonal antibodies. The minimum sequence of epitope was defined at every antigenic region explored. The locations and sequences of the former ten continuous epitopes at the 11 antigenic regions of the human brain AChE had been identified as follows: TPVLVWIY (112–119), RTVLVSMNY (143–151), LLDQRLALQW (173–182), RRATQLAH (246–253), VFRFSFVPV (294∼302), KDEGSYFLVY (332–341), RVYA (424–427), LMRY (476–479), KAPQWPPY (496–503), GLRAQACAFW (523–532). The rate of hits of the predicted epitopes from the software came out at 33%. In our work, the epitopes of human AChE have been mapped by purified polyclonal antibody at eleven distinct sites in the primary structure.