... between human AChE and BChEThe T variants of human AChE and human BChE arecomposed of a catalytic domain of approximately 500residues, followed by small C-terminal t peptides of 40 and 41 residues, ... letters(A and B), whereas the small t peptides are designatedby lower case letters (a and b), so that the wild-typeAChE and BChE are Aa and Bb, and the chimeras areAb and Ba. Comparisons of wild-type ... differences betweenman and Maccaca mulatta, and the K variant of human BChE, which occurs with high frequency inEuropean and American populations, consists of thereplacement of A6 by a threonine...