2802
Amino acid residues at the N - and C - termini are essential for the folding of active human butyrylcholinesterase polypeptide .
 Chemical: Amino acid
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Amino acid