15286
Mass spectral analysis of the active site peptide from inhibited BChE showed that the inhibitor added a mass of 108 Da to the active site serine on peptide FGES198AGAAS .
 Chemical: serine
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: serine