3320
Removal of any single hydrophobic amino acid between the two charged amino acids in core peptide ( R , K ) resulted in lower binding .
 Chemical: amino acid; Chemical: amino acids
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; Chemical: amino acids