23527
Tryptophan residue at active - site tunnel entrance of Trichoderma reesei cellobiohydrolase Cel7A is important to initiate degradation of crystalline cellulose .
 Chemical: Tryptophan
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: Tryptophan