7104
Crystal structures of the enzyme - inhibitor complexes showed that the nitrile warhead inhibits 3CL ( pro ) by forming a covalent bond with the catalytic Cys145 residue , while the AVLQ peptide forms a number of favourable interactions with the S1 - S4 substrate - binding pockets .
 Chemical: nitrile; Chemical: Cys145
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: nitrile; Chemical: Cys145