4701
Our study was addressed to the synthesis of some derivatives of this sequence in order to obtain both peptide substrates suitable for the detection of the Src - like tyrosine kinase activity and active site - directed inhibitors specific for this class of enzymes .
 Src, tyrosine kinase
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 Src, tyrosine kinase