23909
We synthesized a serotonin derivative to enable selective tagging of serotonylation and to investigate its effect on Ras ; the latter displayed undisrupted interaction with Raf - 1 at the Ras binding domain .
 Chemical: serotonin
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: serotonin