4954
To investigate this , we examined conformational changes in ECL2 of the angiotensin II type 1 receptor ( AT1R ) by introducing mutations in distant sites that alter the activation state equilibrium of the AT1R .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None