17496
To test the role of the loop linking the S3 helix and the S4 helix in voltage sensitivity , we have constructed a set of mutants of the rat Kv1 . 2 channel that vary solely in the length and composition of the extracellular loop that connects S4 to S3 .
 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