16897
The morpheein model of allosteric regulation draws attention to proteins that can exist as an equilibrium of functionally distinct assemblies where : one subunit conformation assembles into one multimer ; a different subunit conformation assembles into a different multimer ; and the various multimers are in a dynamic equilibrium whose position can be modulated by ligands that bind to a multimer - specific ligand binding site .
 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