24609
The biological function of proteins is strictly related to their molecular flexibility and dynamics : enzymatic activity , protein - protein interactions , ligand binding and allosteric regulation are important mechanisms involving protein motions .
 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