21563
Kinetic analysis revealed that the mutation affected the substrate specificity of the enzyme and reduced its K0 . 5 for selected halogenated substrates by a factor of 2 - 4 , without impacting the rate - determining hydrolytic step .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None