6174
The Mn ( 2 + ) containing enzyme was about 30 - fold more efficient with paraoxon as substrate and more stable than the Cd ( 2 + ) counterpart , even though the Mn ( 2 + ) affinity for the binuclear metal centre is apparently lower .
 Mn ( 2 + ), paraoxon, Cd ( 2 + ), Mn ( 2 + )
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Mn ( 2 + ), paraoxon, Cd ( 2 + ), Mn ( 2 + )