19004
In contrast , noncompetitive inhibition by a UbcH7C86A product analog ( Ki = 7 +/- 0 . 7 mu m ) and substrate inhibition at high concentrations require two functionally distinct E2 ~ ubiquitin substrate binding sites .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None