24556
Site - specific O - glycosylation on the MUC2 mucin inhibits cleavage by the Porphyromonas gingivalis secreted cysteine protease ( RgpB ) .
 O, cysteine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 O, cysteine