5605
Competition experiments demonstrated that free heparin and heparan sulfate ( HS ) , but not selectively 2 - O - , 6 - O - , and N - O desulfated heparins , prevent p17 binding to substrate - immobilized heparin , indicating that the sulfate groups of the glycosaminoglycan mediate p17 interaction .
 Chemical: sulfate; Chemical: O; Chemical: O; Chemical: N - O; Chemical: sulfate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: sulfate; Chemical: O; Chemical: O; Chemical: N - O; Chemical: sulfate