544
Circular dichroism analysis reveals that NO induces a profound conformational change in p21ras in association with GDP /GTP exchange .
 ( DNA: p21ras, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( DNA: p21ras, None) 