2090
The core cysteine is key to the major PTP conformational epitope , but disulfide bonding contributes little to IA - 2A epitope integrity .
 Chemical: cysteine
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: cysteine