16689
Metal catalyzed oxidation via the oxidative system Cu ( 2 + ) / ascorbate is known to induce aggregation of therapeutic proteins , resulting in enhanced immunogenicity .
 Chemical: Cu ( 2 + ); Chemical: ascorbate
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: Cu ( 2 + ); Chemical: ascorbate