15529
We found that all double mutations ( H31R / E36D , H31R / E41A and E36D / E41A ) made the molecules sweeter than des - pE1M - brazzein and three single mutants .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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