1877
The second order rate of alkylation of thioredoxin - ( SH ) 2 with 1 eq of iodoacetic acid was pH - dependent and showed independent initial reactions of one thiolate ion with a pK value of 6 . 7 and a second with a pK value close to 9 . 0 .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
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