857
In this study , we established an Escherichia coli expression system , which produced a large amount of tagged human liver prolidase that was purified to over 95 % purity from the soluble fraction of cell lysate by affinity chromatography on Streptavidin - agarose resin .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None