It is known that some polyphenols with anti-ice nucleation activity decrease freezing temperature of the solution containing ice nucleators, resulting in maintenance of supercooling state of the solution for a long periods. In the previous study, recombinant proteins of Erwinia ananas ice nucleation protein, inaA with histidine-tag (His-inaA) were expressed in Escherichia coli cells and ice nucleation activity was detected in the cell suspension. In the present study, the purification and the characterization of His-inaA proteins from transformed E. coli cells were done to study the mechanism of anti-ice nucleation of these polyphenols in solutions containing inaA. When the extracts of E. coli cells expressing His-inaA were fractionated into soluble, membrane and inclusion body fractions, ice nucleation activities were detected in all three fractions. Then, His-inaA was purified from the soluble fraction by affinity column chromatography and ice nucleation activity of the purified His-inaA fraction was detected. Further, it is confirmed that anti-ice nucleation activity of polyphenols was detected in solutions containing His-inaA.
