Abstract
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.
