Protein Purification
Detailed methods included in supplemental material. Briefly, leaf
tissues infiltrated with cfIL-22 or pBK empty vector (negative control)
were subject to a three-step purification process. Total soluble protein
was extracted from the tissues, then taken through a two-step ammonium
sulfate precipitation. This was followed by nickel affinity
chromatography, and finally separation on a size exclusion column. The
final fraction was then concentrated and sterile filtered for use in
bioassays