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