Optimization of the Purification Process of Interleukin-31

Shiran Tabachnik, Chemical Engineering, Shenkar College of Engineering and Design, Ramat Gan, Israel
Michal Amrani, Chemical Engineering, Shenkar College Of Engineering And Design, Ramat Gan, Israel

Interleukin-31 (IL-31) is a relatively newly discovered cytokine that is secreted, mostly, by activated T helper type 2 (Th2) immune cells. 

It has been recently demonstrated that IL-31 can serve as an anti-cancer agent. This protein result from the expression of recombinant DNA within living cells.

Due to financial consideration, the research is not based on the commercial recombinant mouse IL-31 (rmIL31) and the production of mouse IL-31 (mIL31) occurs in the lab.  

The half-life of mIL31 in mice blood is very short, therefore the IgG heavy chain fragment was fused to the mIL31 protein.

Purification of both recombinant mIL-31 proteins (either with or without IgG fragment) was tested in the past, using Immobilized Metal-Affinity Chromatography (IMAC), with Nickel beads as Stationary phase and Imidazole solution as mobile phase. Although purity level of the product was not satisfying.

Our research deals with the optimization of the current laboratory purification method. Among the main methods examined were the addition of salt to the buffers in the affinity method, the use of Imidazole's concentrations gradient in the elution phase, and a combination of affinity and ion exchange chromatography.