Human interferon-alpha proteins (IFN α) are gene expressed cellular proteins that respond to viral infections, tumors and other biological inducers. This type I interferon protein has been developed as a biological, therapeutic drug for the treatment of hepatitis-C, cancers and other diseases. Structurally, it is part of the helix cytokine family. The molecular weight of individual interferon protein varies from 19 to 20 kDa which consist of a length of 165 to 166 amino acids long. The Interferon-alpha protein is also heterogeneously expressed in the E-coli cell surface as an incursion protein. In the past, the immobilized, antibody affinity column purification was the first step to separate target recombinant proteins (rIFN α) from cell extraction fluid. However, the immuno-affinity column binding mechanism for protein purification was not well understood in the 1990s. Recently in 2015, the structure model of the interferon-alpha protein epitope binding interface with a neutralizing monoclonal antibody, was determined using X-Ray protein crystallography. In this presentation, protein structure analysis using the RCSB protein database (code: 3UX9 and 1IGY) and Swiss PDB viewer molecular model software was conducted for the analysis of interferon-alpha antibody binding domains in Loop AB (24 -43 AA) and Helix E (140-150 AA), against the immunoglobulin Fab site between hyper variable loops from heavy chains and light chains which attach to a beta-sheet of immunoglobulin domain. The molecular level analysis provides structural rationale to interferon-alpha binding specificity and affinity properties to the complement medium found in antibody column elution profiles. Additionally, the structure base analysis to study the variety of heterologous-produced interferon-alpha proteins due to protein folding, oligomer formation, and protein post-translation in the downstream purification steps will be discussed.

Structure base analysis of production and purification of human leukemia interferon

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.