62] Purification of human fibroblast interferon prepared from modified fibroblasts

Abstract

This chapter presents the purification of human fibroblast interferon prepared from modified fibroblasts. Human fibroblast interferon (batches of 50 to 200 million units per week) is produced from C-10 cell cultures. The interferon is used for elucidating methods for its purification to homogeneity. It is then used to investigate ways in which the purification procedures might be modified to increase the yield of pure interferon. The pure protein is accumulated for chemical analyses. Data on the amino acid composition and NH 2 -terminal amino acid sequence of C-10 human fibroblast interferon are now available. The major weakness with the purification by Con A chromatography and with the purification of other interferons concerns the use of a single parameter to show that the purified product is homogeneous, namely, the demonstration of interferon activity to one or more protein fractions during SDS-PAGE. The problem with introducing another parameter––for example, the homogeneity of net electrical charge––is that interferon usually does not migrate as a singular discrete fraction in electrophoresis.