Purification and structural analysis of interferon.

Studies with crude or partly purified interferon have provided a significant amount of structural information. However, complete biochemical characterization required purification to homogeneity. Earlier work on fractionation has met with many difficulties because interferon was available only in minute quantities. A scale-up of production, adaptation of multi-step purification schemes, use of high-resolution separation techniques and highly sensitive analytical methods have yielded pure interferons and hence many structural data. Specific activities, amino-acid compositions, partial sequences and structural homologies of many interferons were determined. Finally, cloned copy DNA (cDNA) fragments derived from specific interferon mRNA, as well as isolated interferon genes, have been sequenced and the data were used to elucidate complete sequences of many interferons with a high degree of confidence.