Preparation and characterization of recombinant DNA-derived human interferon-gamma.
An attempt was made to prepare a highly purified, active recombinant DNA-derived human interferon-gamma. When the protein was denatured in urea and refolded, gel filtration and sedimentation velocity experiments indicated the presence of two forms, which are different in size and are not in a rapid reversible equilibrium. The two forms could be chromatographically separated. Far-UV circular dichroic spectra indicated the presence of secondary structures for both forms. Near-UV circular dichroic spectra revealed that the smaller form is folded into a rigid tertiary structure. The antiviral activity of the two forms of interferon-gamma showed a significant difference, i.e. the smaller form was 4-8-fold more active than the larger form. A variety of experiments show that the smaller form is more active, homogeneous, soluble, and stable than the larger form.
D004274:DNA, Recombinant / Q000378:metabolism*; D004355:Drug Stability; D006801:Humans; D007371:Interferon-gamma / Q000302:isolation & purification*; D007700:Kinetics; D008970:Molecular Weight; D011487:Protein Conformation; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000302:isolation & purification*; D013056:Spectrophotometry, Ultraviolet; D014508:Urea
D004274:DNA, Recombinant; D011994:Recombinant Proteins; D007371:Interferon-gamma; D014508:Urea