Construction of a modified murine interferon alpha with increased stability.
The mutant [Ser86] murine interferon alpha A was constructed by oligodeoxyribonucleotide-directed site-specific mutagenesis and expressed under the control of lambda phage PL promoter in Escherichia coli. The effect of the substitution of serine for the cysteine residue at position 86 in the murine interferon alpha A was studied. It was observed that the mutant Ser86 murine interferon alpha A which does not contain the free cysteine residue in the peptide was inactivated more slowly than its parent with a free cysteine residue at position 86. Heat-inactivated murine interferon alpha A cannot be reactivated, but the heat-inactivated Ser86 derivative can be reactivated significantly to about 27.5 per cent of the original activity in the presence of sodium dodecylsulfate. These results suggest that the free cysteine in the peptide is a factor contributing to the instability of the protein.
Li
B L
BL
Department of Molecular Genetics and Microbiology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway.
Schwartz
B
B
Pestka
S
S
D010582:Bacteriophage lambda / Q000235:genetics*; D001483:Base Sequence; D003545:Cysteine / Q000378:metabolism; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D006358:Hot Temperature / Q000009:adverse effects; D007370:Interferon Type I / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009152:Mutagenicity Tests; D010957:Plasmids; D011994:Recombinant Proteins; D012694:Serine / Q000378:metabolism; D014162:Transfection; D014762:Viral Interference
D004274:DNA, Recombinant; D007370:Interferon Type I; D011994:Recombinant Proteins; D012694:Serine; D003545:Cysteine