Mutational analysis of the structure-function relationship in interferon-alpha.
A number of mutants of the recombinant human hybrid interferon-alpha 8[60]alpha 1[92]alpha 8 have been expressed in Escherichia coli, purified to homogeneity and characterized. The introduction of one or two negative charges results in an anomalously lower electrophoretic mobility than that expected from the molecular mass. The mutations Lys84-->Glu, Cys86-->Tyr, Cys86-->Ser, Thr87-->Ile, Tyr90-->Asp and Lys84-->Glu/Tyr90-->Asp (double mutant) result in a marked decrease of the biological activity in murine cells compared to the unmutated protein. Comparisons with published structural and homology models of interferon-beta and -alpha, imply that these residues are located primarily on the external surface of the carboxylterminus of helix C. We propose a model of interferon-receptor interaction in which these residues define a potential binding site.
Di Marco
S
S
Dept. of Biotechnology, Pharmaceuticals Division, Ciba-Geigy, Ltd., Basle, Switzerland.
Grütter
M G
MG
Priestle
J P
JP
Horisberger
M A
MA
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004252:DNA Mutational Analysis; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D016898:Interferon-alpha / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
D016898:Interferon-alpha; D011993:Recombinant Fusion Proteins