Effect of semi-random mutagenesis at the C-terminal 4 amino acids of human interleukin-6 on its biological activity.
The carboxyl(C)-terminus of human interleukin-6 (hIL-6) has a critical role in the expression of the biological activity of this cytokine. To define the structure-function relationships of this region, semi-random mutagenesis of the C-terminal Leu181-Arg182-Qln183-Met184 sequence of hIL-6 was performed. The mutants were produced in Escherichia coli, renatured, and purified. Alterations of the C-terminal 4 amino acids caused a significant reduction of the proliferative effect of the mutants on MH60.BSF2 and KT-3 cells, and also led to a drastic decrease in receptor binding affinity. These results suggest the importance of a positively charged residue at position 182 or 183 and an alpha-helix at position 181 for the biological activity of hIL-6.
Yasueda
H
H
Central Research Laboratories, Ajinomoto Co., Inc., Kawasaki, Japan.
Miyasaka
Y
Y
Shimamura
T
T
Matsui
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002455:Cell Division; D002460:Cell Line; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011487:Protein Conformation; D011971:Receptors, Immunologic / Q000378:metabolism; D019947:Receptors, Interleukin-6; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
D015850:Interleukin-6; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6