Residues K128-Q175 of human interleukin-6 are essential for its biological activity.
Internal deletion K128-Q175 of the human interleukin-6 (hIL-6) has been generated at the cDNA level. With pBV220 as expressing vector, the recombinant pBV*-DIL-6 encoding the deletion mutant (12 kD) of hIL-6 has been constructed. The resulted recombinant plasmids were then used to transform E. coli strain HB101, and the expression in the PLPR promoter system, which is temperature-regulatable, was achieved. After purification and renaturation, the biological activity of the expressed product, designated as DM120, was measured by MTT method in an IL-6-dependent cell line 7TD1. The results show that the amino acid residues of IL-6 128 to 175 are crucial for IL-6 activity. Receptor binding assay in vitro indicates that the entire region is not involved in forming the receptor binding surface.
Liu
H
H
Department of Molecular Genetics, Institute of Basic Medical Sciences, Beijing, People's Republic of China.
Duan
J
J
Wang
J
J
Peng
S
S
Zou
M
M
D017353:Gene Deletion; D006801:Humans; D015850:Interleukin-6 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017421:Sequence Analysis; D013329:Structure-Activity Relationship
D015850:Interleukin-6