Reference

Stable isotope aided nuclear magnetic resonance study to investigate the receptor-binding site of human interleukin 1b

Stable isotope aided nuclear magnetic resonance study to investigate the receptor-binding site of human interleukin 1b. Tate, Shinichi; Ichikawa, Saori; Kaneko, Midori; Masui, Yoshihiro; Kikumoto, Yoshikazu; Kamogashira, Takashi; Ouchi, Muneki; Takahashi, Seizo; Inagaki, Fuyuhiko (Tokyo Metrop. Inst. Med. Sci. 97599-21-8 are also occured in this study., Tokyo 113, Japan). Biochemistry, 31(8), 2435-42 (English) 1992. CODEN: BICHAW. ISSN: 0006-2960. DOCUMENT TYPE: Journal CA Section: 15 (Immunochemistry) Resonance assignments for interleukin 1b at neutral pH were made by using three-dimensional NMR in combination with specific labeling and double-labeling methods with stable isotopes. On the basis of the present assignments, 15N single-quantum coherence spectra of N-terminal truncated and fusion mutants were compared with that of the wild-type. Although these mutants have reduced biol. activity, they showed 15N-SQC spectra similar to that of the wild-type. However, small but significant chem. shift changes were obsd. for amino acid residues within a loop 86-99, in spite of the modification at the N-terminus, supporting the idea that this loop forms a biol. active part of interleukin 1b. Receptor-binding activity was studied for mutants (Asp-93)-, (Leu-83)- and des-(Arg-98)interleukin 1b's. The results show significant loss of the receptor-binding activity. The N-terminal, the C-terminus, and the loop 86-99 form a part of the open end of a b-barrel (Finzel, B. C., et al., 1989; Clore, G. M., et al., 1991), which forms the receptor-binding site of IL-1b. .