Identification of core functional region of murine IL-4 using peptide phage display and molecular modeling.
Murine IL-4 is a pleiotropic cytokine with undefined core functional region for eliciting downstream signaling. We used molecular modeling to predict the binding sites recognized by an anti-IL-4-neutralizing mAb (11B.11) and peptide phage display to delineate their makeup. The results of these approaches were confirmed by site-directed mutagenesis analysis. The results suggest that the amino acid residues spanning from 79 to 86 (QRLFRAFR) on IL-4 are of the major binding site for 11B.11. Furthermore, the functional experiments demonstrate that the residues R80, R83 and R86, which are located in the helix C of murine IL-4, play a crucial role in binding to the IL-4R alpha-chain. Taken together, a new core functional region of murine IL-4 is identified, which provides new insight into the interaction between IL-4 and IL-4Ralpha. In addition, the results demonstrate that 11B.11 binds to a core functional region of murine IL-4, which prevents this cytokine from interacting with its cognate receptor.
Yao
Gang
G
Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
Chen
Weiyan
W
Luo
Haibin
H
Jiang
Qunfeng
Q
Xia
Zongxiang
Z
Zang
Lei
L
Zuo
Jianping
J
Wei
Xin
X
Chen
Zhengjun
Z
Shen
Xu
X
Dong
Chen
C
Sun
Bing
B
D019943:Amino Acid Substitution; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism*; D001665:Binding Sites; D018604:Epitope Mapping; D015847:Interleukin-4 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D016297:Mutagenesis, Site-Directed; D019151:Peptide Library; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D053662:Interleukin-4 Receptor alpha Subunit
D000911:Antibodies, Monoclonal; D015847:Interleukin-4; D019151:Peptide Library; D011956:Receptors, Cell Surface; C504002:Il4ra protein, mouse; D053662:Interleukin-4 Receptor alpha Subunit