Structure of monomeric Interleukin-8 and its interactions with the N-terminal Binding Site-I of CXCR1 by solution NMR spectroscopy

• Published in: Journal of biomolecular NMR Vol. 69; no. 3; pp. 111 - 121
• Main Authors: Berkamp, Sabrina, Park, Sang Ho, De Angelis, Anna A., Marassi, Francesca M., Opella, Stanley J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2017; Springer Nature B.V
• Subjects: Aqueous solutions; Binding Sites; Biochemistry; Biological and Medical Physics; Biophysics; Chemokines; Dimerization; Humans; Interleukin 8; Interleukin-8 - chemistry; Interleukin-8 - metabolism; Lipid Bilayers; Magnetic resonance spectroscopy; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nuclear Magnetic Resonance, Biomolecular; Phenylalanine; Physics; Physics and Astronomy; Polypeptides; Protein Binding; Receptors, Interleukin-8A - metabolism; Residues; Spectroscopy; Spectroscopy/Spectrometry; Spectrum analysis; Chemokine; Nanodisc; GPCR; CXCL8; IL-8; Protein structure
• ISSN: 0925-2738; 1573-5001
• DOI: 10.1007/s10858-017-0128-3

The structure of monomeric human chemokine IL-8 (residues 1–66) was determined in aqueous solution by NMR spectroscopy. The structure of the monomer is similar to that of each subunit in the dimeric full-length protein (residues 1–72), with the main differences being the location of the N-loop (residues 10–22) relative to the C-terminal α-helix and the position of the side chain of phenylalanine 65 near the truncated dimerization interface (residues 67–72). NMR was used to analyze the interactions of monomeric IL-8 (1–66) with ND-CXCR1 (residues 1–38), a soluble polypeptide corresponding to the N-terminal portion of the ligand binding site (Binding Site-I) of the chemokine receptor CXCR1 in aqueous solution, and with 1TM-CXCR1 (residues 1–72), a membrane-associated polypeptide that includes the same N-terminal portion of the binding site, the first
trans-
membrane helix, and the first intracellular loop of the receptor in nanodiscs. The presence of neither the first transmembrane helix of the receptor nor the lipid bilayer significantly affected the interactions of IL-8 with Binding Site-I of CXCR1.